Intelligence and educational attainment — practice questions

IQ argument: Herrnstein & Murray — hereditary ability predicts success; meritocratic selection.

Sociological counter: Labelling (Becker, Rosenthal & Jacobson) shapes outcomes independent of ability; streaming traps pupils; cultural/material deprivation affects performance; IQ tests culturally biased.

Middle position: Some cognitive differences exist but small compared to social factors; test performance ≠ innate intelligence.

Evaluation: Attainment gaps follow class/ethnic/gender patterns too neatly for biology alone — social structures better explain.

Conclusion: Intelligence plays a role but not main cause of inequality.

Step 1: Calculation

• Formula: h² = 2 * (rMZT - rDZT)
• Substitute values: h² = 2 * (0.86 - 0.60)
• Calculate difference: h² = 2 * (0.26)
• Final result: h² = 0.52

Interpretation: The heritability estimate is 0.52. This suggests that 52% of the variation in IQ in the studied population is attributable to genetic factors.

Step 2: Sociological Criticisms

• Criticism 1: The Equal Environments Assumption. This method assumes that identical (MZ) and non-identical (DZ) twins experience equally similar environments. Sociologists argue this is flawed because MZ twins' identical appearance means they are often treated more similarly by parents and teachers than DZ twins. This greater environmental similarity, not just genetics, could inflate the MZ correlation and the final heritability estimate.
• Criticism 2: Ignores Macro-Environmental Factors. Heritability estimates are population-specific and cannot explain changes over time. The Flynn Effect shows that average IQ scores have risen significantly over generations, a change too rapid to be genetic. This points to the powerful influence of societal-level factors like improved nutrition and schooling, which this type of calculation does not account for. It mistakes a statistical correlation for a fixed biological law.