Why do men commit violent interpersonal crimes?

In every single human society without an exception, men commit an overwhelming majority of all crimes and acts of violence. Why is this? Why are men so much more criminal and violent than women?

There are many cultural universals -- features of human society that are shared by all known cultures. Donald E. Brown provided the original list of “human universals” (and wrote a whole book about them, aptly titled Human Universals) in 1991, and Steven Pinker updated the list in 2002 in his book The Blank Slate. There are probably so many cultural universals (contrary to what Franz Boas and cultural determinists think) because human culture is a manifestation of human nature at the level of society, and human nature is universal to all humans. This is why all human cultures are more or less the same, and there are so many cultural universals. And among the many cultural universals is the fact that men in every society are so much more criminal and violent than women.

As I explain in a previous post, humans throughout their evolutionary history were effectively polygynous, and many married men had multiple wives. In a polygynous society, some males monopolize reproductive access to all females while other males are left out; in such a society, some males do not get to reproduce at all, while almost all females do. In other words, there is a vast sex difference in fitness variance; the difference between “winners” and “losers” in the reproductive game is much greater among men than among women. This large sex difference in fitness variance makes males highly competitive in their effort not to be left out of the reproductive game altogether. This competition among men leads to a high level of violence (murder, assault, and battery) among them. The large number of homicides between men (compared to the number of homicides between women, or between the sexes) is a direct consequence of this male competition for mates.

In their comprehensive study of homicides, the leading evolutionary psychologists Martin Daly and Margo Wilson note that most homicides between men originate from what is known as “trivial altercations.” A typical homicide in real life is not one depicted in an episode of Columbo: premeditated, well planned, and nearly perfectly executed by a meticulous and intelligent murderer. Instead, it begins as a fight about trivial matters of honor, status, and reputation between men (such as when one man insults another or makes moves on another’s girlfriend). Fights escalate because neither is willing to back down, until they become violent and one of the men ends up dead. Because women prefer to mate with men of high status and good reputation, a man’s status and reputation directly correlates with his reproductive success; the higher the status and the better the reputation of the man, the more reproductively successful he is. Men are therefore highly motivated (albeit unconsciously) to protect their honor, and often go to extreme lengths to do so. Daly and Wilson thus explain homicides between men in terms of their (largely unconscious) desire to protect their status and reputation in their attempt to gain reproductive access to women.

Rape may appear to be an exception to this reasoning because, unlike murders and assaults, the victims of rape are usually women, and there is therefore no male competition for status and reputation. However, the same psychological mechanism that compels men to gain reproductive access to women by competing with each other can also motivate men to commit rape. Predatory rapists are overwhelmingly men of lower class and status, who have very dim prospects of gaining legitimate reproductive access to women. While it is not a manifestation of male intrasexual competition and violence, rape may be motivated by men’s psychological mechanisms that urge them to gain reproductive access to women illegitimately when they do not have the legitimate means to do so.

Incidentally, this is why the death penalty may not deter murder. The logic of the death penalty assumes that most murders are premeditated. A potential murderer carefully and rationally weighs the costs and benefits of the act, and decides not to murder if the costs outweigh the benefits. This might describe a fictional murderer on Columbo, but not real-life murderers, who do not stop to think before escalating their trivial altercations into fatal fights.

The logic of the death penalty also assumes that execution is the worst fate possible. From an evolutionary psychological perspective, there is something worse than death, and it is the total reproductive failure that awaits any man who does not compete for mates in a polygynous society. If they compete and fight with other men, they may die, by being either killed by the other man or executed by the state. If they don’t compete, however, they will definitely die, reproductively, by leaving no copies of their genes. So they might as well compete even at the risk of death; the alternative is much worse.

In my next post, I will explain how we can extend this logic to explain why men commit property crimes.