From “Scientific Success: What’s Love Got to Do With It?” via gnxp.com:
Several years ago, Satoshi Kanazawa, then a psychologist at the University of Canterbury in Christchurch, New Zealand, analyzed a biographical database of 280 great scientists–mathematicians, physicists, chemists, and biologists. When he calculated the age of each scientist at the peak of his career–the sample was predominantly male–Kanazawa noted an interesting trend. After a crest during the third decade of life, scientific productivity–as evidenced by major discoveries and publications–fell off dramatically with age. When he looked at the marital history of the sample, he found that the decline in productivity was less severe among men who had never been married. As a group, unmarried scientists continued to achieve well into their late 50s, and their rates of decline were slower.
“The productivity of male scientists tends to drop right after marriage,” says Kanazawa in an e-mail interview from his current office at the London School of Economics and Political Science in the United Kingdom. “Scientists tend to ‘desist’ from scientific research upon marriage, just like criminals desist from crime upon marriage.”
Kanazawa’s perhaps controversial perspective is that of an evolutionary psychologist. “Men conduct scientific research (or do anything else) in order to attract women and get married (albeit unconsciously),” he says. “What’s the point of doing science (or anything else) if one is already married? Marriage (or, more accurately reproductive success, which men can usually attain only through marriage) is the goal; science or anything else men do is but a means. From my perspective, scientists are no different than anybody else; evolutionary psychology applies to all humans equally,” he adds.