Do these people who say they wouldn't join Mensa because the people aren't smart enough, not join any groups of people less smart than Mensans? No hiking club or soccer team?
If you enjoy what they do, then go for it. I don't know what they do.
Key difference: if you're joining Mensa, you're doing it for the smart people. (Well, that and the signalling, but I think we've established now that the signalling is unlikely to be useful in this case. Or perhaps in any other.)
I would usually avoid going to a restaurant if the food weren't distinctly better than I could make. That wouldn't stop me visiting a friend for dinner just because s/he doesn't cook much better than I do.
It's not a typical OB/LW subject, but Robin correctly pointed out that most rationalists are outside OB/LW, and so I'm asking about one of the organizations that might hold many of them.
A couple of weeks ago I took a supervised IQ test by Mensa due to curiosity and for some CV padding (cheap signaling is a perfectly rational thing to do). Now I got a letter back from them that I'm in top whatever %, and they'd like me to join. I wasn't really planning joining Mensa, or anything else, so I'm wondering - does any of fellow rationalists have any experience with them? Is it worth bothering?
As a bonus here's a quick description of their supervised IQ testing process:
They compute percentile based on both tests separately, and higher of two counts as the result. So you can has 0 points on one (if at all possible), and respectively 148 / 132 on the other, and you're in (2 stddev above mean, or top 2%). The tests obviously check knowledge of obscure English words and meanings and ability to deal with pressure in addition to intelligence as such. Well, I guess no test is perfect.
So Mensa - good or bad?