Identical twins raised in the same homes have IQs correlated at about.86. Identical twins raised apart have IQs correlated at about.75. Unrelated adopted children raised in the same home have IQs correlated at about.32. Based on this information and research on the heritability of intelligence, we can say that ___________________ of the population variability in intelligence can be attributed to the environment.
A)between a quarter and a third
B)half
C)most
D)little than a quarter
E)more than half

Question

Quizplus · Accepted Answer

The correlation of IQs between identical twins raised apart (.75) compared to unrelated adopted children raised in the same home (.32) suggests that while genetics play a significant role in determining IQ, the environment also accounts for a portion of the variability. The difference in correlation indicates that the environment contributes to the variability in intelligence, but less than genetics. Therefore, stating that between a quarter and a third of the population variability in intelligence can be attributed to the environment is a reasonable conclusion based on the provided correlations.

Identical Twins Raised in the Same Homes Have IQs Correlated