New Study Links Brain Injuries to "Acquired Sociopathy"
This discovery brings into question how much free will there is in deciding to break the law.
How much of breaking legal or moral laws has to do with free will and how much with circumstances beyond our control has been fodder for philosophical debate for millennia. Mostly, this surrounded socioeconomic and political factors. The introduction of science ushered in whole other aspects.
Those with certain genetic mutations for instance, specifically the gene variant MAOA, are more likely to commit violent acts, research has shown. Others mutations are associated with mental illness, which may also contribute to violent outbursts. Now, the latest research out of Vanderbilt University finds that brain lesions can increase the risk of a person committing a crime. The findings were published in the Proceedings of the National Academy of Sciences (PNAS).
Neuroscientists have debated whether or not there’s a link between brain injuries and violent acts, beginning with the case of Charles Whitman. In 1966 the former marine sniper took a rifle and climbed an observation tower on the campus of the University of Texas, where he shot 11 passersby below dead, until he was subdued by police (he killed 16 that day total, including his wife and mother).
After his death, an autopsy revealed he had a brain tumor—but it’s been much debated whether the tumor contributed to the incident or not. Other serial killers had suffered brain injuries, either from a fall, accident, or physical abuse, including Edmund Kemper, John Wayne Gacy Jr., Jerry Brudos, Gary Heidnik, and Ed Gein. Now, research by Ryan Darby, MD, assistant professor of Neurology at Vanderbilt University Medical Center (VUMC), is reinvigorating the argument.
It shows compelling evidence that lesions in one particular brain network can increase the risk of criminal behavior, what’s technically known as acquired sociopathy. Darby had read about famous cases, including Whitman’s, which inspired the study.
Investigators have long noticed a link between brain injury and criminal behavior. However, how influential brain injuries are to such behavior has been a matter of much debate. Credit: Getty Images.
This is the first brain-mapping study linking lesions to a higher propensity of criminal acts. A lesion is abnormal brain tissue which can occur as a result of trauma, a tumor, or a stroke. What this study found is that lesions occurring not in one specific area of the brain, but in a number of different places, can contribute to the likelihood of the person committing a crime.
Darby and colleagues conducted MRI and CT scans of convicted criminals. These were murderers, rapists, thieves, con artists, and others. The first group consisted of 17 individuals, and linked criminal behavior with brain lesions. But the second, with 23 volunteers, showed lesions in different areas of the brain. Researchers compared these brain scans to enormous neuroimaging datasets of healthy, law-abiding people. They compared each group’s connectomes, or the neural networks connecting brain regions.
Darby and colleagues discovered that although lesions inhabited different brain areas, they resided within the same neural networks in those who took part in criminal activity. Volunteers with a criminal past had lesions in the moral decision-making network, which means an injury here increases the likelihood of criminal behavior.
This network is involved with morality, value-based decision-making, “theory of mind,” and criminality. Theory of mind is being able to understand someone else’s point of view. There was no lacking in the areas where empathy is created however, which is consistent with this Harvard study, which found that psychopaths and sociopaths do have empathy and can feel regret—just a little differently than most people do.
Lesions associated with criminal behavior. These are the lesions from the initial 17 criminal patients, as compared to the brain atlas. Credit: the Proceedings of the National Academy of Sciences.
According to Darby:
We looked at networks involved in morality as well as different psychological processes that researchers have thought might be involved — empathy, cognitive control and other processes that are important for decision making. We saw that it was really morality and value-based decision making — reward and punishment decision making — that the lesions were strongly connected to.
The approach is relatively new and was used in the past to study why patients with certain psychological disorders suffered from delusions or hallucinations. In those studies, neuroscientists hunted down the brain networks the lesions resided in, causing these symptoms. But this is the first time it’s been used to try and understand criminal behavior from a neurological standpoint. Darby and colleagues caution that the fatalists haven’t won the debate on criminality, at least not from this study's results alone.
The researchers attribute only 9% of violence or crime to traumatic brain injury. While 14% is associated with frontal lobe injury. In fact, one 2014 study found that only 20% of the 249 mass murder cases that year could be attributed to a head injury.
There are other factors experts say that influence people to behave in a dangerous or immoral way. Likely, a number of genetic, biological, social, and psychological factors work in concert for such antisocial behavior to occur.
To hear more about the free will vs. destiny debate from a neurological standpoint, click here:
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Whether or not women think beards are sexy has to do with "moral disgust"
- A new study found that women perceive men with facial hair to be more attractive as well as physically and socially dominant.
- Women tend to associate more masculine faces with physical strength, social assertiveness, and formidability.
- Women who display higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, are more likely to prefer hairy faces.
Beards and perceptions of masculinity<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzkxMjM3N30.cH-GqNwP5GVqvstgJWAhBPn1B_lYpVEAI0I7iax7EQw/img.jpg?width=1245&coordinates=0%2C1900%2C0%2C849&height=700" id="caae6" class="rm-shortcode" data-rm-shortcode-id="cb0a355a4e8e1899789bc45f3f7aef56" data-rm-shortcode-name="rebelmouse-image" />
Photo Credit: Wikimedia<p>The study used 919 American (mostly white) women ages 18-70 who rated 30 pictures of men they were shown with various stages of facial hair growth. The photographs depicted men with faces that had been digitally altered to look more feminine or more masculine, with a beard and without a beard. The women rated the men according to perceived attractiveness for long-term and short-term relationships. The study found that the more facial hair the men had, the higher the men were rated on their attractiveness, particularly for their suitability for a long-term relationship.</p><p>Part of this might be attributed to facial masculinity — i.e. protruding brow ridge, wide cheekbones, thick jawline, and deeply set narrow eyes — which conveys information to a woman about a man's underlying health and formidability. Women tend to associate more masculine faces with physical strength and social assertiveness. It can also indicate a man with a superior immune response. The researchers suggested that their findings favoring bearded men could be due to the fact that facial hair enhances the masculine facial features on a man's face, like creating the illusion of a thicker jaw line. This could communicate direct benefits to women like resources and protection that would enhance survival among mothers and their infants. In other words, while a beard doesn't mean superior genetics in and of itself, it might be a primitive, ornamental way of saying, "Hey girl, I'm a testosterone-fueled lean, mean, pathogen fighting machine." <br></p><p>It could also be that a beard becomes its own destiny. The researchers in this study cite prior research that found that by growing a beard, men felt more masculine and had higher levels of serum testosterone, which was linked to a higher level of social dominance. They also tended to subscribe to more old-school beliefs about gender roles in their relationships with women as compared to men with clean-shaven faces.<span></span><br></p>
What does disgust have to do with beard preference?<p>Obviously, not all women dig beards. The researchers were particularly interested in what traits make a women prefer bearded men over clean-shaven faces. They looked into several factors including a woman's disgust levels on various concepts, her desire to become pregnant, and her exposure to facial hair in her personal life. </p><p>According to the study, women who were not into facial hair were turned-off by potential parasites or other critters they imagined could be in the hair or skin. Women ranking high on this "ectoparasite disgust" scale might have viewed beards as a sign of poor grooming habits. However, women who ranked higher in levels of "pathogen" did find the bearded men to be desirable, possibly because they perceived beards as a signal of good health and immune function. An intriguing discovery in the study was links to morality. Women who displayed higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, were more likely to prefer hairy faces. The authors opined that this could reflect a link between beardedness, politically conservative outlooks, and traditional views regarding performances of masculinity in heterosexual relationships.</p>
Additional findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg1My9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTYyNDI1NjUyOX0.P9B8WbmJR0q4nfzYZKbuNSA-2SAigVWJgrQE-_Gxlds/img.gif?width=980" id="49143" class="rm-shortcode" data-rm-shortcode-id="2ed3b1d6f20fc170bf2974646e565e8d" data-rm-shortcode-name="rebelmouse-image" />Giphy<p>The correlations that existed between married and single women's rating on the attractiveness of beards were not particularly clear, although the researchers noted that single and married women who wanted children tended to find beards more attractive than the women who didn't want children. They also found that women with bearded husbands found beards to be more attractive, which might indicate that social exposure to beards influences how desirable they are perceived of as being. Or it could be that men with wives who like beards grow beards.</p><p>It's important to note that culture plays a huge role in how attractive women perceive certain male characteristics as being. This study looked at a small, culturally specific group of American women, so no big, universal claims should be made about masculinity, facial hair, and male desirability to women. However, research like this is important in highlighting how human grooming decisions are driven by much more than fashion trends. Sociobiological, economic, and ecological factors all play a part in the way we choose to present ourselves.</p>
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