“For nearly a quarter of a century, criminologists have known about the “age-crime curve.” In every society at all historical times, the tendency to commit crimes and other risk-taking behavior rapidly increases in early adolescence, peaks in late adolescence and early adulthood, rapidly decreases throughout the 20s and 30s, and levels off in middle age.

This curve is not limited to crime. The same age profile characterizes every quantifiable human behavior that is public (i.e., perceived by many potential mates) and costly (i.e., not affordable by all sexual competitors). The relationship between age and productivity among male jazz musicians, male painters, male writers, and male scientists—which might be called the “age-genius curve”—is essentially the same as the age-crime curve. Their productivity—the expressions of their genius—quickly peaks in early adulthood, and then equally quickly declines throughout adulthood. The age-genius curve among their female counterparts is much less pronounced; it does not peak or vary as much as a function of age.

Paul McCartney has not written a hit song in years, and now spends much of his time painting. Bill Gates is now a respectable businessman and philanthropist, and is no longer a computer whiz kid. J.D. Salinger now lives as a total recluse and has not published anything in more than three decades. Orson Welles was a mere 26 when he wrote, produced, directed, and starred in Citizen Kane.

A single theory can explain the productivity of both creative geniuses and criminals over the life course: Both crime and genius are expressions of young men’s competitive desires, whose ultimate function in the ancestral environment would have been to increase reproductive success.

In the physical competition for mates, those who are competitive may act violently toward their male rivals. Men who are less inclined toward crime and violence may express their competitiveness through their creative activities.

The cost of competition, however, rises dramatically when a man has children, when his energies and resources are put to better use protecting and investing in them. The birth of the first child usually occurs several years after puberty because men need some time to accumulate sufficient resources and attain sufficient status to attract their first mate. There is therefore a gap of several years between the rapid rise in the benefits of competition and similarly rapid rise in its costs. Productivity rapidly declines in late adulthood as the costs of competition rise and cancel its benefits.

These calculations have been performed by natural and sexual selection, so to speak, which then equips male brains with a psychological mechanism to incline them to be increasingly competitive immediately after puberty and make them less competitive right after the birth of their first child. Men simply do not feel like acting violently, stealing, or conducting additional scientific experiments, or they just want to settle down after the birth of their child but they do not know exactly why.”