Suppose that researchers estimate that broad-sense heritability of IQ in Sweden is 0.8.Which of the following conclusions is valid, assuming that the estimate is accurate?
A)Most variance for IQ in Sweden is due to total genetic variance.
B)In Sweden, the environment does not play a large role in determining the IQ of individuals.
C)Enriching the environment of poor children in Sweden would not lead to a big improvement on IQ tests.
D)Broad-sense heritability of IQ in the United States probably is close to 0.8.
E)If another country has a lower broad-sense heritability for IQ, then this difference must be genetically based.

Question

Quizplus · Accepted Answer

Broad-sense heritability (H^2) is defined as the proportion of total phenotypic variance that can be explained by genetic variance. Therefore, a heritability estimate of 0.8 suggests that 80% of the variation in IQ within the Swedish population is due to genetic differences. This means that genetic factors are the main contributor to IQ differences in Sweden, which supports option A. However, it does not necessarily mean that environmental factors are unimportant or that interventions to improve the environment could not lead to an increase in IQ. Option B and C are therefore incorrect. Option D is also incorrect because the heritability of IQ in the United States could be different from Sweden, and there is no reason to assume they are the same. Option E is also incorrect because a lower heritability in another country could reflect differences in environmental factors, not just genetic factors.

Suppose That Researchers Estimate That Broad-Sense Heritability of IQ in Sweden