Day 130 MCAT Practice Question

Answer A is correct

Twin studies are experiments in which identical twins (two individuals with the exact

same genetic makeup) are raised in different environments and under different parental

influences, then studied to evaluate how different “nurture” conditions influenced

them. The main benefit of twin studies is found in the fact that the “nature” conditions

(e.g. the genetic predispositions of the participants) can be assumed to be the same.

Twin studies are not meant to differentiate the impact of parental influences from

environmental factors, as parental influences and environmental factors are closely

linked and are not separated out in twin studies. Instead, twin studies are meant to

separate the combined influences of parental and environmental factors from genetic

ones as a means of exploring the “nature vs. nurture” controversy–in other words, how

much of a person’s behavior can be attributed to nature (or genes), and how much can

be attributed to nurture (which includes both parental influences and environmental

factors). For this reason, Answer A is correct.