It is generally understood that inbreeding has some negative biological consequences for complex animals. But what, specifically, are the consequences of inbreeding for a trait such as intelligence. The scientific literature here is somewhat muddled. But it seems likely that all things equal if two people of average intelligence pair up and are first cousins the I.Q. of their offspring will be expected to be 0-5 points lower than would otherwise be the case.
But what about genetic homogeneity that’s not due to inbreeding?
Read the full article here: Genetic diversity and intellectual disability
