Psychology may help explain why male and female serial killers differ

Sex differences in serial murder.


A recent study has found that male serial killers and female serial killers choose their victims and commit crimes in different ways. Male serial killers choose their victims who are stranger to them whereas female target people around them who they may already know, often for financial gain.

According to scientists, this difference is due to thousands of years of psychological evolution. As humans lived as hunter-gatherers for about 95 percent of history, these ancient roles could help explain these differences.

Marissa Harrison, associate professor of psychology at Penn State Harrisburg, said, “If a murder has been committed without a known suspect, you can sometimes use details of the crime to form a profile of what the perpetrator might look like. So if you know that men are more likely to commit a crime in a certain way and women are more likely to do it another, hopefully, it can help investigators go down the correct path.”

“While there is considerable public interest in serial killers, there has been little research on these crimes, possibly because serial killers are relatively rare. But while working on a previous study, we noticed a difference between male and female serial-killing patterns that she was interested in exploring.”

“Historically, men hunted animals as prey and women gathered nearby resources, like grains and plants, for food. As an evolutionary psychologist, I wondered if something left over from these old roles could be affecting how male and female serial killers choose their victims.”

For the study, scientists gathered the data using mass media method. They browsed through reputable, reliable news sources like the Associated Press, Reuters, TV networks, and national and local newspapers for data about serial murders. Moreover, they used data on 55 female and 55 male serial killers from the United States.

Examining the data, scientists found that male serial killers were almost six times as likely to kill a stranger, while female serial killers were nearly twice as likely to kill a person they already knew. 65.4 percent of male serial killers stalked their victims, compared to 3.6 percent of female serial killers.

As scientists used media sources for the study, they also found that serial killers were nicknamed according to the nature of crime by the media. For example, Women were more likely to be given nicknames that denote their gender — like ‘Jolly Jane’ or ‘Tiger Woman’. While men were more likely to be given nicknames that suggest the brutality of their crimes, like the Kansas City Slasher.

“Evolution doesn’t mean you’re predetermined to do certain things or act a certain way. It means that it may be possible to make predictions about behavior based on our evolutionary past. In this case, I do believe that these behaviors are reminiscent of sex-specific behaviors or assignments in the ancestral environment. And perhaps we can understand this better through an evolutionary lens.”

The study is published in the journal Evolutionary Behavioral Sciences.


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