Why are social mixed-choirs dominated by women? Why are social mixed-jams dominated by men?

Possibilities?:
don't men's voices change more radically when they hit puberty? -- wouldn't this cause more of them to temporarily/permanently lose interest in singing.
it's harder to harmonize when your voice is the lowest in the lot -- this can make it harder to even understand/appreciate harmony.
men are more often drawn to situations where they can show off -- difficult in a choir, and hey, children! can sing in choirs, but they generally can't play instruments very well.
jams are often competitive
jams are often exploratory in nature, with nobody really knowing where they're going; choirs aren't
most jams are unamplified and men, who often can sing louder than women, sometimes possess the only voices easily heard over the instruments
men take more pride in owning tools more than women
men take more pride in mastering tools more than women
men are more upset by percieved impotence in any task

Note that none of these suggestions has much to do with musical talent.

Other points: Math and music? I think the experiments were done with easy high school math and *appreciating* Mozart-ish music. It's interesting, but doesn't prove anything about higher math and the talent to *make* music.

If you want to study the "best" people in music -- fine. That's only raises the question of whether the most talented people always develop their talents.