>why would someone who knows they are a weak swimmer, try to go through BUD/S?
My answer? Because they're boys.
There was a really interesting study done recently, mostly to assess competetiveness, but it shows other stuff. Essentially, people were given a short test (add 5 number in your head) and then rewarded.
In test number one, the participant was paid 50 cents for every correct answer. Men and women performed equally.
In test number two, there was competition between 2 people and you got $2 for being the first done, or $0 for being the 2nd. Men and women performed equally. They were assessed afterward and knew how well they did compared to everyone else.
In test number three, you had the option of doing the test for 50 cents an answer, or compteting for $2/$0. Most of the women, even the ones who were very good in competition, chose the piecemeal reward despite knowing the results of their competition. Most of the men, even the ones who lost their shirts in competition, chose the competetive payout. A small number of women competed but a vast majority took the safe payment. The vast majority of men took the competition independent of ability.
At any rate, *my* conclusion to this is that most guys don't seem to process the concept of "can't do that" whereas this sense is overdeveloped in most women. I'm pretty sure I printed out that study in full as I thought it was fascinating and made me feel better about risk aversion tendencies. But this tendency to have completely out of whack assessments of your ability w.r.t. the task at hand seems to go both ways. Men overestimate ability, women underestimate ability. And I'm pretty sure the test takers were college students, so that would account for tendencies of 20 year old males to think they could swim when they can't.
-Erika