Kelly and Shelly are identical twins who have been raised apart, in separate adoptive homes. Shelly has developed a psychological disorder, but Kelly does not appear to have the same disorder. This information could be used as evidence to suggest that
A) genetic factors have more influence than environmental factors in this disorder.
B) environmental factors have more influence than genetic factors in this disorder.
C) both genetic and environmental factors contribute equally to this disorder.
D) neither genetic nor environmental factors contribute to this disorder.

Question

Quizplus · Accepted Answer

The fact that the identical twins, who have the same genetic makeup, were raised in different environments and only one has developed the disorder suggests that environmental factors have played a role in the development of the disorder. If genetic factors were solely responsible, then both twins would be expected to have the disorder. Therefore, option B is the best choice.

Kelly and Shelly Are Identical Twins Who Have Been Raised