Why Do Less Intelligent People Commit Some Crimes But Not Others?

If less intelligent individuals are more likely to commit crimes, why are they less likely to use illegal substances?

In an earlier post, I explain why criminals in general are less intelligent than noncriminals. Then, in my last post, I explain why less intelligent individuals are less likely to consume psychoactive drugs, such as marijuana, cocaine, and heroin. The consumption of such psychoactive drugs is illegal in both the United Kingdom and the United States; in other words, it is a crime to use such substances. So why aren’t less intelligent individuals more likely to commit the crime of drug use? Is there a contradiction in these two observations?

As I explain in my earlier post, less intelligent individuals are more likely to commit crimes for two reasons. First, behavior that counts as criminal in a civilized society today – such as murder, rape, assault, robbery, and theft – were probably routine means of intrasexual mate competition, resource acquisition, and mating in the ancestral environment. Our ancestors probably engaged in such behavior routinely; it is evolutionarily familiar. Second, many of the institutions and technology that detect and punish criminal behavior today – CCTV cameras, the police, the courts, and the prisons – are evolutionarily novel. Since less intelligent individuals are more likely to lack the ability to comprehend and deal with evolutionarily novel entities and situations of all kinds, they are more likely to resort to evolutionarily familiar means of intrasexual mate competition, resource acquisition, and mating instead of evolutionarily novel means, and less likely to be deterred by the evolutionarily novel means of social control.

In other words, less intelligent individuals are more likely to engage in crime, not because it is criminal per se, but because most of it is evolutionarily familiar. Less intelligent individuals are less likely to engage in behavior that is evolutionarily novel, whether it is defined by the civilized society as criminal or not.

This is why less intelligent individuals are less likely to consume evolutionarily novel substances of psychoactive drugs, even though it is criminal. Less intelligent individuals are probably less likely to engage in other evolutionarily novel criminal behavior, such as check forgery, insider trading, and embezzlement, even apart from the fact that more intelligent individuals are probably more likely to have the opportunity to commit such crimes. (That is true of insider trading and embezzlement, but not check forgery.)

The twin facts that 1) the less intelligent individuals are simultaneously less likely to consume the legal substance of alcohol and the illegal substances of marijuana, cocaine, and heroin, and that 2) they are more likely to commit the crime of murder, rape, and theft but not the crime of drug consumption, together seem to suggest that what matters is not legality but evolutionary novelty. Less intelligent individuals are more likely to commit crimes, but only if they are evolutionarily familiar.