The Bell Curve Flashcards

What is the main topic of Chapter 13 of The Bell Curve?

Ethnic differences in measured cognitive ability (IQ) in the United States.

Which five ethnic groups are primarily discussed?

Whites, Blacks, Latinos, East Asians, and Jews.

What is the authors’ central research question?

Whether group IQ differences stem from genetics, environment, or both.

Do the authors emphasize group or individual differences more?

Individual differences; group averages should not define individuals.

What type of approach do the authors claim to use?

Empirical and statistical, not moral or political.

How do they characterize IQ distributions among groups?

All are normally distributed with different means but similar shapes.

What is the mean IQ for the total U.S. population?

100, with a standard deviation of 15.

What do the authors warn about when discussing group averages?

They should not be used to justify prejudice or policy discrimination.

What long-term stability is noted regarding IQ gaps?

Gaps have persisted for decades despite societal changes.

What kind of evidence do they rely on to discuss IQ differences?

Standardized psychometric test results such as WAIS, SAT, and AFQT.

What is the average White–Black IQ difference?

About 15 points (one standard deviation).

Has this gap narrowed substantially over the 20th century?

No; it has remained relatively constant.

On which subtests is the gap largest?

Abstract reasoning and problem-solving.

On which subtests is it smallest?

Rote memory or concrete information tests.

What proportion of Black individuals score above the White mean?

Roughly 16 percent.

What proportion of Whites score below the Black mean?

Roughly 16 percent.

What early-life evidence supports the stability of the gap?

Differences appear by early childhood and remain into adulthood.

Does the gap vary by socioeconomic class?

It persists within every SES level.

Are Black–White score differences larger on culturally loaded or culture-fair tests?

Similar on both; culture-fair tests show nearly the same gap.

What is the approximate percentile difference represented by 15 IQ points?

About the 84th percentile vs. 50th percentile.

Which test is cited as showing a consistent Black–White gap since WWII?

The Armed Forces Qualification Test (AFQT).

What happens to the gap when adjusting for income and education?

It decreases slightly but remains substantial.

Do the authors claim the gap reflects test bias?

No; they argue modern tests are not biased in predictive validity.

What type of reasoning shows the greatest mean difference?

Nonverbal and analytical reasoning.

Is the distribution overlap between groups large or small?

Large—indicating extensive individual overlap.

What is the average Latino IQ range?

Approximately 91 to 94.

Which subgroups are closer to 90?

Mexican Americans and Puerto Ricans.

Which subgroup scores closer to 100?

Cuban Americans.

What environmental factor most affects Latino IQ scores?

Degree of acculturation and English proficiency.

How do second-generation immigrants compare to first-generation?

They score higher, suggesting environmental improvement.

Do SES differences fully explain Latino–White score gaps?

No, though they contribute.

Are bilingualism and test language important variables?

Yes; test performance improves with English fluency.

What trend is observed with schooling duration among Latinos?

More years of education correlate with higher IQ scores.

What does variation among subgroups suggest?

Cultural and environmental diversity within “Latino” populations.

What is the general rank order: Blacks, Latinos, Whites?

Blacks < Latinos < Whites on average IQ.

What is the average East Asian IQ?

About 103.

Which cognitive domain is their strongest?

Spatial and nonverbal reasoning.

Which domain is slightly weaker relative to others?

Verbal reasoning.

Is this pattern seen inside and outside the U.S.?

Yes, both U.S.-born and Asian-born groups show it.

How do the authors interpret cross-cultural consistency?

As evidence IQ tests tap universal cognitive processes.

What possible explanations are offered for high Asian IQ?

Genetic, educational, and cultural influences combined.

Do East Asian test results contradict the idea of cultural bias?

Yes, because they outperform Whites despite different cultures.

What real-world outcomes align with East Asian IQ profiles?

High academic achievement and STEM representation.

How do East Asians perform in verbal creativity tests?

Slightly below Whites on average.

What conclusion is drawn about overall Asian ability?

Comparable or higher mean IQ with a distinctive cognitive pattern.

What is the mean Jewish IQ reported?

Approximately 112.

In which domain do Jews particularly excel?

Verbal and analytical reasoning.

Which type of occupational field reflects this strength?

Law, medicine, academia, and literature.

Did high Jewish IQ scores predate modern testing?

Yes; achievements were noted before standardized tests existed.

How do authors treat genetic explanations for Jewish IQ?

With caution; plausible but unproven.

Do Jews show uniformly high scores across all subtests?

No, verbal > spatial.

What cultural factors may enhance verbal performance?

Emphasis on reading, debate, and scholarship.

What percentile roughly corresponds to IQ 112?

Around the 79th percentile.

How do Jewish means compare to Asian means?

Higher overall, especially in verbal ability.

What do the authors caution about interpreting these data?

High means should not imply moral or social superiority.

What claim do authors make about test bias?

Modern IQ tests are not racially biased in predictive validity.

What does “predictive validity” mean?

The accuracy with which a test forecasts real-world performance.

What would biased tests show if they were unfair to minorities?

They would underpredict minority success.

Do IQ tests underpredict minority performance?

No; they predict equally for all groups.

How do item analyses address cultural bias?

By checking which questions show differential item functioning.

What do consistent cross-group results indicate about test construction?

That tests measure general intelligence rather than cultural trivia.

Are nonverbal tests less biased than verbal ones?

They show similar validity, suggesting minimal bias overall.

What is the “Flynn effect”?

Rising IQ scores over decades across populations.

Does the Flynn effect erase the Black–White gap?

No; both groups rise roughly in parallel.

How do the authors separate test bias from real group differences?

By comparing predictive validity and differential item analyses.

How much of the Black–White IQ gap does SES explain?

Roughly half.

Why can’t SES fully explain group gaps?

SES is partly a consequence of parental IQ.

What is the effect of school quality on IQ?

Improves scores modestly, not enough to close the gap.

What happens to early educational-program gains over time?

They often fade by adolescence.

What family factors correlate with higher IQ?

Parental stimulation, expectations, and stability.

Do within-family differences predict long-term IQ strongly?

Less strongly than genetic factors after childhood.

What cultural attitudes may influence achievement?

Valuing education, effort, and delayed gratification.

How might discrimination affect IQ performance indirectly?What is meant by “cultural mistrust”?

By limiting opportunities and motivation.

What is meant by “cultural mistrust”?

Suspicion of mainstream institutions that may depress test effort.

How do the authors evaluate environment-only explanations?

As insufficient to explain persistent mean differences.

What is the relation between nutrition and IQ differences?

Poor nutrition lowers IQ but doesn’t account for long-term group gaps.

What evidence supports environmental impact early in life?

IQ improvements with adoption or enriched early care.

Do those environmental gains persist fully into adulthood?

Usually diminish but not disappear.

What does the authors’ analysis suggest about SES policy effects?

Policies improve conditions but not equality of outcomes.

What do they mean by reciprocal causation between SES and IQ?

High IQ raises SES, which in turn enhances IQ development.

Do the authors assert genetics as the main cause of group gaps?

No, they call it plausible but unproven.

What type of studies support heritability within populations?

Twin and adoption studies.

What is the heritability estimate for IQ in adults?

About 0.6 to 0.8.

What key distinction do they stress regarding heritability?

Within-group heritability ≠ between-group causation.

What evidence comes from cross-racial adoption studies?

Black or mixed-race adoptees score between White and Black means.

How do these adoption results change over time?

Gains in childhood often lessen in adolescence.

What role do gene–environment interactions play?

They make clear separation of causes impossible.

What is meant by “plausible but unquantified” genetic influence?

There may be genetic contribution, but data cannot assign percentages.

How do the authors propose to approach this sensitive topic?

With empirical caution and rejection of moral judgment.

Why do they reject purely environmental determinism?

It fails to explain persistence and cross-national similarity of gaps.

How should policy address cognitive differences, according to the authors?

Focus on individual ability and opportunity.

What do they mean by “equality of opportunity vs. equality of outcome”?

Provide fair chances but not guarantee identical results.

What danger arises from ignoring real cognitive variation?

Ineffective or unrealistic social policies.

What danger arises from overemphasizing group averages?

Prejudice and misuse of statistics.

Do the authors link IQ to moral worth?

No, they explicitly reject moral evaluation.

How do they describe the social sensitivity of this topic?

As “emotionally and politically charged.”

What is their stance on data transparency?

Debate should rely on open, replicable data.

How can recognizing diversity aid policy design?

By tailoring education and training to varied abilities.

What is the final summary statement of the chapter?

Ethnic IQ differences exist statistically, but their causes are unresolved.

What overarching theme unites this chapter with the book’s thesis?

Cognitive ability strongly predicts life outcomes and varies across groups, influencing social structure.