Women are four times more likely to give out "passwords" in exchange for chocolate

I'd like to see a more controlled research set myself. Give them a password and such so that they'll think there's a reward, not a particularily big one, if they keep it to themselves for, say, two months, have them log in like once a week or so, to make sure they don't just forget it, then afterwards ask them to make the same trade and see what they get.