Over the last century, there has been a great deal of discussion and research that has tried to determine the relative influence of nature and of nurture on intelligence. The consensus today is that both make a strong contribution. What is one piece of evidence showing that nature (genetics) makes a contribution and one showing the influence of nurture (environment)?
1. What is one piece of evidence showing that nature (genetics) makes a contribution and one showing the influence of nurture (environment)?
Twin studies of identical twins shows that identical twins have similar intelligence levels even when reared apart. This is the same in adoptee studies, where the adopted children have similar IQs as their biological parents, and not their adopted parents, which adds evidence to the nature side of the controversy. In fact, the hypothesis of the heritability of IQ has now been tested - on twins and adoptees, and every study has found a certain and often substantial heritability. ...
This posting offers help with assessing nature vs nurture. References are also provided to justify the assertions.