If adopted children resemble their biological parents on a specific trait (even though they were not raised by them), it is likely that genetic factors influence that trait. Conversely, if adopted children resemble their adoptive parents (even though they don't share any of the same genes), it is likely that environmental factors influence the trait. Adoption studies assessing intelligence have indicated that there is a significant correlation (.36) between adopted children and their biological parents, suggesting a genetic influence. However, there is also a significant, slightly lower correlation (.31) between adopted children and their adoptive parents. It can therefore be concluded that intelligence is influenced by both heredity and the environment.