Quite a bit of the evidence that's presented on here regarding physical attractiveness comes from the world of online dating. It's relatively easy online to aggregate ratings, messages, and other measures of attraction, and it's relatively hard to measure similar behaviors in a representative real-life setting. The constant critique of this data, though, is that the online dating world is filled with unattractive people (mostly men) who are only there because they can't get a date anywhere else -- the claim is that it's not representative.

I don't think this is the case. Consider that:

  1. Physically attractive people are generally more successful at dating
  2. Adults are busy
  3. It's easier to interact with 100 potential partners online than it is to interact with 100 potential partners in person
  4. People will generally do easy things that benefit them
  5. People will generally avoid hard things that don't benefit them
  6. As the size of a sample nears 100% of the total population, that sample becomes more likely to be representative of the total population

These are assumptions -- I'm not backing them up with evidence (although I'm pretty sure the fourth is mathematically valid) -- but they're assumptions on the level of "taller people are generally better at basketball." There's enough rationale behind them that it's reasonable to believe these over the null hypothesis.

If we assume (1) and (2), it stands to reason that plenty of attractive people are busy. Because (4) people do easy things that benefit them and (3) it's easier to meet a lot of potential partners online than it is in person, many of these attractive people are drawn to online dating. Once they're there, they find success (1) and therefore they stay (4). On the flipside, unattractive people gravitate to online dating because dating in the real world is hard for them (1 and 5), but then they don't always stay because online dating is hard for them, too (1 and 5). So while online dating is initially appealing to unattractive people they soon find out it's still tough and don't stick with it, and at the same time it's initially even more appealing to attractive people and they're liable to stay because they are able to find partners; neither of these factors is overpowering. Finally, online dating has become so common -- 15% of U.S. adults have used a dating site/app, including 27% of adults aged 18-24 -- that it's tough to imagine that population being far removed from the general population (6).