asks Sharon Begley in Newsweek:
Why isn’t everyone beautiful, smart and healthy? Or, in a less-polite formulation, why haven’t ugly, stupid, unhealthy people been bred out of the population—ugly people because no one will have them as mates, meaning they don’t get the chance to pass their ugliness to the next generation;
Evolutionary geneticists try to explain this paradox by positing that mutations for disadvantageous traits keep popping up no matter how hard natural selection attempts to wipe them out, but in their more honest moments the scientists admit that in real life undesirable traits are way more common than this mechanism would account for; “ugly” mutations just don’t occur that often. In a groundbreaking study, biologists at the
The scientists studied
The reason is that any particular gene-based trait may have very different effects on males than in females. Extrapolating to humans (and oversimplifying, sorry) you might imagine that a particular shape of the nose or turn of the chin would look drop-dead hunky on a male, but horsey on a woman; dad got to mate because his looks attracted a female, but the result of their togetherness produced daughters whose pulchritude was less than obvious.
Do we see this in humans or not? It would seem like the kind of thing there would be some folk wisdom about, but I've never heard any.
A lot of good looks is just non-sex specific all-around healthiness. Mark Harmon, who remains a popular TV actor in his mid-50s ("NCIS") due to his handsomeness, is a good example of all-aroundness. Before going into acting, he was a fine Wishbone running quarterback despite being not particularly big. In his first game for UCLA in 1972, he led a famous upset of mighty
On the other hand, there may be some sex-specific good looks. I know a family with a handsome, strong-jawed manly son and a handsome strong-jawed manly daughter, so perhaps so.
On the other other hand, Warren Beatty and Shirley MacLaine are full siblings. In their younger days, they were both very good looking exemplars of their sexes, with Shirley tending toward the very girly pixieish side. On the other other other hand, Jane Fonda inherited a little too much of her father's All-American good looks. She's a very healthy woman, but nobody would confuse her with Audrey Hepburn for exquisiteness. John Cusack, with his unfortunate Cupid's bow lips, might be prettier than his sister Joan. Jon Voight had big lips for a leading man, which his daughter Angelina Jolie inherited to her advantage.
The three generations of Hustons who won Oscars started with the the conventionally handsome Walter, followed by director/actor John Huston, who was ultra-masculine but not particularly good looking (he had kind of the John Kerry-Herman Munster thing going -- here are the two together), followed by Angelica Huston, who took a little too much after her father in looks, but even though she wasn't conventionally pretty was woman enough to keep Jack Nicholson around for years.
Perhaps one way to test this is to see if pairs of sibling movie stars or parent-child pairs are less likely to be opposite sex than would be randomly expected. I suspect that may be true, although that may stem more from same-sex siblings (e.g., Luke and Owen Wilson) hanging out together more than opposite sex siblings spend time together.
Anyway, there are various genetic mechanism that could theoretically be at work. For example, consider the jaw. Having a big square jaw helps make, say, Christopher Reeve of Superman fame looking like a really handsome guy and having a petite jaw helps make Audrey Hepburn look like a really pretty girl.
- Now you could have a big square jaw because you inherited some big square jaw genes regardless of sex, so the men in your family would tend to be handsome and the women horse-faced.
- Or you could inherit some genes that set the average level of sex hormones relative to your sex above or below average. Once again, you'd see the same effect.
- Or you could inherit some genes that say, "Have more than the average level of male hormones if you are male and more than the average level of female hormones if you are female." You could call this the Beatty-MacLaine syndrome.
- Or, there could be lots other combinations, including more of both sexes' hormones than is typical for your sex (which might be more common than average in celebrities, such as David Bowie or Marelene Dietrich.).