Extensive investigations of the relationships of scores on intelligence tests to degree of kinship have found the highest correlation between the IQs of
A) fraternal twins reared apart.
B) fraternal twins reared together.
C) identical twins reared apart.
D) identical twins reared together.

Question

Quizplus · Accepted Answer

Identical twins reared together have the highest correlation between their IQ scores because they share both their genetic makeup and their environment, which are the two primary factors influencing intelligence.

Extensive Investigations of the Relationships of Scores on Intelligence Tests