Behavior Geneticists Study the Concordance Rates of Monozygotic (MZ) and Dizygotic

Multiple Choice

Behavior geneticists study the concordance rates of monozygotic (MZ) and dizygotic (DZ) twins to estimate the environmental and genetic influences on behavior. Which of the following provides evidence for an environmental impact on behavior?

A) MZ concordance rates less than 100 percent
B) DZ concordance rates less than 100 percent
C) MZ concordance rates greater than DZ concordance rates
D) DZ concordance rates greater than MZ concordance rates