In research using the twin method,a disorder is heritable if the concordance is __________ in DZ compared to MZ twins is
A)absent.
B)higher.
C)the same.
D)lower.

Question

Quizplus · Accepted Answer

The correct choice is D as a disorder is considered heritable if the concordance rate is lower in DZ twins compared to MZ twins. This is because MZ twins share 100% of their genes, while DZ twins share only 50%, which allows researchers to estimate the relative contribution of genetics and environment to the development of the disorder. If the disorder is heritable, the concordance rate (i.e., the proportion of twin pairs in which both twins have the disorder) should be higher in MZ twins than in DZ twins. Conversely, if the disorder is not heritable, the concordance rate should be similar in both MZ and DZ twins.

In Research Using the Twin Method,a Disorder Is Heritable If