Adoption studies of intelligence suggest that:
A)Genetic factors are the sole determinant of intelligence
B)Family environment more strongly determines intelligence than genetics
C)Both genetics and environment contribute to intelligence
D)It is possible to rule out confounding factors and make reliable conclusions

Question

Quizplus · Accepted Answer

Adoption studies have shown that genetics and environment both contribute to the development of intelligence. This is because adopted children share no genetic material with their adoptive parents, but may share genetic material with their biological parents, yet are raised in a different environment. By studying adopted children, researchers can separate genetic and environmental influences on intelligence. In general, adoption studies suggest that genetics plays a larger role in determining intelligence than family environment, but that both factors contribute to intelligence. However, it is difficult to completely rule out confounding factors in adoption studies, such as the possibility that adopted children are placed in homes similar to their biological families in terms of socio-economic status, or that children in similar situations are more likely to be put up for adoption in the first place.

Adoption Studies of Intelligence Suggest That