The IQs of identical twins who were separated early in life and raised in different homes correlate almost as much as
A) half-siblings.
B) non-identical siblings.
C) identical twins raised together.
D) cousins.

Question

Quizplus · Accepted Answer

The correlation between the IQs of identical twins raised together is very high due to their genetic similarity, and the correlation between the IQs of identical twins raised apart is only slightly lower due to shared genes and similar prenatal environments. The correlations between half-siblings, non-identical siblings, and cousins will be even lower due to less genetic similarity and different environments.

The IQs of Identical Twins Who Were Separated Early in Life