y T G E o BIOLOGICAL THEORIES ABOUT WOM .EN ANOMEN H s E R ~'-J R .EVIse::'0E .:'O.. ~ TI0N ....- -'IN .CLUDESA N . EWCH.. AP T .ER.ONB . RAIN' AN ATOM,.Y,. isE :ic'0 1 .F-' '':ERI:NeE "S;AND .-H . 0' .M O .:&'EX, U .A.'I..ITy MYTHSOF GENDER BIOLOGICALTHEORIES ABOUTWOMENANDMEN SECONDEDITION ANNEFAUSTO-STERLING BASIC B BOOKSA Member of ThePerseus[looks Group Library of Congress Cataloging-in-Publication Data Fausto-Sterling, Anne,1944-Myths of gender: biological theories about women and men /Anne Fausto-Sterling-2nd ed. p.cm. Includes bibliographical references andindex. ISBN0-465-04792-0 (pbk.) 1.Sexdifferences.2.Feminism.3.Sexism. 4.Humanbiology-Philosophy.5.Prejudices. 1.Title. QP81.5.F381992 155.3'3-dc2092-53170 ISBN0-465-04790-4 (cloth) ISBN0-465-04791-2 (paper) ISBN0-465-04792-0 (second edition paper) CIP Copyright1985byBasicBooks,A Member of The PerseusBooksGroupPreface, chapter eight, and afterwordtosecondeditioncopyright@1992by BasicBooks. Allrights reserved.Printed in the United States of Amer-ica.No part of this book may be reproduced in any manner whatsoever without written permission except in the case ofbrief quotationsembodiedincriticalarticlesandre-views. For information, address BasicBooks, 387 Park Avenue South, New York, NY10016-8810. Designed by Vincent Torre Formyparents, PhilipandDorothy Sterling, whohavesharedwithme theirvisionsof theworld, includingitspastshamesandglories, itspresentpainsandwonders, anditsfuturecommunity CONTENTS PREFACETOTHESECONDEDITION vi ACKNOWLEDGMENTS viii TheBiological Connection:AnIntroduction3 2 AQuestionof Genius:AreMen ReallySmarter Than13 Women? 3 Of GenesandGender61 4Hormonal Hurricanes:Menstruation,Menopause,and90 FemaleBehavior 5Hormones andAggression:An Explanation of Power? 123 6Putting Woman inHer IEvolutionary) Place 156 7SexandScience:AConclusion 205 8Sexand theSingleBrain:Addendum to theSecond223 Edition AFTERWORDTOTHESECONDEDITION260 APPENDIX 271 NOTES 273 GLOSSARY 296 INDEX 301 v PREFACETO THESECONDEDITION INAUGUST1991Ireceivedaphone callfromareporter:Did Iknowaboutaforthcomingarticleclaimingthathomosexualand heterosexualmenhad differentbrain structures?Would Icomment onit?Afterreceivingandreadingafaxofthearticle(itwasstill available only to the press),I discussed it at length with the reporter. Asitturnedout,thisphonecallwasthefirstofmany,andasthe timeIspent talking about thisthree-pagescientific report stretched fromhourstodays,Igrewincreasinglyfrustrated. Myfrustrationhadatleastthreecomponents.First,thepublic discussionwasnot onlyabout homosexuality but aboutgenderand sexdifferencesaswell.Thelogicwasthatmenandwomenhad differentbrains;thereforegaymenmighthavebrainsthatlooked more like those of women and lesbiansmight havebrainsmore like thoseofmen.Thequestionof sexdifferencesincognition wasone I considered in extenso in thefirstedition of thisbook,andthusto seeit leaponcemoretothe forefrontof public discussion mademe weary.Second,Iknewthatthepublicdebatewasreallyaboutthe questionofsocialequity.Shouldgaypeoplehavefullcivilrights? Shouldtheybetreatedasif theyhadadisease?Shouldlittlegirls beexpectedto perform wellinmathematics and become engineers? Aftermorethantenyearsofconservativegovernment,ongoing feministactivities,and the riseof militant gay activism,the backlash wasuponus.Havingfoughtsuchbattlesforseveraldecades,Idid notrelishhavingoncemoretoleapintothefray.Butasoneofa handfulofscientistsequippedtofightthisparticularbattle,Ifelt that I had no choice.Finally,asan intellectual problem the question ofexaminingallegedbiologicaldifferenceshasceasedtointerest me.IdealtwithitwhenIwrotethefirsteditionofMythsof Gender andhave since moved on to other things.Being forcedback intoadiscussionofbodilydifferenceshasdivertedmefrommy current intellectual endeavors, and I can hardly hide my resentment. Thereisnodenyingtheissue,however.Asthepresscallsand vi PREFACETOTHESECONDEDITION theinvitationstopublicdebatecontinued,I suggestedtomyeditor atBasicBooksthatwedoasecondeditionaddressingthislatest roundofcontroversy.Heagreed,andwhatfollowsistheresult.I haveaddedtwoentirelynewchapters:Chapter8examineswork done since1985 on sex differences,homosexuality, and the anatomy ofthehumanbrain;theafterwordselectsandupdatesissuesdealt withearlierinthebook.Ihavenotalteredtheoriginalmaterial, believingthatitstandsonitsown.Ihopethattheadditional information will help people tothink more clearly about the current roundof controversy,about politicized bodies andthebodypolitic. Anne Fausto-Sterling 25February1992 vii ACKNOWLEDGMENTS THISPROJECThastakenmorethanfouryearstocomplete Duringthattimemanypeoplehavesupportedtheworkinman' different ways.At the most tangible level,I have receivedfellowship fromtheWellesleyCenterforResearchonWomenatWellesle' CollegeandfromthePembrokeCenterforTeachingandResearcl on Women atBrown University. The BrownUniversityadministra tionhascooperatedingrantingmebothasabbaticalleaveanI leavesofabsencetoutilizethesefellowships.Otherformsa practicalhelphavecomefromthelibrariansatboththeScience andRockefellerlibrariesatBrownUniversity,whowentouta theirwaytodealwithmysometimesurgentandoftenoddbal requests.Ihavedeeplyappreciatedtheirprofessionalcompetenc' and their personalinterest inmy work.ChristinaCrosbyandCare Cohenbothdidextensivelibraryworkformeatcriticaltimesil thebook'sdevelopment,andCarolKingtypedmorethanon versionof themanuscript with great skill and,perhaps most impor tantly,withgoodhumor.Hercheerfulnessandsenseofsteadines oftenprovidedbalanceformymoremercurialself-presentation LilyHsiehkeptotherpartsofmyprofessionallifegoing,enablin: metofocuson the book. IhavehadtheextraordinarygoodfortunetobelongtotWI differentextendedfamilies,knowninformallyasthe TackyFamil' andtheAlsteadBookSociety(andEatingClub).Thegiftsofthei individual and collective friendshipshaveon occasion kept me fran drowningandhave,amongmanyotherthings,freedmetowar! onaproject~ seeminglyunendingasthisbook.TotwoBarbaras David,Bill,Marlene,Nelson,Harold,Susan,twoElizabeths,Chris tina,Don,Joan,andKaren:thanksandmayourfriendship,love andloyaltysustainusthroughoutourlives.Aspecialthanksgoe tothechildrenofthesefamiliesforsharingwithmetheiruniqUt andwonderfulvisionsoftheworld.Daniel,Michael,Luke,Karl Nathan,Toby,Bryony,andLiz:asyoudescendintotheabyssa viii ACKNOWLEDGMENTS adulthood,mayyouneverlosesightofthefreshnessandopenness of childhood. Manypeoplehaveofferedveryparticularkindsofhelp.Karen. Romer believedinmyabilitytowriteabooklong beforeIdid.She constantly encouraged me,findingin themidst of her own busy life thetime toreadand comment on twomanuscript drafts.Joan Scott fulfilledherprofessionaldutiesasaliteraryschotkchunbyputting meincontactwithmyeditor-to-be,SteveFraser.Inwritingthis bookIwaskeptfullyintouchwiththepopularpressthroughthe devotionofseveralavidmediawatchers.Myhusband,Nelson Fausto,myaunt,AliceLake,andmymother,DorothySterling,as wellasquite anumber of students and librarians at Brown University keptmepaperedwithclippingsandalertedtothelatestrelevant magazine articles.LennyErickson keptmeabreastoftheNew York Review of Booksandlentme his copy whenevernecessary.Without theirinterestandconsistenthelpmyjobwouldhavebeenmuch harder.Myfather,PhilipSterling,lenthisespeciallykeeneditorial eyet:o major parts of the manuscript,andhisinterest and suggestions havehelpedconsiderablyinthefinalshapingofthework.So,too, havetheexcellentskillsofmyeditor atBasicBooks,StevenFraser. Discussionswithhimhelpedputthebookinfinalshape.His promptandconsideratefeedbackandhisquickeyeforwhatdoes anddoesnotworkmovedthingsalong. RuthBleierandIexchangedchaptersassheworkedsimulta-neouslyonherbookScienceandGender(Pergamon,1984).Ruth generouslysharedbothherreferencesandherencouragement. Thanks,too,tothemembersofthe1982PembrokeSeminarfor theircommentsandtoHarrietWhiteheadforrepeatedlyforcing metothinkthroughmyassumptionsjustonemoretime.The followingpeoplehavealsotakentheirvaluabletimetoreadand commentonvariousdraftsofchapters:JoanScott,NelsonFausto, DorothySterling,ElizabethKirk,BarbaraJohnson,PeterSterling, Susan P.Benson,DianaJackson,Christina Crosby,ElizabethWeed, AnnetteColeman,SandyParra,JenniferZollner,LouiseLamphere, PhilQuinn,JamesMcIlwain,PeterHeywood,BarbaraMelosh, Michelle Wittig,Margaret Kidwell,RichardLewontin,CaroleOffir, PatBlough,JuliaSherman,JaneHitti,NatalieKampen,andBarrie Thorne. It is,Ibelieve,traditionaltoabsolveeveryonewhohashelped mefromresponsibilityforerrorsinthefinalbook,andofcourseI ix ACKNOWLEDGMENTS dothat gladly,knowingthatwhatisinthe book-for betterorfor worse-results ultimately from my own decision making. Whatever strengthsmay befound,however,come fromthe collectiveprocess suggested in the acknowledgments and from the help and friendship ofmanyothersnotspecifically citedinthesepages. Acknowledgments totheSecondEdition Writing isnot a soloevent.Many people helped me out.My family newspaper clippers-Dorothy Sterling,Peter Sterling,Nelson Fausto, and PaulaVogel-kept me media-wise.Byreading anearly draft of chapter8,Drs.JamesMcIlwain,WilliamByne,andPeterSterling helpedensurethatIhadaccuratelyrepresentedthedifficultworld of neuroanatomy.Drs.S.A.Tobet,ThomasFox,andWilliam Byne sharedgalleysandmanuscriptsoftheircurrentwork,enablingme tobeasup-to-dateaspossible.PeterSterlingandmyBasicBooks editorSteveFraserhelpedimprovetheoriginaldraftbyoffering insightful editorial comments. The librarians in the Brown University librarysystemwentoutoftheirwaytohelpme,andIcouldnot havedonemyworkwithoutthem.Finally,PaulaVogel'sdaily encouragement,enthusiasm,andlovehasgottenmewritingagain. ThatisadebtIcan neverrepay. x MYTHSOFGENDER 1 THEBIOLOGICAL CONNECTION: ANINTRODUCTION AsDarwin demonstrated... wemaleshavebeen bornthefittestforthreebillionyears.Fromthat constantlyon-the-makelittletreemouse[the lemur... JtoMailerthemagnificent,theDNA of themaleY chromosomehasprogrammedustolead oursisters.-EDGAR BERMAN TheCompleatChauvinist.1982 THESEaredifficulttimes.Themiddle-classfamilyofthe 1950s,headedbyahusband,managedbyawife,andenlivenedby twochildrenandacollie,isnomore.Initssteadwehavesingle-parentfamilies,contractmarriages,palimonysuits,andserialmo-nogamy.Womendemandequalpayforworkofequalvalueand takeassertivenesstraining,andfeministsorganizetochangelong-standingpoliticalandsocialstructures.Menareunsureabout whethertoexpectathankyouorasnarlwhentheyholdadoor openforawoman,andclothingdesignersofferustheworldof unisex dress.Hair length doesn't matterj the gender gapin finishing marathonracesgetssmallereveryyear;andII affirmativeaction" hasbecomeembeddedinour language.Thevarietyandrapidityof thechangessymbolizedbytheserandomexampleshavegenerated anexpresslypoliticalbacklashbytheliN ewRight,lIdoubtsabout individualidentity,andfearsof sexual obliteration-through-equality. Inresponsetosuchpersonalandsocialupheaval,professionals throughoutthecountry-scientists,journalists,economists,and 3 MYTHSOFGENDER politicians-havebeguntosearchouttherealtruthsaboutsexual differences.Andtherein liesatale. Overthe yearsphysicians,biologists,andanthropologistshave had a lot to say about women's place in the world.In the nineteenth century,somescientistswrotethatwomenwhoworktoobtain economicindependencesetthemselvesupfor"astruggleagainst Nature,,,lwhileauthorafterauthorusedDarwin'stheoryofevo-lutiontoarguethatgivingthevotetowomenwas,evolutionarily speaking,retrogressive.2 Physicians and educators alike warned that youngwomenwhoengagein long,hardhoursofstudywillbadly damagetheirreproductivesystems,perhapsgoinginsanetoboot. Withthesewarningscamegrimpredictionsabouttheendofthe (white,middle-classlhuman race.3 Ironically,feminists of the period oftenusedthesamebiologicalargumentstosupporttheirown points of view.4 Antoinette Brown Blackwell,forexample,garnered evidencefromthenatural worldtoprovethefundamentalequality ofmenandwomen,s andElizaGamblearguedoutrightforthe natural superiorityof thefemalesex.6 Today,too,manyscientistsrespondtotheissueofsexual equalityand the socialand politicalupheavalthathasaccompanied itbyofferingustheirinsights,suggestinginallsinceritythat, howeverwellintentioned,thewomen'sliberationmovementand itsfellowtravelerswantbiologicallyunnaturalchangesthatwould bringgrieftothehumanrace.Sociobiologists,forexample,suggest thatourevolutionaryhistorydeeplyaffectsourmostintimate personalrelationships.Man'snaturalsexuality sendshiminsearch ofmanysexpartners,makinghimanunstablemateatbest,while woman'sbiologicaloriginsdestinehertokeepthehomefires burning,impelling her toemploy trickeryand deceit tokeephubby fromstraying.Thebattlebetweenthesexesisancient;itsorigin lieshiddendeepinour genes.7 Onesociobiologistevenarguesthat male andfemalesexuality are sodifferent,soat odds,that it makes sense to think of the two sexesasseparate species.8 In general these scientistsemphasizedifference,thebiologicallogicofmale-female conflict,andthedimprospectsforchange. Evenphysicalviolencefitsintothepicture.Dr.Katharina Dalton,aBritishphysicianwhohasmadeanameforherselfby publicizingandtheninventingtreatmentsforsomethingshecalls thePremenstrualSyndrome,suggeststhatmonthlyhormonefluc-tuationsmaycauseafflictedwomentounknowinglyinjurethem-selves,claimingafterwardthattheirhusbandshadbeatenthem: 4 THEBIOLOGICALCONNECTION /I Alltoooftenthepatientherselfisnotfullyawareofthedistress causedbyherperiodictantrums .... Whenawomandemonstrates bruisesassignsofher husband'scrueltyitiswelltorememberthe possibilitythatthesemaybespontaneousbruisesofthepremen-struum.,,9 Biologically based argumentation has even invaded the criminal court system.Inthe trialof awomanwhohadusedanautomobile torun overandkillher boyfriend,Daltontestifiedthatthewoman hadsufferedfrompremenstrualderangementandshouldnotbe held legally responsible for her acts.Asaresult the woman received aconditionaldischargefromjail. 10Asimilardefenseisnowvalid inFrenchcourts, IIwhileintheUnitedStatesajudgerecently acquittedadentist accusedof rape andsodomy,after the defendant claimedthathisgirlfriendhadfiledthechargesduringaperiodof premenstrualirrationality.12Whethertheideathatwearemere agentsofour ownbodieswillmakedeepinroadsintothecriminal justicesystemremainstobeseen.If thisideadoestakehold,the erosion of personalresponsibilityforone'sactions-be it awoman whocommitsmurder or amanwhobattersorrapes-wouldbean inevitableconsequence. Lostalsowouldbeour society'sabilitytorecognizelarge-scale violenceasasocialproblemtobedealtwithinapublicarena.One recentstudy,forinstance,suggeststhatawomaninalargecity standsa26percent chanceofbeingrapedduring her lifetime.That statistic increases to50percent when thepossibility of rape attempts istakeninto account. 13Are we tobelievethat these statisticsresult fromthemale'sungovernablemating urge combinedwith thefalse reportingofdistraughtpremenstrualwomen?Ormustwefaceup tothe conclusion that sexual violence issomehowembeddedin the socialfabric?If we believetheformer,thenthere'snotmuch tobe done about it;if we believe the latter, we must collectively endeavor tochange theassumptionsandattitudesof our culture-a complex anddifficulttask.Clearly,what wethink aboutthe biologicalbasis of criminal violencemattersagreat deal. So,too,do our beliefsabout women's economic welfare.Amer-icanwomengrowpoorereveryyear.Currentlytwooutofevery threeimpoverishedadultsarewomen.14 Someestimatesholdthat bytheyear2000,90percentofallAmericanslivingbelowthe poverty line will be older women and young women with dependent children.Thecausesofthisincreasing"feminizationofpoverty" (astheproblemhasbeendubbed)arecomplex,butchiefamong 5 MYTHSOFGENDER themisthefactthatwomenearnonlyfifty-ninecentsforevery dollar paid to their male counterparts.Explanationsforthis statistic includebothpaydiscriminationonthejobandprejudicesthat relegatewomentoemploymentinonlythelowest-payingjob categories.Atleastthoseareamongthereasonsgivenbyboth women'srightsorganizationsandthePresident'sCommissionon CivilRights.ButconservativewriterGeorgeGilderhasanother suggestion,somethinghecallslithebiologicalfactor. IIHeargues that men arebynaturemoreaggressivethanwomen,andthatthis heightenedaggressiveness,men'slargerphysicalsize,andwhathe callslithemaleneedtodominate"combinetomakemennatural groupleaders.Furthermore,inprehistorictimesmaleshuntedto providefood,anevolutionaryhistorythatmakesthedesireto provideoneof"thedeepestinstinctsofmen."Women-who, accordingtoGilder'sversionofprehistory,stayednearthehearth tendingthekidsandwaitingforthemeattoarrive-continueto thepresentdaytowantnothingmorethantostayathome.Thus, whenwomen dowork,theysimply cannot giveitthesameall-out effortofferedbymen."Thesedifferencesbetweenthesexes,"he writes,"fullyexplainallgapsinearning./lls Fromthislineofreasoning,itwouldfollowthatemployment discrimination,althoughit mayexistfromtimetotime,haslittle todowithfemalepoverty.PhilosophyprofessorMichaelLevin carriesthislogiconestepfurtherinhisargumentthataffirmative actiontopromoteequalemploymentandincreasefemaleearning powerisbothinappropriateanddoomedtofail.Why?Because women really arebiologically inferior. ToLevin's eye the biological factsdictatethatwomencannotcompete.Thepriceforequal employment can only belower qualitywork.16 U.S.BureauofLaborStatisticsprojectionsforjobprospectsin the coming decaderevealseveral trends that concern women.In the next ten yearsthenumber ofmiddle-incomejobstraditionallyheld bywomen,suchasteacher,librarian,andcounselor,willdecrease. Incontrast,therewillberapidincreasesintwoimportantareas-low-payingservicejobs,suchasdentalandmedicalassistants,and higher-paying jobsin administration,engineering,and the computer field.17 Ifthetrendtowardincreasingfemalepovertyistobe arrested,women will have totake their share of thesehigher-paying jobs.Butwilltheybeprepared?Willtheyobtainthemathematical trainingnecessarytobecomecomputer designersandengineersto join thewell-paidmiddleclassoftheSilicon Valley? 6 THEBIOLOGICAL CONNECTION In answer to these questions,once again the question of biology loomslarge.Inelementaryschoolboysandgirlsdoequallywellin math,butinhighschoolgirlstakefewermathcoursesandoften dolesswellthandoboysonstandardizedmathtests.Oneschool ofthoughtarguesthatthisbehaviorisaresultofacomplexseries of socialfactors that impel girls to avoid the study of math.Another suggeststhattherereallyarenosex-relateddifferencestobegin with,andathirdproclaimsthelikelihoodofinnatesexdifferences inmathematicalability. ISThislastpoint of viewimplies,of course, thatunderanyconditionsmaleswilldobetterinmath,makingit likely that more males than femaleswill become scientists, engineers, and computer and technicalexperts. The roadtothese sorts of high-payingjobs-in fieldsthatwillcontinuetoexpandinthe1980s-willremainpartiallyblockedtowomenbecauseoftheirsupposed naturalmathematicaldisability.Here,too,beliefinabiological explanationforasocialphenomenon suggeststhateffortstochange theexistingsituationarefutile.Improvemathematicsandscience education?Byallmeans,yes.Butdevelopspecialprogramsto encouragegirlstostudymathandscience?Why?-itwouldbe throwing goodmoneyafterbad. Shouldwomenvoteandgotocollege?Aretheygovernedby uncontrollablemonthlyrages?Cantheycompetein thejobmarket? Attheheartofallofthesedebatesisanoldquestionabouthuman behavior.Inthepastpeopleframeditintermsofnatureversus nurture.Todayitmostfrequentlyreachesusinphrasessuchas "genetic basis" or "genetic deep structure." The idea that our genes, factorsinherited fromour parents,somehow determine whoweare and what we can become isnow so widespread that even advertisers useittohypetheirproducts.ConsidertheCalvinKleinad19 that startswiththeheadline"ThanksfortheGenes,Dad!!"Sinceone goodturndeservesanother,thehandsome,sexychildreninthisad havedecidedtogiveCalvinKleinjeanstotheirfatherforFather's Day.(Getit?JeansinreturnforGenes?) Genetic punning aside,the question of nature versusnurture-or,asitissometimesmoreponderouslyphrased,biologicalversus socialdeterminism-remains ahotly debatedtopic.Although many oftheargumentsexploredinsubsequentchaptersofthisbookare posedinthiseither/orfashion,somescientistsandsocialtheorists (myselfincluded)nolongerbelieveinthescientificvalidityofthis framework.Such thinkers reject the search for unique "root causes," 7 MYTHSOFGENDER arguing instead for a more complex analysis in which an individual's capacities emerge from aweb of interactions between the biological beingandthesocialenvironment.Withinthisweb,connecting threadsmoveinbothdirections.Biologymayinsomemanner condition behavior,but behavior in tum can alter one's physiology. Furthermore, any particular behavior can have many different causes. Thisnewvisionchallengesthehuntforfundamentalbiological causesatitsveryheart,statingunequivocallythatthesearchitself isbasedonafalseunderstandingofbiology.Thequestion,"What fractionofourbehaviorisbiologicallybased,"2oisimpossible-evenintheory-toanswer,andunanswerablequestionsdropout of the realm of science altogether,entering instead that of philosophy andmorality. Science,accordingtodefinition,isknowledgebasedontruth, whichappearsasfactobtainedbysystematicstudyandprecise observation. To be scientific isto be unsentimental,rational, straight-thinking,correct,rigorous,exact.Yetinboththenineteenthand twentiethcenturiesscientistshavemadestrongstatementsabout thesocialandpoliticalrolesofwomen,claimingallthewhileto speakthescientifictruth.Feminists,too,haveusedscientificargu-mentstobolstertheircause.21 Furthermore,researchaboutsex differencesfrequentlycontainsgrossproceduralerrors.Ina1981 articleonewell-knownpsychologistcited"ten ubiquitousmethod-ologicalproblems"thatplaguesuchwork.22 Thelistcontains strikingerrorsinlogic-suchasexperimentsdoneonlyonmales fromwhichtheinvestigatorsdrawconclusionsaboutfemales,and theuseof limited(usuallywhite,middle-class)experimentalpopu-lationsfromwhichascientistdrawsconclusionsabout allmalesor females.Perhapsthemostwidespreadmethodologicalproblemis pinningtheresultsofastudyon genderwhendifferencescouldbe explainedbyothervariables.Manyresearchersnote,forexample, thatboysdobetterthandogirlsoncollegeentrancetestsin mathematics.Foryearsscientistsconcludedfromsuchresultsthat boysarebetteratmaththanaregirls.Recently,however,several investigators havepointed out that girlstake fewermath courses in high school;thus college entrance exams pit boys with more training inmathagainstgirlswithlesstraining.Sexandcoursetakingare confounded,andtheconclusionthatboysareinherentlybetterat math remainswithout clear-cut support. Whatistheuntrainedonlookertomakeofallthis?Arethese examplesof"sciencecorrupted,"asonehistorianhascalledthe 8 THEBIOLOGICALCONNECTION misrepresentation of womeninscientific studies/.3 or dosuch cases provideevidenceforaratherdifferentviewofscience-onein whichthescientiststhemselvesemergeasculturalproducts,their activitiesstructured,oftenunconsciously,by thegreat socialissues of the day?During the past fifteen years scholars in women's studies havelookedhardatvirtuallyeveryfieldofintellectualinquiry,all thewhilefeelingmoreandmorelikethechildinthestoryabout theemperor'snewclothes.Examiningthesamematerialthatfor yearsgreatintellectshaddeemedsolid,whole,flawless,theyhave foundthemselvesasking,naIvelyatfirst,butthenwithgreater factualandtheoreticalsophistication,"But wherearethewomen?" and,"Ifyoutakewomenintoaccount,doesn'tthatchangethe wholeconclusion?"Scientificinquiry,particularlyasitpertainsto sexandgender,hasbeennoexception. If scienceasanoverallendeavoriscompletelyobjectiveand functions independently of the prevailing socialwinds,then scientists whocommitgrosserrorsofmethodandinterpretationaresimply badattheirjobs.Theproblemwiththisviewisthatflawsin researchdesignoftenshowupintheworkofintelligent,serious menandwomenwhohavebeentrainedatthebestinstitutionsin thecountry.Byallconventionalmeasures-publicationrecord, employmentinuniversities,invitationstoscholarlyconferences-theyaregoodscientists,highlyregardedbytheirpeers.Here,then, we facean apparent paradox. Some of the most recognized scientists intheirfieldshavebuiltareputationonwhatothers,myself included,nowclaim tobebadwork.One couldresolve the paradox simply by denouncing theentire scientificenterpriseasintellectually corrupt,butIfindthisanunacceptableposition.Ibelievethatthe majorityofscientistsnotonlyarehighlycapablebutthattheytry in goodfaithtodesigncareful,thoughtfulexperiments.Why,then, dotheyseemtofailsoregularlywhenit comestoresearchonsex differences? Theanswermaybefoundif,ratherthansimplydismissing theseresearchersasbadat their trade,we thinkabout what theydo as"conventionalscience."Inanalyzingmale/femaledifferences thesescientistspeerthroughtheprismofeverydayculture,using thecolorssoseparatedtohighlighttheirquestions,designtheir experiments,andinterprettheirresults.Moreoftenthannottheir hiddenagendas,non-consciousandthusunarticulated,bearstrong resemblancestobroadersocialagendas.Historiansofsciencehave becomeincreasinglyawarethateveninthemost"objective"of 9 MYTHSOFGENDER fields-chemistry and physics-a scientist may failto see something that isright under his or her nose because currently accepted theory cannotaccountfortheobservation.24 Althoughnoonecanbe entirelysuccessful,allseriousscientistsstrivetoeliminatesuch blind spots. The prospects for success diminish enormously, however, whentheareaofresearchtouchesoneverypersonally.Andwhat couldbemorepersonally significantthan oursenseofourselvesas maleor In the study of gender(likesexuality andrace)it is inherentlyimpossibleforanyindividual todounbiased research. What,then,istobe Wecouldcallforabanonall researchintosexdifferences.Butthatwouldleavequestionsof genuinesocialandscientificinterestunanswered.Wecouldclaim anagnosticposition-thatallresearchisgoodforitsownsake-butnoonereallybelievesthat.Scientistsmakejudgmentsallthe time abouttheimportance of particular linesof research,andthose deemedfrivolousor otherwise insignificantfailtoreceivefunding. Weought,therefore,neithertoimposeresearchbansnortoclaim agnosticism.Instead,weought to expect that individualresearchers willarticulate-bothtothemselvesandpublicly-exactlywhere theystand,whattheythink,and,mostimportantly,whattheyfeel deepdownintheirgutsaboutthecomplexofpersonalandsocial issuesthatrelatetotheirareaofresearch.Thenletthereader beware.Thereadercanlookatthedata,thinkaboutthelogicof theargument,figureouthowthestartingquestionswereframed, and consider alternate interpretations of the data.Bydefinition, one cannotseeone'sown blindspots,thereforeonemustacknowledge theprobabilityoftheirpresenceandprovideotherswithenough information toidentifyandilluminatethem.Inasense,whatIdo throughoutthisbookistakeaflashlightandshineitintheunlit cornersof other people'sresearch. SinceIexhortotherscientiststospellout theirbeliefs,tostep out frombehindthemaskofobjectivity,it behoovesmetodothe same.Ihavebeentrainedtodolaboratoryresearchinafield technically designated asdevelopmental genetics. The arearepresents acrossbetweenembryology-thestudyofthedevelopmentfrom single egg cellsinto complex, many-celled organisms-and genetics, thestudyofthemechanismsofinheritance.AsascientistIam inevitablyamaterialist.TomymindWesternscienceprovidesa particular (butnot the only)description of amaterial reality that in manyrespectsmakessensetome.Despitemygeneralacceptance of Western scientific thought,I findthe available concepts and tools 10 THEBIOLOGICALCONNECTION ofmodernscienceinadequatetodescribecertainkindsofreality, especiallythosethataremultiplydetermined-thatis,thosefor whichaparticularendmaybereachedbyanumberofalternate pathways.Complex socialbehaviorisoneexample. AsauniversityfacultymemberIspendaconsiderableamount oftimeintheclassroomsharingwithstudentssomeofthethings Iknowand,moreimportantly,helpingthemgainlearningskills whichtheywillcontinue touselong aftertheyleavecollege.When IfirstbegantoteachIconcentratedonhelpingmystudentslearn aboutembryology.Inrecentyears,however,Ihavebeguntoteach twonewsubjects;thebiologyofgender,inwhichweexplorethe expressionofgenderanditsevolutionthroughouttheanimaland plantkingdoms,andatopicalcoursethatexaminesavarietyof socialissuesinbiology,includingthecontroversyoverraceand intelligenceandthesociobiologydebate.Such courses clearlyrelate toanotherimportantaspectofmyprofessionallife-thinking and writingabout the biologyofgenderin humans,aboutthe sociology of science,andaboutfeminismandscience.Theseinterestsinturn stem frommylifeasapoliticalactivist.Sincethelate1950sIhave participatedinthecivilrights,antiwarrVietnam),andwomen's liberationmovements,allofwhichseemedtometobeameans towardreachingthegoalofaworldinwhichmenandwomenof allracesliveinsubstantialsocial,economic,andpoliticalequality. Mybeliefinsuchafutureisoflongstandingandisdeeplyheld. Thereaderisbynowinapositiontoaskmeatoughquestion. Ihavementionedscientistswhofailtomaintaintheirobjectivity, suggesting that blindspots are aninherent aspect of scienceandare mostfrequentanddangerouswhenonestudiessociallyurgent topics.In writing this book,amIguiltyfromafeministstandpoint ofjustwhatIaccuseothersofdoingfromanonfeministone?My answer,ofcourse,mustbeno.InthisbookIexaminemainstream scientific investigationsof gender by looking closely at them through the eyes of a scientist who isalsoafeminist.Because of my different angleofvision,Iseethingsabouttheresearchmethodsand interpretationsthatmanyothershavemissed.Oncepointedout, muchofwhatIhavetosaywillseemacceptable,eventothose whoseresearchIcriticize;butsomeofwhatIwritewillbe controversial.Intheend,theresolutionofsuchcontroversyoften dependsuponone'sstandardofproof,astandarddictatedinturn bypoliticalbeliefs.Iimposethehigheststandardsofproof,for example,onclaimsaboutbiologicalinequality,myhighstandards 11 MYTHSOFGENDER stemmingdirectlyfrommyphilosophicalandpoliticalbeliefsin equality.Ontheotherhand,giventhesameclaims,ascientist happierwithpresent-daysocialarrangementswouldnodoubtbe satisfiedwithweakerproof.Howmuchandhowstrongtheproof one demands before accepting a conclusion isamatter of judgment, ajudgment that isembeddedin thefabricof one'sindividual belief system. Inthepagesthatfollowwewilllookcloselyatmany scientific claimsaboutmen and women.Wewill start with the assertion that maleandfemalebrainsdifferphysically,withtheresultthatthe membersofeachsexendupwithdifferentabilitiesforverbalizing anddoingmathematicalwork.Sinceattheheartofthisandother arguments isthe idea that genes cause behavioral differences between thesexes,wewillaskjust whatismeantbytheideaofgenetically causedbehavior.Atthesametimewewillalsoseewhatisknown about the embryological development of gender differences. Women's hormonal upsanddowns,some would say,makethem emotionally unstable,whilemen'shormonesmakethemthemoreaggressive sex.Butistherescientificevidencetosupportsuchideas?Finally, wewilllookatabodyofthoughtthat,withintheframeworkof knowledgeabouthumanevolution,triestofindexplanationsfor present-day male/femaleinterrelationships.For each of thesetopics we will not only discuss the views of some scientists and physicians, wewillaskjusthowwellthescientificliteraturebacksupa particular viewpoint. Thisbookisascientificstatement andapoliticalstatement.It couldnotbeotherwise.WhereIdifferfromsomeofthoseItake totaskisinnotdenyingmypolitics.Scientistswhododenytheir politics-who claimtobeobjectiveandunemotionalaboutgender whilelivinginaworldwhereevenboatsandautomobilesare identifiedbysex-arefoolingboththemselvesandthepublicat large.Throughtheirpublicpronouncements,throughtheirarticles in theNew YorkTimes,throughtheirclaimstoholdanapolitical, scientific truth,through their effortsto construct biological connec tionswheretherearenone,suchscientistsdivertattentionfrom someofthemostpressingpoliticalissuesofour time. 12 2 AQUESTIONOFGENIUS: AREMENREALLY SMARTERTHANWOMEN? Thereisperhapsnofieldaspiringtobescientific where flagrantpersonalbias,logicmartyredinthe causeof supportingaprejudice,unfounded assertionsand evensentimentalrotanddrivelhave run riottosuchanextentashere. -HELEN THOMPSONWOOLLEY Psychologist,1910 Itwouldbedifficulttofindaresearchareamore characterizedbyshoddywork,overgeneralization, hastyconclusions,andunsupportedspeculations. -JULIASHERMAN Psychologist,1977 JOBSANDEDUCATION-that'swhatit'sreallyallabout. Atthecruxofthequestion"Who'ssmarter,menorwomen?"lie decisionsabouthowtoteachreadingandmathematics,about whetherboysandgirlsshouldattendseparateschools,aboutjob andcareerchoices,and,asalways,aboutmoney-howmuchem-ployers will have to pay to whom and what salaries employees,both maleandfemale,cancommand.Theseissueshaveformedan unbrokenbridgespanningthelengthofacentury.Acrossthat passageway,yearinandyearout,havetruckedthousandsupon thousandsofpageswrittentoclarifyourunderstandingofthe intellectualabilitiesofmenandwomen.Hundredsofthisnation's topeducators,biologists,andpsychologists havedone thousands of 13 MYTHSOFGENDER studiesofferingusproofs,counterproofs,confirmations,andrefu tations.Yetthebattlerageswithasmuch heat andaslittle lightas ever. Today'sclaimsarequitespecific.Thesciencefeaturepageof theBostonGlobehadthefollowingheadlineinanarticleon education: ISMATH ABILITYAFFECTEDBYHORMONES?Farmore boysthan girlsgettopscoresin mathtest. I In the same vein a mathematics teacher in a Warwick, Rhode Island, highschoolwrites: Asamathematicseducator withover25yearsindealingwithfemale pupils and femalemathematics teachers, I dohave direct evidence.. mathematicsisthe waterinwhichallintellectual creativity mustmiJI tosurvive.Females,bytheirverynature,areoleaginouscreaturesin thisregard.Or ... asthe songsays:"Girlsjust wanna havefun.,,2 Theories abound that there aremore male than femalegeniuses and that boyswindupaheadofgirlsintheclassroomandhenceinthe jobmarket.Why?Because,somewouldhold,hormonaldifferences between the sexescause differencesin brain structure andfunction These in turn lead to differences in cognitive ability.Boys supposedly developgreatervisual-spatialacumen;girlsdevelopbetterverbal andcommunicationskills.Althoughmanyresearcherstakesuch differencesforgranted,myownreadingofthescientificliterature leaves me in gravedoubt about their existence.If sexdifferencesin cognition existatallthey arequitesmall,andthequestionof theil possibleoriginsremainsunanswered.Nevertheless,theclaimof differencehasbeenandcontinuestobeusedtoavoidfacinguptc veryrealproblemsinoureducationalsystemandhasprovided:; rationalefordiscriminationagainstwomenintheworkplace.The issue of cognitive differences between the sexesisnot new. andeducatorsusedversionsofthisparticularscientifictaleever: before the turn of the century. In1903JamesMcKeenCattell,aprofessoratColumbiaUni versityandeditorofScience,theofficialjournaloftheArnericar AssociationfortheAdvancementof Science,notedthatamonglist of one thousandpersonsof eminence throughouttheages,onl) thirty-twowerewomen.AlthoughCattellexpressedsomesurprise atthedearthofeminentfemales,hefeltthatitfitwiththefacl that in his American Menof Scienceonly atiny number of womer 14 AQUESTIONOFGENIUS Number of I nd ividuals Lower than Average Score Average Score FIGURE2.1 Genesis oftheBell-shapedCurve Higher than Average Score appearedamongthetopthousandscientists.Fromhisstandpoint "there[did]notappeartobeanysocialprejudiceagainstwomen engaginginscientificwork,"hencehefoundit"difficulttoavoid theconclusionthatthereisaninnatesexualdisqualification. 11.1 AnotherColumbiaprofessor,EdwardL.Thorndike,aninfluential educationalpsychologistandapioneerintheuseofstatisticsin educationalresearch,alsocommentedonthelackofintellectually giftedwomen.Asanadvocateofeducationalefficiency,hesaw littlesenseinsquanderingsocialresourcesbytryingtotrainso manywomentojointheintellectualelite.Anexceptionalfemale could becomeanadministrator,politician,or scientist,but the vast majoritywerebetterofflearningtobecomenursesandteachers where,asheputit,"the averagelevelisessential."4 ThorndikeandCattellboththoughtthatbiologicaldifferences betweenthesexesexplainedtherarityofextremelyintelligent women.Men,itseemed,werebynaturemorevariableandthis variabilitycreatedmoremalegeniuses.Sincethelineofreasoning mayatfirstseemtortured,awordofexplanationisinorder. Researchersgiveteststogroupsofindividuals.If onedisplaysthe number ofpeoplewithaparticulartestscoreonagraph,asshown infigure2.1,thedistribution of performances usuallyapproximates abell-shapedcurve.Thehighestpartofthecurve,showingthe scores most frequently attained, represents the average performance. J 5 Number of Individuals AverageScore FIGURE2.2 MYTHSOFGENDER /MoreVariablePopulation Bell-shapedCurves ofPopulationswith the Same Average Trait but with Different Degreesof Variability Individualswhosescoresfalltotherighthaveperformedabove average while those whose scores fallto the left were below average. Thereis,however,morethanonewaytoreachanaverage.On atestinwhichthehighestpossiblescoreis100,forexample,the averagemightbe50.If theaverageresultedfromthefactthat everyonescoredverycloseto50,thebell-shapedcurvewouldbe verytallandnarrow.If, on theother hand,theaveragescoreof50 resultedfromapopulation of individuals,some of whom scoredin the90sandsomeofwhomscoredintheteens,theshapeofthe bellwould be low and squat (seefigure2.2).In the former example, wherealloftheindividualscoreshoverrightaroundthegroup average,thestandarddeviationfromthemeanissmall,whilein thelattercaseit isquitelarge.Apopulation withalargestandard deviationis,quiteobviously,highlyvariable,makingitharderto predictthe performanceof anyone individualin thegroup. What doesallthishavetodowithanexcessofmalegeniuses! Thorndikeandothersagreedthatmenandwomenhadthesame averagelevelintelligence.Butmenweremorevariable;thus,their intelligencecurvelookedmoreliketheshort,squatonedrawnin figure2.2,whilethewomen'slookedmorelikethetall,narrow one.(I've exaggerated the effect to illustrate the point more clearly.) Whatcountedforthemenwastheabove-averagetailonthebell curve,containing asit must individuals whosurpassedtheabilities 16 AQUESTIONOFGENIUS ofeventhemostgiftedwomen.(Thevariabilityhypothesisalso allowsforthepresenceofagreaternumberofsubnormalmales,a factacknowledgedby both Thorndike andCattell.l The theme of variability isan old one.Before Darwin published histheoryofevolution,Westernscientistsconsideredvariabilitya liabilitytothespecies.Theyalsothoughtthatwomenconstituted the more variable sex.Darwin,however,won credencefortheideas thatpopulationswithgreatervariabilityamongindividualshada betterchanceofwithstandingtheevolutionarytestoftime,and that malesweremore likely tovarythan were females.Thus,when highvariabilitywasconsideredtobeabiologicaldrawback,itwas attributedtothefemaleof thespecies;initspost-Darwinianstatus asa biological benefit,it became amale property and males remained theprogressiveelement,theactiveexperimentersoftheirrace.In returnforrelinquishing their variability, women receivedthemantle ofconservation,becomingthepassive vesselsofracialpurity.5 Anumberofpsychologistsworkinginthefirstquarterofthe twentiethcenturypublishedcompetentscientificstudiesdisputing the claimthatmen weremore variablethan women.6 Buttheideas of Thorndike and others that women should be educated forprofes-sionssuchasnursing,socialwork,andteachingwerebackedby powerfulsocialforces.Cattell,forexample,wroteatatimewhen womenhadbeguntooutnumbermenasstudentsinmanyofthe largestateuniversities-California,Iowa,Minnesota,andTexas amongthem.?The"problem offeminization"concernededucators deeply.While administrators at the University of Chicago contained thelargegrowthinwomenstudentsbyplacingtheminaseparate collegewithintheschool,otherinstitutionsrespondedbyurging women toenter specialall-femalefields.Home economics,forone, provided anew place forthe increased number of women chemists.8 Thestructureoftheworkforcehadalsochangedmarkedly.With jobsegregationafactoflifeforwomen,9Thorndikeandothers encouragedthemassingofwomenintocertain(low-payingloccu-pationsbyurgingtheutilityofseparatevocationaleducationfor malesandfemales.Federal aidforindustrial artsprogramsforboys andhomeeconomicscoursesforgirlssupportedthisprocess.Ac-cordingtooneanalysis,"Hospitalandschooladministratorswel-comedtheseprogramsasasolutiontotheirgrowingneedfor competentbutinexpensiveworkers.Businessmensupportedthe growingnumberofsecretarialandcommercialcoursesforwomen for similar reasons."IO The biological views of Cattell and Thorndike 17 MYTHSOFGENDER weresocongenialtotheeconomicandpoliticalestablishmentof theperiodthatrational,scientificchallengestotheirworkwere studiously ignored. II Thedebateovervariabilitywentonintothe1930s,whenit finallyseemedtohave been laidtorest by Lewis Terman,an expert on mental testing.11But,like the phoenix arising fresh and beautifuJ fromtheashesofitsowncremation,thetheoryofvariabilityh ~appearedoncemoreonthemodernscene.Curiously,itsrebirth bringsoutfewnewfacts,presentingonlyasomewhatmodernized formulationofthe sameoldidea.In1972the AmericanTournaIoj Mental Deficiency published anarticle by Dr.Robert Lehrke entitled "A Theory of X-linkage of Major Intellectual Traits."ll Theediton were sensitive to the factthat the article would provoke controvers) andtookthesomewhatunusualstepofinvitingthreewell-knowr psychologiststowritecritiques,whichfollowedtheoriginalarticlt alongwitharoundofresponsefromLehrke.14 Lehrkenotedtha: thereweremoreinstitutionalizedmentallyretardedmalesthar females,anobservationmade bymanybutpoorlyunderstood.15 h it possible that parents keepretarded girlsat home more often?An boysmoresusceptibletoenvironmentalshock?Or,doestheX linkageofcertainmetabolicdiseasesmakeboysmorelikelytobf institutionalized?Lehrke's hypothesisholds that anumber of gene! relating to intellectual ability reside on the X-chromosome and that becauseofthepeculiaritiesofchromosomalinheritance,X-linkagt meansthatmaleswillexhibitgreatervariabilityinintelligence Althoughhe beginswiththesupposed excessofmentaldefectives Lehrkedoesnotshrinkfromtheimplicationthattherewouldals( bemoregenius-levelmales.Asherathersuccinctlywrote:lilti: highly probable that basic genetic factors rather than male chauvinisrr accountforatleast some of thedifferencein thenumbers of male: andfemalesoccupyingpositionsrequiringthehighestlevels0 intellectual ability."16 TounderstandsomeofthedetailsofLehrke'sargumentiti: worthwhiletoreviewtheideaofX-linkage.Malesandfemale: differgenetically.Inadditiontotwenty-twopairsof chromosome calledautosomes,femaleshavetwoX chromosomes.Males,on th. otherhand,supplementtheirtwenty-twoautosomeswithone) and one Y chromosome. Because X and Y chromosomes are associate( with thedevelopmentof gender,they aresometimesreferredtoa Hemophilia,for example,is X-linked and therefore affects boysmore frequent! than girls. 18 AQUESTIONOFGENIUS thesexchromosomes.Hemophilia,aparticularlyfamousX-linked disease,illustratestheprocessofX-linkedinheritance.Thehemo-philiagene,whichresidesontheXchromosome,existsintwo states-normalandmutant.Thenormalgenecodesforafactor thathelpsbloodtoclot,whilethemutantgenecannotaidinthe productionoftheclottingfactor.SincemalescarryonlyoneX chromosome,andsincetheYchromosomecannotcounteractthe effectofgenesontheXchromosome,amalewillsufferfrom hemophilia if he carriesan Xchromosome with themutant stateof thegene.AfemalemustcarrytwoabnormalXchromosomesin ordertobeableeder,becauseshewillbeprotectedaslongasone X chromosome carriesthenormalgene. Children,however,caninheritthemother'sabnormalXchro-mosome.Since sons derive their X chromosomes from their mothers, amothercarryingthehemophiliafactorononeofherXchromo-somesstandsaSOpercent chanceofhavingahemophiliacson.On theotherhand,sincedaughtersreceiveoneXchromosomefrom themother andtheother fromthe father,astricken girlmust have a hemophiliac fatherin addition to a carrier mother.In other words, ifhemophiliarunsinthefamily,sonswillexpressthetraitmore frequentlythanwilldaughters. Lehrkehypothesizesthat,unliketheclottingfactorgenethat exists in one of two possible states, an X-linked gene forintelligence mightexistinasmanyassixgradedstates-calledallelesinthe terminologyofgeneticists-runningfromlowertohigherintelli-gence.Afemalewouldalwayscarrytwoofthese(oneoneachX chromosome!,andtheoneevokinggreaterintelligencemightthen compromise with the one forlesser intelligence. Males,on the other hand,would only carry onealleleat atime.If that one allelecoded foralowstateofintelligence,thenthemalewouldexpressthat trait,while if the allele were one for the highest state,the individual wouldbeextremelyintelligent.AccordingtoLehrke,then,one wouldfindequallevelsofretardationorgeniusamongmalesand females.However,becauseexpressionofextremesofintelligence infemaleswould require two chromosomes with the same verylow orveryhighstateofbrightness,whileexpressioninmaleswould requirethepresenceofonlyone,alargernumberofmalesthanof femaleswould be foundwhowere either extremely dull or incredibly brilliant.Hence,the greatermalevariabilityinintelligence. 17 ThemostfundamentalassumptioninLehrke'shypothesisis thatintelligenceisaninheritedtraitcodedforbysomefinite 19 MYTHSOFGENDEr number of factors called lIintelligence genes/' This claim has evokel greatcontroversy,andmanywell-knownbiologistshavearguel convincinglythatII)itisimpossibletodefineintelligence,and(2 we have no means at our disposalto measure its genetic componen separatelyfromitsenvironmentaldeterminants.18 Lehrkebolster hisargumentbycitingtheworkofArthurJensen,whofigure heavilyinalong-standingdebateoverwhetherblacksareles intelligentthanwhites.Jensenandothersbelievethatwhitesar smarter andthateducationalenrichmentprogramsforunderprivi leged children are a waste of government money.From his comment aboutthelowerintelligenceofslumdwellers,onewouldsus pee that Lehrkeagreeswiththisconcept.19 Lehrkealsoclaimsthatth existenceofseveralX-linkedtraitsthatcausementalretardatio: provestheinheritednature of intelligence.Thisargumentinclude thehidden,circular assumptionthat mentaldeficiencyresultsfror: genesspecifictothedevelopmentofintelligence.Mypointcanb illustrated by lookingatone often citedexample,the disease calle phenylketonuria(PKU). Intheveryrecentprimaryliteraturethesimple u t o s o m ~inheritance of PKUhasbeen calledintoquestion,lbut virtuallya: geneticandmedicaltextbooks use thisdiseaseasanexample of th straightforwardinheritance ofagenethatIIcauses"mentalretard:; tion.Children born with PKU lack an enzyme called phenyl alanin hydroxylase,which converts the amino acid phenyl alanine-one c thebuildingblocksoflargeproteinmolecules-toanotheramin acid,called tyrosine.Because their cells cannot make this conversior PKU patients accumulate toxic levels of phenyl alanine-from fort tofiftytimesthenonnalamount-inthebloodandbrain.Sine thebraincontinuestodevelopactivelyevenafterbirth,itscell maybeparticularlysensitivetothispoison.Indeed,childrenwit PKU fedon a diet lacking in phenyl alanine develop fairlynorma1l1 Thequestioniswhethertheexistenceoftheinheriteddiseas phenylketonuria(orsimilardiseasesofmetabolism)providesev dencethatgenesgovernintelligence.Thatnormalintelligencen quiresnormalbraindevelopmentisobvious,buttheexistence( PKUsaysnothingaboutthepresenceofgenesforintelligence( learning.Itmerelysaysthatwhentheentirebrainispoisone during a critical period of development, the effects can be disastrou From the point of view of explaining the relationship between gem andintelligence,thisisnomoreinformativethanasserting,aftl smashing someone's headwith asledgehammer,that violencedor: 20 AQUESTIONOFGENIUS toaperson'sskullcausessubsequentmentaldullness.Thesame point can be madeforallof thegeneandchromosome defectsthat severelyaffectnormalhuman development.They giveusaglimpse of what cangowrong,buttheytellusabsolutelynothing-at least intermsofintelligence-about howthingsworkright. Arguments against the idea of intelligence genes seem sufficient to warrant dismissal of Lehrke's hypothesis.2l But he both resurrects old data and citesnewer information purporting to show once again thatmalesperformmorevariablyonintelligenceteststhando females,and those citations merit consideration.Investigating vari-abilityinIQturnsout tobearather formidabletask.Inonerecent study researcherslookedfor scientifically gifted children by holding mathandsciencecontests.Theyfoundagreaternumberofpreco-ciousboysthangirls,andtheirtopwinnerswereallmale.They noted,however,that among the precocious students the boys owned more books and equipment related to math and science,while some of the girls' parents were so uninterested in their daughters' precocity thattheydidn'tevenplantosendthemtocollege.22 The existence ofsuchsocialdifferencesbetweenthe boysandthe girlsmakesthe resultsdifficultto interpret.Furthermore,a"talent search"approach looksonlyataselect groupofstudentswhoeither volunteeredfor thecontestsorwererecruitedbyteachersorparents.Although Lehrkedoesn'tcitethisstudy,hedoesciteanolderone23 whichis subjecttothesame sortsof uncertainty. Theonlywaytogetsomesenseofthevariabilityofthe populationasawholeistodolarge-scale,nonselectivestudies. Theseareexpensiveanddifficulttodesign-there isonlyonewell-doneresearchproject of thiskind in the literature.Lehrke cites this project, asurvey of Scottish schoolchildren,to support his view that malesvarymorethandofemales.Sincethesamplewasverylarge, andsincesamplesizeisone ofthe componentsstatisticiansuseto decidewhetheraparticular differenceissignificant rather thanjust random,thesmalldifferencesinstandarddeviationfoundamong these Scottish boys and girls turned out to be statistically significant. AsoneoftherespondentstoLehrke's1972paperpointsout, however,themalevariabilityresultedmostlyfromanexcessof males with very low scores-a result, perhaps, of physical handicaps thatmighthaveinterferedwiththeirperformanceonthetimed tests.24 Lehrke'sresponseto hiscriticsismaddening.He concedesthat "each one of the arguments for X-linkage of major intellectual traits 21 MYTHSOFGENDER canbeinterpretedtoproducedifferentemphases,"but thinksthat hisemphasismeritsattention becauseitisasimpler explanation.25 Inadditiontothisweakattemptatscientificrebuttal,anddespite thefactthatsomeofhiscriticsaremale,26Lehrkealsodirectly pointsto whathethinksisthe realsource of histrouble: Determinantsofwhichviewpointapersonacceptsareundoubtedly highlycomplex,but asingle,verysimpleoneisobvious.In thesmall samplecited,allthoseacceptingthehypothesisofgreatermalevari-ability havebeenmales,aUthoserejecting it,females.17 Incontrast tohisassessmentof hisfemalecritics,however,Lehrke believeshimselftobeadispassionateobserver: I donot feelthat I must apologize forthefactthat certain implications ofthetheorymayseem... tobederogatorytowomen.LikeTopsy, thetheory"justgrowed,"itsnaturebeingdeterminedbythedata.I could not,withscientific objectivity,have changedthefinalresult.18 Here,then,wehavetheelementsofaresponsethatwillshowup againandagainindebatestoucheduponthroughoutthisbook.In eachcase,theproponentsofbiologicalexplanationsofbehavior labeltheirattackersasbiased,membersofsomespecialinterest group[women,feminists,Marxists),whilechoosingforthemselves theroleof theobjective,dispassionatescientist. BeforejudgingLehrke'sdetachment,though,thereaderought toknowalittlesomethingaboutthecompanyhekeeps.Hislast article,"SexLinkage:ABiologicalBasisforGreaterVariabilityin Intelligence,"waspublishedin1978inabookentitledHuman Variation:TheBiopsychology of Age,Race,and Sex.29 Thebook is dedicatedtothememoryofSirFrancisGalton,founderofthe eugenicsmovement,whileitsheadquotecomesfromnoneother thanE.L.Thorndike.Justasinteresting,thevolumein questionis editedbyDr.R.TravisOsborn,aleaderintheneweugenics movement,30whohasreceived,overtheyears,financialsupport froma "philanthropic" organization called the Pioneer Fund,which promotestheoriesofblackinferiorityandhassupportedthework ofDrs.WilliamShockleyandArthurJensen.IPastmembersand directorsincludeSenatorJamesO.Eastland,thesegregationist senator from Mississippi, aridRepresentative Francis E.Walter, who chairedtheHouseCommitteeonUn-AmericanActivitiesduring the anticommunist campaigns of the1940s and1950sY) Are Lehrke, Osborne,andJensen(whoalsohasanarticleinthebook!strange 22 AQUESTIONOFGENIUS bedfellowsor,asIsuspect,appropriatecompany-eachbeinga scientistwhodisclaimsresponsibilityforthesocialimplicationsof his"objective"facts? CattellandThorndikeformedpartofthemainstreamofedu-cationalpsychologywhichtothisdaycarriesalongsuchadherents asLehrke.Therewereothersinthemainstreamwhorejectedthe variabilityhypothesisbutarguedinsteadthatinnatedifferences betweenmalesandfemalesareimportantwhenconsideringwhat jobstotrainforandhowtoteach-even at theelementarylevel-such subjects asreading and writing. Among the most widely quoted compilationsofdataon sexdifferencesisonepublishedin1968by GaraiandScheinfeld.Intheintroductiontotheirbook-length literaturereviewtheyexplicitly state that their purpose islitomake theparticipationofwomeninthelaborforceasefficientastheir potentialpermits."TosummarizeGaraiandScheinfeld'sfindings intheirownwords: Females,ontheaverage,surpassmalesinverbalfluency,correct languageusage,spelling,manualdexterity,clericalskills,androte memory.Males,ontheaverage,aresuperiortofemalesinverbal comprehensionandverbalreasoning,mathematicalreasoning,spatial perception,speedandaccuracyofreactiontovisualandauditory stimulation,mechanicalaptitude,andproblem-solvingability.These sexdifferencesforeshadowthedifferentoccupationalgoalsofmen andwomenJ1.IEmphasisadded I Inaconclusionechoedinmorerecentwritingsbyotherpsycholo-gists,GaraiandScheinfeldinferthat women'sworkpreferences lie inthefinearts,literature,socialservices,secretarialjobs,and assembly-line work because these areas suit their particular aptitudes. Men,in contrast,seem drawn by their special skillstothe sciences, mathematics,engineering,mechanics,andconstruction. GaraiandScheinfeldcallforcertaineducationalreformsto accommodate their findings.They believe that boys are handicapped bycoeducationalclassesbecausetheymaturemoreslowly,while girlsaredistracted,especiallyinmoredifficultsubjects,bytheir needfor approvaland interaction with others. Their solution would beareturntosingle-sexclasses,atleastinhighschool.Garaiand Scheinfeld also suggest that there are separate feminine and masculine ways of learning subjects such asmathematics and reading,and that teachingmethodsforthesesubjectsoughttobereevaluated.This thought,too,remainscurrent.Inaresearchpaperappearingin 23 MYTHSOFGENDER Science magazine in 1976,33 psychologist Sandra Witelson concludes that boys' and girls' brains have different physical organizations and thatcurrentmethodsofteachingreading(whichstressphonetics ratherthanvisualmemory)mayfavorgirlswhilehandicapping boys.In aninterview she,too,saidthat "separate groupsor classes forthe sexeswouldbebeneficialforteachingreading.,,34 Inthisdayofincreasingcoeducation,thethoughtofresegre-gating classrooms bysexcarriesacertainirony.At thecollegelevel there isevidence that coeducation ascurrently practicedmayharm femalestudents.3s Butisthesolutiontoreturntoaseparatebut unequalformof education,l6or toidentify andremedy whateverit isaboutcoeducationthatfunctionstodiscouragefemalestudents? Ofcourseif onebelievesininnatesexdifferences,thenthelatter makesnosense. WithechoesofJamesMcKeenCattellinourears,wefind ourselves once againin aperiod in which femalesoutnumber males onthe collegecampuses.In the current political climate theenroll-mentchangeshavelednottoamovetocordonoffthefemalesas in Cattell's day,but insteadtoacallfrom studentsformorefemale facultyandbetterrolemodels.GaraiandScheinfeld,however,call forthe/I defeminizationof theelementary classroom."37Thereare, they feel,toomany women teachers whose emphasis on conformity and good behavior stiflesthe creative expression of little boys;girls, too,need more male teachers,especially if they are to be encouraged (atleastthemoretalentedones)tostudyscienceortoimprove theircreativeabilities.GaraiandScheinfeldclaimthat"almost exclusivestaffingoflibrarieswithwomenandofschoolswith womenteacherscreatels]aclimatewhichconfrontstheboywith hostilityandlackofunderstanding,"curiouslyechoingadiatribe written by Cattell in 1909 in which he,too, deplored the dominance ofthefemale"schoolprincipal,narrowandarbitrary,andthe spinster,devitalizedandunsexed"overtheschoollivesoflittle boysandgirls.38 Thus,whilefeministscallformorefemalerole models,somepsychologists callforareturn tothemale-dominated classroom.Istheretrulynoscientificevidencetotelluswhois right? 24 AOUESTIONOFGENIUS TABLE 2.1 Summary of Maccoby andlocklin'sFindingsonSexDifferences UnfoundedBeliefsAbout SexDifferences Girlsaremore socialthan boys Girlsaremore suggestible thanboys Girlshavelower self esteemthanboys Girlsarebetteratrate learning and simple repetitivetasks;boys arebetter athigher levelcognitive processing Boysaremoreanalytic than girls Girlsaremoreaffected byheredity;boysare moreaffectedby environment Girlslackachievement motivation Girlsaremoreinclined towardtheauditory; boysaremoreinclined towardthevisual OpenQuestions of Difference Tactile sensitivity Fear,timidity,and anxiety Activitylevel Competitiveness Dominance Compliance Nurturance and "maternal"behavior FairlyWellEstablished Sex Differences Girlshavegreater verbal ability Boysexcelin visual-spatial ability Boysexcelinmathematical ability Boysaremoreaggressive SOURCE:EleanorMaccoby3ndCarolNagyJacklin,ThePsychology of SexDifferencesiStanlord, Calif.:StanfordUniversityPress,19741. MaleSkills/FemaleSkills:TheElusiveDifference Thebeststartingpointfordiscussingthedifferencebetweenmale andfemaleskillsisabookpublishedin1974 bytwopsychologists, EleanorMaccobyandCarolNagyJacklin.39 Theysummarizeand criticallyevaluatealargebodyofworkonthepsychologyofsex differences,concludingthatatleasteightdifferentclaimsforsex differences(seeleft-handcolumnintable2.1)weredisprovedby theresultsof thenavailablescientificstudiesandthatthefindings 25 MYTHSOFGENDER aboutsevenotherallegeddifferences(seemiddlecolumn)were either tooskimpyor tooambiguoustowarrantanyconclusionsat all,butthatsexdifferencesinfourareas-verbalability,visual-spatial ability,mathematical ability,and aggressive behavior-were "fairlywellestablished"(seeright-handcolumn).Weturnour attention for the remainder of this chapter to the firstthree of these differences:verbal,visual-spatial,andmathematicalabilities.The fourth,aggressiveness,wewillconsiderinchapter5. VerbalAbility Manypeoplebelievethatlittlegirlsbegintotalksoonerthan dolittleboysandthattheirgreaterspeakingabilitiesmakegirls betterabletocopewiththeword-centeredsystemofprimary education.MaccobyandJacklinciteonesummaryofstudiesdone before1950thatpointstoatrendofearliervocalizationingirls. Thegenderdifferences,however,aresmallandoftenstatistically insignificant,and,infact,manyof thestudiesshownosex-related differencesatall.Intheirreviewoftheliteraturesubsequentto 1950,MaccobyandJacklinremainskepticalabouttheexistenceof sexdifferencesinvocalizationforveryyoungchildren.Althougha smallbodyofmorerecentworksuggeststhatthereprobablyis somethingtotheideathatgirlstalksoonerthanboys,40myown assessmentisthatthedifferences,if any,aresosmallrelativeto thevariationamongmembersofthesamesexthatitisalmost impossibletodemonstratetheminanyconsistentorstatistically acceptablefashion. The studies on early vocalization raise several interrelated issues in basic statisticsthatmust be understood in ordertodelvefurther into the controversies surrounding verbal and spatial abilities. Among these issues are statistical significance and its relationship to sample sizeandthesizeofdifferencesbetweenthesexescomparedwith the size of differences between any two individuals of the same sex. Thislatterissue,ofwhichpsychologistsinthefieldofcognitive differenceshavebecomeincreasinglyaware,placestheimportance of sexdifferencesin awholenewlight. One widely accepted scientific procedure forcomparing averages obtained from individual measurements of members of a population istoapply astatistical test totheinformation gathered.An average differencebetweentwo groups could occur by chance andtherefore wouldreflectnorealdistinctionbetweenthetwotestpopulations. 26 AQUESTIONOFGENIUS Arandomdifferenceisparticularlylikelyiftheindividualtrait understudyinoneor bothof thegroups variesalot(thatis,hasa largestandarddeviation).Scientistshavedevisedseveralmethods forexaminingexperimentalinformationtofindoutifaverage differencesarerealratherthanchance.Mostsuchstatisticaltests lookattwothings-thevariabilityofthepopulationsundercom-parisonandthesizeofthetestsample.If atestsampleisvery small,veryvariable,orboth,thepossibilitythatfounddifferences areduetochanceisgreat. Suppose,forexample,Isuspectthatmoremalesthanfemales haveblueeyes.Inordertotestmyidea,Ilookatthreegroupsof tenstudents(fivemenandfivewomen)borrowedfromthree differentclassrooms.Inthefirstgroupitturnsoutthattwo-thirds of themenbut only one-third of thewomen haveblue eyes,inthe secondthattwo-thirdsofthewomenbutonlyone-thirdofmen have blue eyes,while in the third classroom allfiveof themen have blueeyes,butnoneofthewomendo.Takingtheaverageofmy threesamples,Iseethat,overall,66percentofthemenhaveblue eyescomparedtoonly33percent of thewomen. Instandardscientificconventiononetriestodiscoverthe probabilitythataparticularresultcanoccurbyaccident.Because mysampleintheprecedingexamplewassmallandvariable,this probabilitywas65.6percent(calculatedusingaspecialstatistical test that takesinto account variance and sample size).Scientists use anagreed-uponalbeitarbitrarylimit,wherebyahypothesisis rejectedif theprobability of afounddifference occurring by chance exceeds5percent. Thus I must rejectthe hypothesis that more boys thangirlshaveblueeyes,asitisbasedonapoordatasample.If theprobabilityofadifferenceexistingbychanceis5percentor less, then one accepts the hypothesis and calls the results statistically significant. Statisticalsignificance,however,canmislead,becauseitscal-culationcomesinpartfromthesizeofthemeasuredsample.For example,in order toshow thattwogroups differ in performance by fourIQpoints,onemustuseasamplesizeof aboutfourhundred in each test group(that is,if the sexes were compared,four hundred boysandfourhundredgirls).GreaterdffferencesinIQcanbe shownwithsmallergroups,whileextremelylargesamplesmay revealstatisticallysignificantresults,accordingtotheconvention of5percentprobability,eventhoughtheyareintellectuallymean-ingless.Thus,inasampleof100,000malesand100,000females, 27 MYTHSOFGENDER TABLE 2.2 Sex-relatedCognitiveDifferences:VerbalReasoning in Subjects over Age Sixteen Number ofFemaleMaleNo Variable ResultsSuperiorSuperiorDifference Oetzel119661 Vocabulary 4102 VerbalProblem Solving100 General VerbalSkill4103 Abstract Reasoning411 Maccoby andJacklin 119741 VerbalAbilities15.B16 Droege 11967)2 .. 200 TOTAL40IS223 Non:JuliaSherman,Sex RelatedCognitiveDifferences:AnEssayonTheoryandEVidence ISpringfield,Ill.:Charles C Thomas,1978),40.Courtesy of Charles C Thomas,Publisher. an10differenceof 0.02pointswouldbehighlysignificant/proba-bilityof0.1percent).Butitdoesn'tactuallymatterif oneperson hasanIQof100andanotheran10of100.02, becausethe10test isnot designed tomeasuresuch smalldifferences.41 U singasomewhatunusualstatisticalmanipulation,Garaiand Scheinfeld concluded that girls were poorer at verbalreasoning than were boys.In order to reach that conclusion, they used the following approach.Theyknew that boysmaturedphysicallyat aslowerrate thandidgirls.Instudiesdoneonchildrenofthesameage,then, theybelievedthegirlstobephysicallymorematureandthusnot reallyage-matchedwiththeboys.Theyreasoned,therefore,that anyofthestudiesthatshowedboysandgirlstoperformequally actually provided proof of male superiority!41 One way to get around theproblemofdifferentmaturation agesistolook carefullyatthe studiesdoneonpeopleovertheageofsixteen,apointinthelife cycleatwhichthelargemajorityofbothboysandgirlshavegone throughpuberty.Dr.JuliaSherman hasdonejust this.Her results, reproducedintable2.2,showthatinfortydifferentstudiesof verbalreasoningdoneonsubjectsovertheageofsixteen,females didbetterinfifteenandmalesintwo,whileintwenty-threethere were nosex-relateddifferences. Twoobservationscanbemadefromthisinformation.First, whentherearesex-relateddifferencesinverbalreasoning,females 28 AQUESTIONOFGENIUS usuallycomeoutahead.Second,inthemajorityofcasesthereare no differences at all.What,then,isthe take-home message?Maccoby andJacklinchosetoemphasizethefemalesuperiorityinthecases wherethereissome difference.They are,however,perfectlyaware thatthefrequentinabilitytofindanydifferencecouldbequite important.Giventhesedata,choosingtobelieveinsex-related differencesinverbalabilityisajudgmentcallaboutwhichknowl-edgeablescientistscanverylegitimately differ. Morerecentlyseveralresearchershaverelatedthedifficultyof showingdifferencesinverbalabilitytothesmallsizeofanysuch differences.AllthepapersreviewedbyMaccobyandJacklinused whatiscalledthehypothesis testingapproacbtothestudyofsex differences.Usingthisapproach,aresearcherhypothesizesthe existence,forinstance,ofadifferenceinverbalabilitybetween boysand girls.Tests aregiven,averagescoresforboysandforgirls arecalculated,andthemeans,thestandarddeviations,andthe numberofsubjectsusedtomeasurethestatisticalsignificanceof anydifferencearepresented.Maccoby andJacklinsimplytabulated how frequentlyaparticular significant difference showed upin such studies. Sincethepublicationoftheirbook,however,anewapproach knownasmeta-analysishasbeenusedbyJacklinandothersto reevaluatetheir1974 conclusions.43 Thenewapproach looksatthe sizeofgroupdifferences,therebyallowingquestionsaboutsuch mattersasverbalabilitytobephrasedinthefollowingway:"If all youknewaboutapersonwashisorherscoreonatestforverbal ability,howaccuratelycouldyouguessathis/hersex?"Meta-analysisisahighlysophisticatedwayofevaluatingthemeaningof several interrelated studies. It issimple in principle, albeit statistically complex.Instead of calculating separately the averages and standard deviationsof malesandfemales,onelooksattheentire population ~ m l e s andfemalestogether)andestimatesthevariabilityinthe populationasawholeusingastatistic calledthe variance,whichis relatedtothe standard deviation.44 Likethe standarddeviation,the variancetellsoneabouttheappearanceofthebell-shapedcurve thatsummarizesindividualscores.Inmeta-analysis,one calculates howmuchofthevariancefoundinthemixedpopulationcanbe accountedforonthebasisofgender,andhowmuchisdueto variationbetweenmembersofthesamesexand/orexperimental error.Wehavealreadyseenwiththehypothesis-testingapproach how one can obtain ameaningless but statistically significant differ-29 MYTHSOFGENDER encebyusingaverylargesamplesize.Meta-analysisprovidesa wayoftellinghowlargeagivenstatisticaldifferenceisandthus howmeaningfulitisinreality. Using meta-analysis,then,what becomes of Maccoby and Jack-lin's"well-establishedsexdifference"inverbalability(seetable 2.1)?It teeters on the brink of oblivion. Dr. Janet Hyde,for instance, calculated that gender differencesaccountedfor only aboutIpercent ofthevarianceinverbalability,pointingoutthatthetinysizeof thedifferencecouldexplainwhysomanyofthestudiescitedby MaccobyandJacklinshownodifferenceatal1.45 Twootherpsy-chologists,Drs.RobertPlominandTerryFoch,cometothesame conclusion:"If allweknowaboutachildisthechild'ssex,we know very little about the child's verbal ability.,,46Clearly, it makes little sensetobaseeducational andcounselingdecisionsthatrelate toverbalabilityon simpleobservationofachild'ssex,ratherthan on some actualanalysisof hisor her particular capacities. Visual-SpatialPerception "Males,"onewell-knownpsychologisthassaid,"aregoodat mapsandmazesandmath .... Females,bycontrast,aresensitive tocontext.,,47Alliterative,yes,butisittrue?Again,Maccobyand Jacklinprovidethestartingpoint.Aswithverbalability,they conclude, there are no sex-related differences in visual-spatial abilities untiladolescence.Asummaryoftheirfindingsfromstudiesdone onadolescentsandadultsappearsintable2.3.Spatialabilityturns out tobesomewhat elusive,but Maccoby and Jacklin have isolated twotypes:spatial/visual/nonanalyticandspatial/visual/analytic. Somescientistsrefertothis latter skillasfieldarticulation. The evidenceforsex-relateddifferencesin visual-spatialability seemsalittlemore convincingthanthatforverbaldifferences,but theproblemof"negative"dataappearswithboth.Morethanhalf thetimenosexdifferencesshowupinthevisual/analyticstudies, butwhentheydoappeartheyalwaysfavormales.Themost consistentdifferencesmaterializefromthemostwidelyusedtest, therodandframetest.In thistestthesubjectsitsinatotallydark roominachairfacingalarge(fortyinchesonaside),vertically held,luminescentframe.Bisectingtheframeisalightedrod.In oneversiontheexperimentertiltstheframeinvariouswaysand the subject adjuststherodtothe verticalof theroom,ignoringthe immediatecontextofthetiltedframe.Inadifferentversion,the 30 AQUESTIONOFGENIUS TABLE 2.3 SpatialAbilitiesof Adolescents and Adults NumberNumber of Studie$of Studie$Number of inwhichinwhichStudiesfor MalesFemaleswhich PerformedPerformedNoDifference Skill BetterBetterWasFoundTotal Visual/Nonanalytic' 80210 Visual/ Analytic RodandFrameorSimilar Testb 70512 Embedded/Hidden Figures Test3069 BlockDesign Tests 2024 PercentageforVisual/ Nonanalytic 80%20% PercentageforVisual/ Analytic48%52% SOURCE:EleanorMaccobyandCarolNagy,acklin,ThePsychology of SexDifferences(Stanford, Calif.:StanfordUniversityPress,1974),tables 3.7and3.8 . Avarietyof differenttestsinvolvingmazes,lOglematching,and2and3 Dvisualizationwere used.The .ame testwasrarelyusedtwice. Bodyattitudetest. subject'schairistilted,andagainheorshemustmaketherod insidetheframeperpendiculartothefloor.Asseenintable2.3, MaccobyandJacklincitetwelvestudiesusingthistest.Although women never performed better than men,infiveof the twelve cases therewerenosex-relateddifferences. Dr.H.A.Witkin, the psychologist who developed andpopular-izedtherodandframetest,dubbedthosewhoperformedthem wellfieldindependentandthosewhoperformedthempoorlyfield dependent.Field-dependentpeople,Witkinandhiscollaborators held,werelessabletoignoredistractingbackgroundinformation inordertozeroinonessentials.Theysuggestedarelationship between generalintelligence,analytical ability, conformity,passivity, andvisual-spatialabilities.Morerecently,thefactthatfield-depen-dentandfield-independentpersonalitiesjusthappentocorrelate withmale/femalestereotypeshasledanumberofinvestigatorsto droptheuseoftheterms.Itisnowclearthatthesetwotests,at best,record some aspect of visual skill,but have nothing to dowith analyticalability.Witkinhimselfgaveatactileversionofatest designedtomeasurefielddependencetoblindmenandwomen 31 MYTHSOFGENDER and,exceptforonecasefavoringfemales,foundnosex-related differences.48 Some potentialforsexbiasisbuilt intothe rodandframetest. Picturethefollowing:apitchdarkroom,amaleexperimenter,a femalesubject.Whatfemalewouldnotfeeljustalittlevulnerable inthat situation?Althoughonewouldexpectexperimenter-subject interactionstobedifferentformalesandfemalesinsuchaset-up, the studies cited by Maccoby and Jacklin apparently don't takeinto account thispossibility.In one version of the test,the subjectmust asktheexperimentertoadjusttherodbysmallincrementstothe positionheorshebelievestobevertical.Alessassertiveperson mighthesitatetoinsisttothenthdegreethattheexperimenter continuetheadjustments.Closemightseemgoodenough.If itis truethatfemalesarelessassertivethan males,thenthisbehavioral difference,ratherthandifferencesinvisual-spatialacuity,could accountfortheirperformancesintherodandframetest.Atleast oneexperimentsuggeststhesexbiasoftherodandframetest. When,in asimilar test,the rod wasreplaced by a human figureand thetaskdescribedasoneofempathy,sex-relateddifferencesin performance disappeared.49 Therodandframetestisprobablythemostsuspectofthe measures used to assessmale/female differencesin spatial visualiza-tion,butpsychologistsuseothertoolsaswelltomeasuresuch skills.Intheembeddedfigurestest,theexperimentalsubjectmust findahiddenwordordesignwithinalargerbackgroundthat camouflagesit.Anothermeasure,theWechslerIntelligenceScales, isusedtoassessIQand comprisestwo tests,onemeasuring Verbal IQandtheothermeasuringPerformanceIQ.Thelatterisoften taken as an indication of spatial ability, although some psychologists believeittobeinadequateforthatpurpose. soOthertests,someof themcomponentsofthestandardIQtest,areusedtoprobethe abilitytovisualizethree-dimensionalfiguresinthemind'seye. These includethe blockdesign test,the mentalrotationtest,angle-matching tasks,and mazeperformance.Psychologistshave usedall ofthesetestswithrathersimilarresults:manytimesnosex differenceappearsbut whenit does,andif the subjectsareintheir teensorolder,malesoutperformfemales.Thenextquestionis,of course,by howm u h ~MaccobyandJacklinpointoutthat,aswithdifferencesin verbal skills, differences in spatial skills are quite small-accounting for nomore than 5percent of the variance.Expressedanother way, 32 AQUESTIONOFGENIUS if onelooksatthevariation(fromlowesttohighestperformance) ofspatialabilityinamixedpopulationofmalesandfemales,5 percentofit atmostcanbeaccountedforonthebasisof sex.The other95percentofthevariationisduetoindividualdifferences thathavenothingtodowith beingmaleorfemale.s I Despite thesmallsize of the difference,an advocate of the idea that there are naturally more male than female geniuses would have onestrongpointtomake.Ifonelooksattheentirebell-shaped curve,fromworsttobest,asmallsexdifferencemaybeofno practical interest.Suppose, though, one looks only at the upper part ofthecurve,theportionrepresentingthosehigh-levelperformers one wouldexpecttobecomemathprofessors,engineers,andarchi-tects.Assumeforamomentthatinordertobecomearespected engineeronemusthaveaspatialabilityinatleasttheninety-fifth percentileofthepopulation.Dr.Hydecalculatesthat7.35percent ofmaleswillbeabovethiscutoffincomparisonwithonly3.22 percentofthefemales.Putanotherway,currentlyavailableinfor-mation suggests that the ratio of males with an unusually high level ofspatialskillstothat offemaleswith the samehigh levelof skills might be2: I,amuch larger difference than one picksup by looking atthe entire population. 52Hyde alsopoints out,though,thatinthe UnitedStatesonlyabout1percentofallengineersarewomen.If onedidbelievethattheonlythingstandinginthewayofan engineeringcareerforwomenwastheirimmutablesex-related inferiorspatialability,onewouldstillexpecttofindwomenin aboutone-thirdofallengineeringjobs.Inshort,thedifferences between men and women in this respect remain too small to account forthetinynumberofwomenwhobecomeprofessionalmathe-maticians,architects,andengineers. What MakesaDifference? Sexdifferencesin spatial visualization dosometimes exist,even iftheydon'tamounttomuch.Thusthereisanobligationtolook intothecausesof measurable difference.Because sex-relateddiffer-encesinverbalorspatialabilitiesappearmostclearlyatthetime ofpuberty,somescientistsconcludethatthehormonalchanges associatedwithphysicalmaturationmustaffectmaleandfemale braindevelopmentdifferently.Otherspointtothesocialpressures toconformtoappropriaterolebehaviorexperiencedsointensely by adolescents. As seems so often to be the case,the same observation 33 MYTHSOFGENDER can support both ahypothesis of "natural," genetically based differ-enceandonethatinvokesenvironmentalinfluences.Couchedin theseterms,however,theclashofviewshasalltheearmarksofa sterile,evenboring,debate.Withouttryingtoresolvecompeting hypotheses,let'ssimplylookattheinformationwehaveathand aboutthedevelopmentofverbalandspatialabilitiesinlittleboys andlittle girls. Tobeginwith,thereisampleevidencethatvisual-spatial abilitiesareat. leastinpartlearnedskills.Asanexample,consider the factthatfirst-gradeboys do somewhat better than dofirst-grade girlsonembeddedfiguresandblockstestsif neitherhasseensuch testsbefore.Allowedabitofpractice,however,thegirlsimprove enough tocatch up,although the boys'scoresdonot change much. Researchersconcludefromsuchstudiesthatfirst-gradeboyshave alreadyhonedtheseskillssothatadditionalpracticedoesnot lead toimprovedperformance. 53Whyboysmightbemorepracticedis anyone'sguess,but since young boysandgirlshavequitedifferent playexperiences,onecanatleastconstructaplausiblehypothesis. Traditional male games such asmodel construction,block building, and playing catchmight playa key rolein developing visual-spatial skills, yet the relationship between play activitiesandthe acquisition ofspatialabilitieshasreceivedscantattentionfromtheresearch community. Studies done on older children alsorevealthat three-dimensional visualskillscanbelearned.Inonecasearesearcherassessedthe performanceofteenagestudentsastheybeganadraftingcourse. The expected sex differences were found,but disappeared six weeks intothe semester asthe young womenimproved. 54Inanother case teenagersshowedapositivecorrelationbetweenperformanceon testsof visual-spatialskillandthe number of drafting andmechan-ical-drawing courses taken.55 The sparse literature on the relationship between formal skill training (through certain types of course work) and informal(through certain types of play)suggests that girls often donotfulfilltheirskillpotential,butthatitwouldberelatively easytohelpthemdoso.Thehypothesisthatcertainkindsofplay andschoolactivitiescanimprovegirls'visual-spatialskillsisemi-nentlytestable,butmoreresearchsupportisneededforscientists whoareinterestedin carryingout suchinvestigations. Itseemsunlikely,however,thatplayandmechanicaldrawing are the only contributors to the development of visual-spatial skills. Some research suggests that children who experience more indepen-34 AQUESTIONOFGENIUS denceand lessverbalinteraction are likely todevelopstrong spatial skills,aresultthatdovetailswithinformationobtainedfroman-thropological studies.In avillage in Kenya,children who undertook tasks that led them away from home, such asshepherding, performed betteronseveralmeasuresofvisual-spatialabilitythanchildren remaining close tohome,suggesting that children who have awider rangeofenvironmentalexperiencesdevelopricherskills.56 Cross-culturalstudiesofsex-relateddifferencesinspatialfunctioning revealtwoadditionalskill-learningcomponents.Anthropologist J.W.Berry compared the abilities of Eskimos, Scots,and the Temne peopleofSierraLeone,pointingouttheenormousdifferencesin visualenvironmenttheyencounter.Eskimocountryisopenand evenlylandmarked(snowcoversmanypotentialreferencepoints), whilethe Temnelandiscoveredwith vegetationof variouscolors. The Eskimo,in order tohunt over large,relativelyfeaturelessareas, learnstobeawareofminute detail.Infact,theEskimolanguageis richinwordsdescribinggeometrical-spatialrelationships.It isnot surprising, then,that Eskimos outperform Temnes in tests of spatial ability. 57 Child-rearingpracticesalsodiffergreatlyinthetwocultures. Eskimosraisetheirchildrenwithunconditionallove,onlyrarely resortingtophysicalorverbalpunishment.Incontrast,the Temne emphasize strict discipline,acceptance of authority, and conformity. Eskimogirlsareallowed considerable autonomy,while Temne girls areraised even more strictly than the boysinthis highly disciplined society.Interestingly,nosex-relateddifferencesinspatialabilities showupintheEskimopopulation,althoughmarkeddifferences appearbetweenTemnemalesandfemales.Berryalsocompared othersocieties,includingsometraditionalhuntingcultures,with onesundergoing Westernization. 58Inthetraditionalculturesthere werenosexdifferencesinspatialvisualization,but differencesdid appear in some of the transitional ones.One hypothesis that emerges fromsuchworkisthatsex-relateddifferencesinvisual-spatial activitiesare strongest in societiesin which women's social(public) rolesaremostlimited,andthatthesedifferencestendtodisappear insocietiesinwhichwomenhaveagreatdealoffreedom.Along these lines consider that in the United States,sex-related differences inbothmathematicsandspatialabilitiesmaybechangingas opportunities androles for women change. The curricula of primary andsecondaryschoolshavebecomelesssex-segregatedwiththe developmentofequalathleticfacilitiesandbothboysandgirls 35 MYTHSOFGENDER taking shop,typing,mechanicaldrawing,andhomeeconomics.As these changes continue, there is no reason to believe that sex-related differenceswillremainconstantandeveryreasontoassumethat studies done in1955andin1985willhavedifferent outcomes. Howcanwesumupsomeofthefactorsinfluencingthe acquisition of spatial skills?Early child-parent interactions may well be involved.Plenty of studies show that parents treat boys and girls differently.Mothers are more likely to repeat or imitate vocalizations from a girl baby than from a boy baby, and they are also _morelikely totrytodistractamaleinfant bydanglingsomeobjectinfrontof him. 59Individual personality differencesalsoinfluence parent-child interactions.Preschoolchildrenhavedifferentplayhabits.Boys usuallyexploremoreandstayawayfromtheirparentsforlonger periodsoftimethandogirls,andcertainlydifferencesingames, toys,and amount of exploration could account in part for differences inthedevelopmentofspatialskills.Girlsoftenwearphysically restrictiveclothing,suchasfrilly,starcheddressesandpatent leathershoes,whichcontributestotheirmorephysicallylimited environment.Aschildrengrowoldertheyalsolearnmoreabout sex-appropriate behavior.Pressuresto conform are especially strong duringtheteenageyears,whensmallsex-relateddifferencesin spatial skillsfirstconsistently appear.Visual-spatialskill-dependent activities ranging from shop and mechanical drawing to mathematics andengineeringarealsostereotypedmalestrongholds,dauntingto eventhemosttalentedgirls.Thusthemanycomplexcomponents of sex-role stereotyping may besuperimposed upon and may interact withearlierdevelopmentalevents.Inshort,thereisnotanyone causeofsex-relateddifferencesinvisual-spatialskills.Thereare many causes. Only future research will tell which are truly significant. Theknowledgethataspectsofmale/femalesocializationvery likelyinfluencethedevelopmentofmale/femaledifferencesin spatialskillsshouldnot,ofcourse,ruleoutthepossibilitythat innate biologicalfactorscontribute tosuchdifferencesaswell.The argumentIhavemadetothispointistwofold:(1]thesizeofsex differences is quite small, and /21a complex of environmental factors hasalreadybeendemonstratedtoinfluencethedevelopmentof visual-spatialskills.Dowethenevenrequirethehypothesisof biologicallybaseddifferencestoexplainourobservations?Ithink not,althoughIremain opentotheideathat some smallfractionof analreadytinysex-relateddifferencecouldresultfromhormonal differencesbetweenmaleandfemale. 36 AOUESTIONOFGENIUS APlethoraof Theories:BiologicalStorytelling Despite the small size of sex-related differencesin verbal and spatial skills,theirexistencehaselicitednumerousstudiesaimedatex-plainingthemonthebasisofbiologicaldifferencesbetweenthe sexes.Scouringtheinsandouts,curvesandshapes,capacitiesand anglesofthehumanbrain,hopingtofindtraitsthatdifferinthe maleandfemaleisapastimeinwhichscientistshaveengagedfor morethanacentury.Earlystudies,whichdiscoveredthatmale brainswerelargerthanfemalebrains,concludedthatthefemale's smaller size resulted in her inferior intelligence. This logic,however, ranafoulofthe"elephantproblem":if sizewerethedeterminant of intelligence,then elephantsandwhales ought tobe in command. Attemptstoremedythisbyclaimingspecialimportanceforthe numberobtainedbydividingbrainsizebybodyweightwere abandonedwhenitwasdiscoveredthatfemalescameoutII ahead II insuchmeasurements.The greatFrenchnaturalistGeorgesCuvier finallydecidedthatintellectualabilitycouldbestbeestimatedby therelativeproportions of the cranial tothefacialbones.Thisidea, however,ranagroundonthe"birdproblem/'sincewithsucha measure birds,anteaters, and bear-ratsturn out to bemore intelligent than humans.6o Somebrainscientistsbelievedthatthefrontallobe ofthecerebrum(thepartthatsitsinthefrontoftheheadjust abovetheeyebrows-seefigure2.3)wasanimportantsiteof perceptivepowersandwaslesswelldevelopedinfemalesthanin males.Othersarguedthatevenindividualbraincellsdifferedin malesandfemales,thecerebralfibersbeingsofter,moreslender, andlongerinfemalebrains. Asneuroanatomistsbecame moreandmoreconvinced thatthe frontal lobe was the repository of intelligence, an increasing number ofreportsappearedclaimingthatthislobewasvisiblylargerand moredevelopedinmales.Onereport,in1854,concludedthat WomanwasHomoparietalis(aftertheparietallobe,whichlies towardthebackandtothesideofthehead-figure2.3)andMan Homofrontalis.Intime,however,theparietalratherthanthe frontallobegainedprecedenceastheseatof theintellect,achange 37 MYTHSOFGENDER CentralFissure FIGURE 2.3 Cerebrum andCerebellum Localization offunctionin thehuman cerebral cortex. Onlythemajor convolutions of the cortex aredrawn.Theyareremarkablyconstantfromindividualtoindividual,andprovidelandmarks in the task of mappins the distribution of spein42.8)/6females(29- everythick section;male-typicalAllen et a1. apparently59;mean =41)by ablind measurement.sexual(1989) heterosexual malessingle investigatorbehavior. than in females seN = suprachiasmatic nucleus of the hypothalamus. tSON=sexually dimorphic nucleus.May be the same asINAH-1or possibly a combination of INAH-Iand INAH-2. Set:Tobet and Fox(1992). tt Thin section =6microns,paraffin embedded; thick section=60 microns, gelatin embedded-Ifor Allen et al).(19119).For LeVay (1991)- 52microns, sucrose infiltrated frozen sectioD.Note:Different embedding process can cause different degrees of tissueshrinkage. Also reported datafrom severalindividuals,including a small group of Alzheimer'S patients,ninehomosexual men, andtwo male-to-female transsexuals. I SON=supraoptic nucleusiINAH-Ithrough INAH4=interstitial nucleus of anterior hypothalamus;INAH-1may be same asor part of SON. Swaab, D.F.,E.Fliers, and T. s.Paniman.1985. "The Suprachiasmatic Nuckus of the Human Brain in Relation to Sex, Age and Senile Dementia." Brain Research 342:37-44. Swaab,D.F.,and E.Fliers.1985."A Sexually Dimorphic Nucleus in the Human Brain"Science 228: 1112-15. oSwaab,D.F.,andM.A.Hofman.1988."SexualDifferentiation oftheHumanHypothalamus:Ontogenyofthe SexuallyDimorphicNucleusof thePreoptic Area." Developmental BrllinResearch 44:314-18. Allen, Laura S.,Melissa Hines, James E.Shryne, and Roger A.Gorski.1989. "Two Sexually Dimorphic Cell Groups in the Human Brain." 10urnal of Neuroscience 9:497-506 LeVay, Simon.1991."Evidence foran Anatomical Difference in the Brains of Homosexual Men" Science 253:1034-37. MYTHSOFGENDER mission and ejaculation. The smallest decreaseswerein contact and mounting,thelargestinintromissionandejaculation.Onemale recoveredcompletely.Theoperatedmalesimprovedtheirperfor-mance on the lever-pressing tests, indicating their continued interest insocial-althoughnotnecessarilysexual-contact.Finally,the frequencyofmasturbationdidnotchange.LeVay'sinterpretation isthattheoperationimpairedheterosexualbehaviorbutnotsex drive. Let's examine the logic.First,one must accept that masturbation frequencymeasuressexdrive.Whilethatispossible,soaremany otherthings.Forexample,masturbationfrequencycouldmeasure boredom.Themalesinthisgrouphadbeenhousedforl.5to6.5 yearsinindividualcages,roughlysixteenfeetonallsides,ina roomcontainingonlyothermales.Nomentionismadeofthe provisionofenvironmentalstimuli.Second,onemustacceptthat anexperimentaldesignusingonlyheterosexualpairscouldade-quatelyaddresstheissueofsexualorientation.ThestudiesLeVay usestoframehisapproachcertainlyshowthatinmalemonkeys the hypothalamus isinvolvedin some manner in sexual performance, but theyhardly provideamodel fortheframingof questionsabout sexualorientation. Onefinalnoteaboutgenderdefinitions.Slimpandcoworkers notedthatmalemonkeysoftenpresentedtheirrumpstoother malesforexaminationandoccasionalmounting.Althoughthis behavior ispartofthenormalmalerepertoire,theydefineditasa femalesexualresponse,ratherthanasabehaviorcommontoboth sexes.Theyobservedthattheiroperatedmalespresentedtheir rumpsto(andweremountedby)femalesmoreoftenthandidthe controls(nodataorstatisticsareoffered)andsuggestthatthis mightrepresentII anincreasedtendencyofthemalestoassumea femalerole." Again the logicseems bizarre.Behaviors that occurin bothsexes(mountingandpresenting)areneverthelessdefinedas either male or female.Consequently, changes in these same behaviors become evidence of changesin masculinity andfemininity! Aftercitingtheaboveworktosuggestthatcertainregionsof thehypothalamusaffectmale-typicalbehaviorIwhatelsecould ejaculationandintromissionbe?),Dr.LeVaycontinuesbypointing out that men and women have dimorphic nuclei in their hypothalami. (Thisclaimisbasedonthedataintable8.5.)"Thus,thesetwo nucleicouldbeinvolvedinthegenerationofmale-typicalbehav-ior."27Definingmale-typicalbehaviorassexualorientationtoward 248 SEXANDTHESINGLEBRAIN women[andfemale-typicalasorientationtowardmen),LeVay hypothesizesthatINAH-3wouldbe"largeinindividualssexually oriented toward women [heterosexual men and homosexual women) and small in individuals sexually oriented toward men (heterosexual womenandhomosexualmen)./28Ignoringanextensiveliterature suggesting that both animaland human sexual behaviors are contin-uousratherthandichotomous,29LeVayteststhesecondhalfofhis hypothesis.Heneverclarifieshisanalogies.Doesheequatesexual orientationwithmountingandpresentingbehaviors?Ordoesit havesomethingtodowithsexualdrive,whichhehaslocatedin themasturbatory behaviorofrhesusmonkeys? TheLeVaystudyconfoundssexandgender.First,thebuilt-in assumptionisthatamale/femaledifferenceIf orexample,inthe hypothalamus)ought to bemirroredinthe gay/straight dichotomy. Thusgaymenarelikelytoresemblewomenphysiologicallyand lesbiansarelikelytoresemblemen.InTimeandScience,the reportsofhisresultsincludedaccountsofothersupposedsex differences-forexample,inspatialandmathematicalabilities. Thus discussionof sexhasbeenprofoundly confused with exchanges aboutgender:1o LeVay'sframeworkmakes theintricaciesof gender disappear.Humanbehavior,however,isfarmorecomplexthanhe admits.Howcanheexplainthefootballhero-masculinetothe core-who isnevertheless gay?And what about the highlyfeminine lesbian,thestraightmanwhofantasizesabou