Your text reports that the correlation between identical twins' scores on aggression measures is about .43; the correlation between fraternal twins' scores on aggression measures is around .14. Most immediately, these coefficients indicate:
A)a sizeable genetic contribution to aggression
B)a minor genetic contribution to aggression
C)a minimal role for shared environmental factors in aggression
D)both A and C

Question

Quizplus · Accepted Answer

The higher correlation in identical twins (who share 100% of their genes) compared to fraternal twins (who share about 50% of their genes) suggests a significant genetic contribution to aggression (A). The much lower correlation in fraternal twins also suggests that shared environmental factors play a minimal role, as both types of twins share their environments similarly (C).

Your Text Reports That the Correlation Between Identical Twins' Scores