If I were younger and looking for a job in sociology, maybe I would have done some of that formal research instead of posting half-assed speculation on news.yc. :)
It isn't exactly as mechanical_fish says, but it's along the same lines, and critically, it tries to explain why scientific contributions fade dramatically after marriage.
Another interesting article, while doesn't count as research, likely because there isn't much of a sample size, and probably wouldn't be one anymore, is the Richard Hamming talk pg posted here: http://www.paulgraham.com/hamming.html
After these inputs, a valid hypothesis is "monotony kills creativity." There are studies that show this idea is generally correct; if you ask, the ones I would cite to support this hypothesis would be ones about education, where stimulating environments correlate to achievement. Research in this area should be easy to find.
