If differences in heredity are important for differences in IQ scores,what should we expect to find?
A)IQ correlations should be equally high for monozygotic and dizygotic twins.
B)IQ correlations should be higher for dizygotic than monozygotic twins.
C)IQ correlations should be higher for monozygotic than dizygotic twins.
D)IQ correlations should be higher for twins reared apart than reared together.

Question

If differences in heredity are important for differences in IQ scores,what should we expect to find?
A)IQ correlations should be equally high for monozygotic and dizygotic twins.
B)​IQ correlations should be higher for dizygotic than monozygotic twins.
C)​IQ correlations should be higher for monozygotic than dizygotic twins.
D)​IQ correlations should be higher for twins reared apart than reared together.

Quizplus · Accepted Answer

If heredity is important for differences in IQ scores, we would expect that IQ correlations would be higher for monozygotic twins (who share all of their genes) than for dizygotic twins (who share only 50% of their genes on average). This is because any differences in IQ scores between monozygotic twins must be due to environmental factors, whereas differences in IQ scores between dizygotic twins could be due to genetic or environmental factors. Therefore, the fact that IQ correlations are higher for monozygotic twins than for dizygotic twins provides evidence that heredity is a factor in IQ differences.

If Differences in Heredity Are Important for Differences in IQ