Re: More perspectives...
When I was back in college, I was talking to a Jewish friend about how it seemed like so many great scientists and thinkers seemed to be Jewish. His theory was that for many generations throughout history (prior to the Lutheran reforms, I would guess), the brightest and most promising children were encouraged to join the clergy, which was considered a prestigious calling then. While Christians went into the priesthood, and weeded themselves out of the gene pool, Jewish kids became rabbis, and were encouraged to have LOTS of kids. Natural selection for brains, in his opinion.
Seemed like an interesting theory to me at the time.