There is a massive, albeit subtle to those of us not really paying attention, grab being made by the field of sociology right now. The social science is making a move to wrestle control of the study of murder from its soft science sister field of psychology. I find this intensely interesting. For the last X decades, since psychology has been around really, the field has had complete and unadulterated domain over the crime of murder. When Jack the Ripper was running around Whitechapel, the cops rounded up everyone who even seemed crazy and sent them off to asylums. The tacit implication was that anyone who butchered women must be insane. That concept hasn’t faded much in the last 120 years. You murder someone, you’re crazy — especially in the case of stranger murders like serial killing, which lack a clear motive.

Psychology has spent much time and effort attempting to explain what goes on in the brain of an individual that leads him or her (mostly him) to murder someone he doesn’t know. Was it the dreaded combination of an overbearing mother and absent father who ultimately abandon the child? Is it some series of synapses that form during childhood evisceration of frogs or chipmunks? Is it the result of abuse? A lack of breastfeeding?

“What?! What is it?!” ask psychologists as they stroke their beards and cluck their tongues. Sociology, I found, is tired of waiting around for an answer.

What they’ve come up with, points out Kevin Haggerty — a University of Alberta sociologist I came across during research for a Discovery News article I wrote, who first revealed sociology’s master plan to take murder from psychology — is that serial murderers have personality disorders. “Of course they have personality disorders,” he told me.

I expected Haggerty, who wrote a paper on how modern society has shaped serial murderers’ behavior, to be a bit timid when talking about the role of psychology in examining murder. I expected him to simper about how sociology could maybe, possibly, you know, help psychology explain serial killers, a little bit at least, if psychology would let them, of course. That was not the case. Haggerty feels that psychology has utterly failed in its mission to explain serial murder specifically.

Okay, maybe so. I hadn’t thought of it before, but psychology really doesn’t have a pat answer that uniformly explains serial killers. But sociology certainly can’t explain it any better, I imagined. How can sociology, which is so terribly closely linked to eye-bleedingly boring undertakings like censuses, explain what goes on in the brain of a person who takes another person’s life for no reason? By taking the brain pretty much out of the equation. Haggerty explained it to me like this when I wrote him and asked for further explanation:

If society didn’t shape or foster murder, then murder rates would be pretty much uniform across time and space. That is not the case, however, which suggests that society and its structure (or lack of structure at different points in time) do play a role in fostering murder. So things like an absence of informal protection like family, a permissive attitude of violence toward women, television, societal breakdown “(there is a famous line of thought in sociology which talks about a general breakdown of social norms in times of mass social disruption which effectively ‘frees up’ people to be more deviant, or even more prone to kill),” Haggerty says — all of these things can lead to the murder of one person by another.

There is research that backs up the sociological view of murder. One study of the United States found that regions that maintain a culture of violence — high domestic abuse rates, assaults and, interestingly with states that have the death penalty — have higher rates of serial murder. But there’s one prickly question that sociology has to tackle: why one guy in a town murders while another guy who has a similar life experience doesn’t.  It’s here where sociology and psychology might come together. “It is in considering this relationship between how social factors impinge on specific individual where we can indeed have a fruitful dialogue between the social sciences and the ‘psy’ sciences,” Haggerty said.

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More on HowStuffWorks.com:
How Serial Killers Work
How Jack the Ripper Worked
How the Census Works