Intelligence Testing

Intelligence Testing

March 8, 2006Pauline Yu and Neha Begwani

March 8, 2006Pauline Yu and Neha Begwani

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HistoryHistory

“I advance it, therefore, as a suspicion only, that the blacks, whether originally a distinct race, or made distinct by time and circumstance, are interior to the whites in he endowment both of body and of mind.” Thomas Jefferson

“I advance it, therefore, as a suspicion only, that the blacks, whether originally a distinct race, or made distinct by time and circumstance, are interior to the whites in he endowment both of body and of mind.” Thomas Jefferson

CraniometryCraniometry

George MortonHypothesis: “objectively by physical characteristics of the brain, particularly by its size.”

Approximate intelligence by measuring the volume of the cranium

Large sources of bias in methodology

George MortonHypothesis: “objectively by physical characteristics of the brain, particularly by its size.”

Approximate intelligence by measuring the volume of the cranium

Large sources of bias in methodology

Morton’s ResultsMorton’s ResultsRace Number of

ObservationsMean Largest Smallest

Caucasian 52 87 109 75

Asian 10 83 93 69

Polynesian 18 81 89 64

Native American

147 82 100 60

African 29 78 94 65

Brain Size as Proxy for Intelligence

Brain Size as Proxy for Intelligence

Correlation between body size and cranium size“This fact does not imply that big people are smarter—any more than elephants should be judged more intelligent than humans because their brains are larger.” (Gould, 61)

Correlation between body size and cranium size“This fact does not imply that big people are smarter—any more than elephants should be judged more intelligent than humans because their brains are larger.” (Gould, 61)

Bias in Sample SizeBias in Sample Size

Morton’s experimentation suffered from disproportionate sample size Unequal representation of subgroups within a race group

Native American sample25% was the smaller brained Inca Peruvians

2% was the larger brained Iroquois

Morton’s experimentation suffered from disproportionate sample size Unequal representation of subgroups within a race group

Native American sample25% was the smaller brained Inca Peruvians

2% was the larger brained Iroquois

Morton’s Subconscious Morton’s Subconscious

Bias from subconscious belief in superiority of white racePacking the craniums of white subjects as tightly as possible

Did not put same effort for Black and Native American Races

Rounded results to further skew data

Bias from subconscious belief in superiority of white racePacking the craniums of white subjects as tightly as possible

Did not put same effort for Black and Native American Races

Rounded results to further skew data

Racial ComparisonsRacial Comparisons

Paul Broca (1824-1880) compared the

radius:humerus ratios in humans

(larger ratio = longer forearm)

Apes have long forearms

Paul Broca (1824-1880) compared the

radius:humerus ratios in humans

(larger ratio = longer forearm)

Apes have long forearms

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RatiosRatiosWhites - 0.739Blacks - 0.794

But…..Eskimos - 0.703Native Americans - 0.709

Whites - 0.739Blacks - 0.794

But…..Eskimos - 0.703Native Americans - 0.709

•Broca concluded: “After this, it seems difficult to say that elongation of the forearm is a character of degradation or inferiority”

Stanford-Binet Test

Stanford-Binet Test

Sample Questions (1911 Version):An Indian who had come to town for the 1st time in his life saw a white man riding across the street. As the white man rode by, the Indian said - “The white man is lazy; he walks sitting down.” What was the white man riding on that caused the Indian to say, “He walks sitting down.”

My neighbor has been having queer visitors. First a doctor came into the house, then a lawyer, then a minister. What do you think happened there?

Sample Questions (1911 Version):An Indian who had come to town for the 1st time in his life saw a white man riding across the street. As the white man rode by, the Indian said - “The white man is lazy; he walks sitting down.” What was the white man riding on that caused the Indian to say, “He walks sitting down.”

My neighbor has been having queer visitors. First a doctor came into the house, then a lawyer, then a minister. What do you think happened there?

Catherine CoxCatherine CoxAttempted to estimate the IQs of 282 geniuses

Flawed and illogical but… from this study she earned a PhD from Stanford!

Attempted to estimate the IQs of 282 geniuses

Flawed and illogical but… from this study she earned a PhD from Stanford!

Some of her results:

Average A1 IQ (birth-17) - 135

Average A2 IQ (17-24) - 145

Major flaw - IQ is not supposed to alter with age.

“Normal” IQ Range: 85-115

Yerkes and the Army ExamsYerkes and the Army Exams

“Examinations Alpha and Beta are so constructed and administered as to minimize the handicap of men who because of foreign birth or lack of education are little skilled in the use of English. These group examinations were originally intended and are now definitely known to measure native intellectual ability.” - Yerkes

“Examinations Alpha and Beta are so constructed and administered as to minimize the handicap of men who because of foreign birth or lack of education are little skilled in the use of English. These group examinations were originally intended and are now definitely known to measure native intellectual ability.” - Yerkes

Army Examination (Alpha)Army Examination (Alpha) The most prominent industry in Detroit is (A) automobiles (B) brewing (C) flour (D) packing

Velvet Joe appears in advertisements for (A) tooth powder (B) dry goods (C) tobacco (D) soap

The most prominent industry in Detroit is (A) automobiles (B) brewing (C) flour (D) packing

Velvet Joe appears in advertisements for (A) tooth powder (B) dry goods (C) tobacco (D) soap

Results:

Average mental age of white American adults stood at 13!

European immigrants: Russian - 11.34, Italian -11.01, Pole - 10.74

IQ = (Mental Age / Actual Age) X 100

IQ Testing TodayIQ Testing Today

Major Cultural Biases in Testing:Non-verbal Raven’s test vs. highly verbal Peabody Picture test

BITCH test developed to counter the cultural differences

Major Cultural Biases in Testing:Non-verbal Raven’s test vs. highly verbal Peabody Picture test

BITCH test developed to counter the cultural differences