The correlation between IQ scores of identical twins raised together is found to be +.85 and the correlation between IQ scores of identical twins reared apart is found to be +.70.What is the most likely source of the .15 difference found between the two groups?
A)the impact of genetics.
B)the impact of the environment.
C)sampling errors.
D)validity of the assessment tool.

Question

Quizplus · Accepted Answer

The .15 difference in correlation between identical twins raised together and those raised apart suggests that environmental factors may have played a role in their IQ scores. If genetics were the only factor, we would expect the correlations to be identical for both groups. Sampling errors and validity of the assessment tool are less likely explanations for the observed difference.

The Correlation Between IQ Scores of Identical Twins Raised Together