Le texte dans son contexte : l’enjeu de l’eugénisme · Le texte dans son contexte : l’enjeu...

Letextedanssoncontexte:l’enjeudel’eugénisme

LucBerlivetCERMES3CNRS/EHESS

Atelier:UnsiècledeFisherJeudi12etvendredi13septembre2019

IntroductionThis image cannot currently be displayed.

L’eugénisme britannique… pardon,anglais

… pasqu’unesimplequestiond’airdutemps

Biométriciensvs.Mendéliens

KarlPearson &FrancisGalton(1909) ReginaldPunnett &WilliamBateson(1908)

RonaldA.Fisher(1890-1962)

ÉtudiantàCambridge(CaiusCollege)1908-1912,grâceàune"scholarship"

LitMendel… etPeason

Reçuavecmention(Wrangler)

Une "oneyear Studenship"(1912-1913)luipermetdeseperfectionnerenmécaniquestatistique,auprèsdeJamesJeans,etenprobabilités(theory oferrors)auprèsdeF.J.M.Stratton.

MembrefondateurdelaCambridge Eugenics Societyàl’université

R.A.Fisher,“Theevolution ofsexual preference.”TheEugenicsreview vol.7,3(1915):184-92

MajorLeonardDarwin(1850-1943)

LeonardDarwin“Heredity andenvironment:Awarningtoeugenists.”TheEugenics review vol.8,2(1916):93-122.

Evaluationsdelapropositiond’articledeFisherPearson’s report on Fisher’s paper (1916)"The author adopts a special hypothesis for determining thesomatic character o f an individual dropping the Mendelianphenomenon of dominance. It appears to me that hishypothesis is only one of a very large number that would leadto similar results, and it is not supported by any observationalor experimental evidence that could differentiate it from them.[…]I do not think in the present state of affairs that the paper iswide enough to be of much interest from the biometricstandpoint for its hypotheses need some observational basis. Ifpublished the author should indicate the exact stage in hisanalysis where he supposes Snow (and Jacobs S. Proc. Vol. 84 Bpp. 23-42) to have gone wrong in their treatment of cousins,rather than by asserting (although their results are confirmedby observation) that they must be in error, because their resultsdiffer from his. Whether the paper be published or not shoulddepend on Mendelian opinion as to the correspondence of theauthor’s hypotheses with observation, and the probability thatMendelians will accept in the near future a multiplicity ofindependent units not exhibiting dominance or coupling."

Punnett’s reportonFisher’s paper (1916)

"IhavehadanothergoatthispaperbutfranklyIdonotfollowitowingtomyignoranceofmathematics.

[…]Andasacontributiontobiometryitmayhavearealvalue—butIamnotqualifiedtojudgeitfromthatpointofview.However,whateveritsvaluefromthestandpointofstatistics&populationIdonotfeelthatthiskindofworkaffectsusbiologistsmuchatpresent.Itistoomuchoftheorderofproblemthatdealswithweightlesselephantsuponfrictionlesssurfaces,whereatthesametimewearelargelyignorantoftheotherpropertiesofthesaidelephantsandsurfaces."

Pearson’s reportonFisher’s paper (1916)

"The author adopts a special hypothesis for determining the somatic character o f anindividual dropping the Mendelian phenomenon of dominance. It appears to me that hishypothesis is only one of a very large number that would lead to similar results, and it isnot supported by any observational or experimental evidence that could differentiate itfrom them. […]I do not think in the present state of affairs that the paper is wide enough to be of muchinterest from the biometric standpoint for its hypotheses need some observational basis. Ifpublished the author should indicate the exact stage in his analysis where he supposesSnow (and Jacobs S. Proc. Vol. 84 B pp. 23-42) to have gone wrong in their treatment ofcousins, rather than by asserting (although their results are confirmed by observation) thatthey must be in error, because their results differ from his. Whether the paper bepublished or not should depend on Mendelian opinion as to the correspondence of theauthor’s hypotheses with observation, and the probability that Mendelians will accept inthe near future a multiplicity of independent units not exhibiting dominance or coupling."

Punnett’s reportonFisher’s paper (1916)Lettre à (G.H.?)Hardydu8aôut 1916

"IhavehadanothergoatthispaperbutfranklyIdonotfollowitowingtomyignoranceofmathematics.[…]Andasacontributiontobiometryitmayhavearealvalue—butIamnotqualifiedtojudgeitfromthatpointofview.However,whateveritsvaluefromthestandpointofstatistics&populationIdonotfeelthatthiskindofworkaffectsusbiologistsmuchatpresent.Itistoomuchoftheorderofproblemthatdealswithweightlesselephantsuponfrictionlesssurfaces,whereatthesametimewearelargelyignorantoftheotherpropertiesofthesaidelephantsandsurfaces."

L’engagementeugéniquedeFisheraprès1919

• MembreactifduResearch Committee delaEugenics SocietyofLondon(recrééen1923)• Rejointleconseildedirectiondel’association• Endevientvice-président• AprèssonarrivéeàUCL(1933)tissedesliensentrelaEugenics SocietyetleGaltonLaboratory (initialementenfroid)

ØSubventionàlapublicationdesAnnals ofEugenics (fondéesparK.P.- 1925)• TensionscroissantesavecC.P.Blacker (secrétairegénéraldel’association)• DemeureVice-Présidentjusqu’en1937• Quittefinalementleconseildedirectionen1942

Lacritiqueanti-eugéniquedestravauxdeFishersurlepoidsdel’hérédité• LancelotHogben 1895-1975• Zoologueetgénéticien• Enseignant‘itinérant’:Edinburgh,McGill,CapeTown,LondonSchool ofEconomics,University ofAberdeen,University ofBirmingham,War Office(1944-1946)…• Vulgarisateurscientifiqueàtrèsgrandsuccès(mathematics forthemillion)• Socialisteenluttecontreledéterminismebiologique• 1933:publieNatureandNurture (WilliamWithering Memorial Lectures)Ø CritiqueradicaledesthèsesdeFisher– nourriedeseséchangesaveccedernier(cf.travauxdeJamesTabery)

Hogben àFisher,23février1933(citédansJamesTabery – 2008):commenceparpréciserquelepointqu’ilsouhaitediscuteravecFisher‘concerns aninherent relativity intheconceptofnatureandnurture’…“ThepointIam after is notwhat assumptions aboutthedistributionoftheenvironment andthedistributionofgene differences aremadeinthemathematical formulationoftheproblem.Obviously we can makemoreorless arbitrary assumptions aboutthat.What Iam worriedaboutis amoreintimate sense inwhich differences ofgeneticconstitutionarerelated totheexternal situationintheprocess ofdevelopment.”

‘Ifdifferences ofnurture were distributed uniformly within thefamilyunitandbetween onefamily unitandanother,theconceptofancestrywould involve noambiguity inhuman genetics.Inthelaboratory wecan culturestocksofoviparous animals,arranging theconditionsso astoensurf that any slight differences towhich different individuals areexposed areaslikely toinvolve two related individuals astoinvolve twounrelated individuals.Then andthen only arewe safe,when we speakof“therandom external effects ofenvironment”anddealwith natureandnurture asindependent variables.Infact this conditionis notstrictly realised when we arestudying aviviparous animal.Afurthercomplicationariseswhen we aredealing with socialspecies like theprimates,which liveinfamily groups’L.Hogben,NatureandNurture…,1933,p.109

‘Hence theancestry ofanindividual,that is tosay what he shares withorderives from his ancestors,includes:(i) asystemofgenetic relations(ii) asystemofdevelopmental relationships determined bytheuterine

environment butcorrelated with thepreceding,and(iii) aframework ofsocialandphysical environment also related tothe

genetic ‘‘ancestral’relationship.’

L.Hogben,NatureandNurture…,1933,p.110

"Dear Hogben,Ithink Isee your pointnow.Youareonthequestionofnon-linear interactionofenvironment andheredity.Theanalysis ofvarianceandcovarianceis only aquadratic analysis andassuch only considers additiveeffects.Academically onecould proceed intheory,though inatheory notyetdeveloped,tocorresponding analysesofthethird andhigher degrees.Practically it would be very difficult tofind acaseforwhich this would be oftheleastuse,asexceptional typesofinteractionarebesttreated ontheirmerits,andmany become additiveorso nearly so astocausenotroublewhen you choose amoreappropriate metric.Thus facet number showsitssweet reasonableness when measured in‘proportional units’orinotherwords onalogarithmic scale.However perhaps themainpointis that youareunder noobligationtoanalysevarianceinto partsifit does notcomeapart easily,andits unwillingness todoso naturally indicates that one’s lineofapproach is notvery fruitful"

R.FisheràL.Hogben,25février1933 - citédansJ.H.Bennett,Naturalselection,heredity,andeugenics,1983,p.218

AprèslaDeuxièmeGuerremondiale,ConradWaddington(1957)reprendraenpartiel’argumentationdeHogbenØTheStrategy oftheGenes,Londres,GeorgeAllen&Unwin,1957

Conclusion

Laquestionde"l’influencedesthèseseugénistes"surFisher:leslimitesd’uneanalyseentermed’imprégnationparl’airdutemps

L’antienne"Tousn’étaient-ilspaseugénistes? »masquelesspécificitésdel’engagementdeFisher…… quidoiventimpérativementêtreprisesencomptelorsquel’onlitl’articlede1918!

Mercidevotreattention…