When Comparing Samples of Middle-Class and Impoverished Twins, Researchers Have

Multiple Choice

When comparing samples of middle-class and impoverished twins, researchers have found that

A) genes influence behavior more greatly in the impoverished samples.
B) about 50% of the variations in middle-class twins was due to random chance
C) genes accounted for less than 10% of the IQ differences among impoverished twins
D) less than 40% of the IQ differences in middle-class twins was accounted for by genes