Science: A Touch of Heterosis

When a movie star is billed as having "it" or "oomph," what she probably has is heterosis (hybrid vigor). At least, that is what Geneticist George D. Snell says. In the current Quarterly Review of Biology, Snell assembles evidence to show that superior qualities in humans, including physical attractiveness, are often due to heterosis, resulting from the crossing of two strains.

Dr. Snell describes heterosis in the case of swine (Hampshires crossed with Duroc Jerseys produced superior pigs). Since he cannot repeat the same experiment with people, he sifts a great mass of records...