In their study of the heritability of autistic traits among Dutch teens, Rosa Hoekstra and her colleagues were careful to choose participants from a variety of backgrounds and circumstances. Why is careful sampling especially important to studies of heritability?
A) The effects of heritability are most obvious in populations that exclude extreme environmental conditions, such as affluent or very poor families.
B) Environmental influences are magnified in extreme environmental conditions, such as among affluent or very poor families.
C) Extremes of environmental conditions, such as affluent or very poor families, tend to magnify the influence of heritability.
D) These precautions are really not relevant, because heritability cannot be assessed experimentally.