I must be the last person in the world to come across Jonathan Rauch's hilarious article on "Caring for Your Introvert," from an issue of The Atlantic some six years ago. Introversion, of course, is nothing new: Carl Jung coined the term as part of his now-largely-obsolete theory of "psychic energy", but the term continues in broad circulation due, I imagine, to the popularity of the rather silly Myers-Briggs personality test. The Atlantic article, however, seems to have struck a nerve: many readers, including yours truly, were stunned at how closely Rauch captured their own experience. It all makes sense now! There's a reason why I leave social events feeling as though my brains have been sucked through my ears with a straw!
The world of performing musicians, it seems to me, is one where the dice are stacked in favour of introverts. Think of it: weeks of meticulous practice; hours spent travelling from one city to another, then the ephemeral performance itself. All solitary activities. After the concert, you make brief conversation with audience members before beating a hasty retreat; there's always another performance on the horizon, and so it's right back on the road and off to the next thing. Ironic as it may seem, public performance is tailor-made for people who are uncomfortable in large groups: the only social interaction required is in a highly prescribed form, and is over in an hour or so.
(This obviously applies mostly to solo performers, but it can be true of chamber musicians as well. The sort of social interaction required in chamber groups is extremely focused and businesslike, entirely unlike the rambling small talk that annoys introverts. Large ensemble performance, of course, can be a different bag entirely; many people join choirs or orchestras specifically for the social dynamic. Ironically, again it's the most public figure in the ensemble - the conductor - who often tends towards introversion. Some of the best conductors I've known are almost certainly introverts, their larger-than-life persona in rehearsal as much a performance as any of their motions the podium.)
I think this odd coincidence probably says something about our profession, but I have no clue what it might be.