Assortative marriage and the familiality of cognitive abilities in families of extremely gifted students

The top 1% of the extremely bright students identified by the Study of Mathematically Precocious Youth (Benbow & Stanley, 1980b) were tested along with their parents, using a battery of specifically designed cognitive tests. These students represented the top 0.03% of their age group in intellectual ability. The results showed that the parents were extremely able and resembled one another significantly more than parents in the general population. In addition, the intellectually precocious children resembled their parents to a lesser extent than children of average ability resemble their parents. These results suggest that considerable assortative mating has occurred among the parents of these extremely gifted youth, but that extreme giftedness cannot be predicted reliably solely as a result of the mating of bright parents.