[amirmc]

While it might be interesting to do a comparison of extreme sports and entrepreneurship, I don't think we could draw any meaningful conclusions (neither one depends on the other).

You might find the following article interesting, published in Nature in 2008. The researchers compare entrepreneurs with managers (controlling for age etc). It doesn't really make the same distinction I did in my previous comment (re risk tolerant vs seeking) but it's relevant nonetheless. The paper is: Lawrence et al The Innovative Brain (http://dx.doi.org/10.1038/456168a) and slightly off-topic comment Hermann Hauser (http://dx.doi.org/10.1038/456700c)

...this risk-taking performance in the entrepreneurs was accompanied by elevated scores on personality impulsiveness measures and superior cognitive-flexibility performance. We conclude that entrepreneurs and managers do equally well when asked to perform cold decision-making tasks, but differences emerge in the context of risky or emotional decisions.

I'd argue that there weren't so much risk-seeking but the willingness to place bigger bets would indicate risk-tolerance (that's my interpretation, anyway)

If you don't have access to the journal, I've dumped them both in the following pdf. It'll be there for at least the next week but no guarantees beyond that (if you're reading this and it's gone, email me for a copy) http://dl.dropbox.com/u/486678/InnovativeBrain.pdf

Aside: So sorry to see notify go. I'd probably never have seen this comment if I hadn't got an email about it.