You know what? I notice a lot of lower level people in the actuary field that do not think they fit the stereortype of an actuary. While they may not fit the "backroom actuary" mold, most of the time they are still huge boring, nerds at heart.
Going out to cheesy bars and getting trashed for the sake of getting trashed does not make you cool. I'd lump these "extroverted actuaries" you speak of in the same boat as scenesters and hipsters. That is to say, they're all (typically) douchebags--a bunch of posers.
I've seen it time and time again. When push comes to shove, their true nature shines through. If coming close to a bar room brawl, they will back down in a heartbeat. When a group of hotties are in the room, they stay put contemplating on what could've been (and it really could not have been since most male actuarial types are ugly or effeminate). The females are even worse: "Look at me. I have tits!!!" ... Yeah, you have tits, but you're still ugly and boring.
Please, nerds, stop frontin'