A shift in the beauty standard, Baby Jane
Hottie parents are more likely to have a daughter (for their first child) than a son, a London School of Economics report says. It's likely, though not stated in the media report, that the gender of a 2nd child is influenced by the gender of the already-present first child.
The evolutionary logic? Women are more likely to benefit from physical beauty; the reproductive success of men depends in part on the status of their father, and the reproductive success of women depends partially on their physical attractiveness. (as well as signs of youthfulness.)
The question remains: how do reproductive processes "know" that the parents are attractive? What signs of beauty are able to trickle down from the mind of the person who's always been told they're hot, who has always enjoyed high status, from their ego to their Fallopian tubes or seminal vesicles? I mean, that's what has to happen, right?