I was watching an Australian science program the other day and they had an interesting piece on synaptic connectivity.

Here's the link to the transcript: http://www.abc.net.au/catalyst/stories/s1185573.htm

And here's the bit I want to highlight (emphasis mine)

Narration
If the experiment was done on these girls they'd be divided into three groups.

The first would be shown an instrument but not taught to play - they're the control group.

The second group would be taught simple 5 finger exercises and told to practise them daily.

The third group would be taught the five finger exercises but simply told to imagine practising.

In the original study, after 5 days their brains were scanned to see if there'd been any change.

The control group showed no change in their brain connections.

Baroness Professor Susan Greenfield
However the group that were shown the five finger piano exercises// over five days their brains show a different pattern. The area of the brain that relates to the fingers gets bigger.

Narration
So by practising they could physically change their brain connections, making them bigger and better.

Baroness Professor Susan Greenfield
But more remarkable than that the group that just had to imagine they were doing it also show a similar change in their brain scans.

Narration
So in theory this means we all have the power to improve brain connections just by thinking about it.

My thoughts basically boil down to "yep."

"Why is role playing fun" or "what is it about role playing that's fun" are unanswerably vague questions, right? Only a fool would attempt to offer a single answer that applied to all players or even to a plurality of players.

But if someone put a gun to my head and forced me to suggest a single universal and straightforward answer, I'd say: "The fun is in experiencing successful adaptation to arbitrary* adversity." The adversity can be real ("if I don't come up with a way to win this combat I'll lose my character") or simulated ("if my character doesn't figure out a way to rescue the princess she'll die"). The adaptation can be anything from solving the problem to understanding how to incorporate the consequences of the adversity into one's moral world view. Thus, the fun can be found in different play styles and different Creative Agendas while still coming down to successful adaptation to arbitrary adversity.

And if forced to offer an opinion on why activities that lead to such experiences are fun, I'd venture that it's the same reason sex is fun: because engaging in those activities is beneficial to individual and group survival in a world that deals out arbitrary adversity on a regular basis.

- Walt

*Probably "arbitrary" isn't quite the right word. What I mean is not precisely "unexpected" and not quite "uncontrolled" and not exactly "unavoidable" or "unplanned." I mean adversity that's external, not under one's control, though it could arise from one's own actions. Adversity that cannot be reliably prevented or avoided but can be adapted to, survived, and possibly overcome.

Special note: I don't mean this is THE reason people RP. To be clear, I'm suggesting it's a good, strong attraction for the act of roleplay. One of many.

I recall more studies with a similar result.

Group effects are also possible - if I watch someone trying to learn/practise something, it's been shown that the same learning parts of my brain activate as that person's.

Not so strange that sharing imagination (group role-playing) would cause the same parts of the brain to activate all over the group - but cool anyway. (IMHO)