Is psychopathy an evolutionary strategy rather than a disorder?

Psychopaths are manipulative, violent, impulsive, and lack empathy — but if psychopathy encourages more frequent reproduction, is it, then, an advantageous strategy?

Is psychopathy an evolutionary strategy rather than a disorder?
Photo credit: Isai Ramos on Unsplash
  • It's tempting to think of psychopathy as a kind of aberrant mental condition, but several studies suggest that it may be an evolutionary strategy.
  • A study compared the genetic profiles of psychopaths with individuals who were more likely to have children younger and more frequently and found significant overlap.
  • This suggests that the qualities that bring about psychopathy are also qualities that encourage more frequent reproduction, making psychopathy an advantageous strategy.

From an evolutionary perspective, it seems odd that we would have psychopaths among our numbers at all. A great deal of what's made humanity a successful species is our social cohesiveness, our empathy toward one another, and our understanding of right and wrong. What benefit could there be for individuals to simply lack these socially binding qualities and to feel a tendency toward violence to boot? The evolutionary role of psychopaths becomes even stranger when you consider the fact that psychopaths are at higher risk for becoming disabled or dying early owing to their impulsivity and reckless behavior.

It's tempting to say that psychopathy is simply the result of a short circuit in the complicated wiring that makes up our brains. However, it may be the case that psychopaths are simply employing a different reproductive strategy than the rest of us. At least, that's what Jorim Tielbeek and colleagues argue.

Looking at the genome

While psychopathy is believed to have some environmental causes, much of what brings it about is genetic. We know that there are certain mutations that encourage psychopathic personalities. Tielbeek and colleagues were curious as to whether these mutations also conferred some other kind of benefit. So, they looked at two large databases containing genotypic data on over 31,000 individuals. A prior study had also uncovered the genetic profiles of individuals who were more likely to have children younger and to have more children overall. By looking at the overlap of these two genetic profiles, the research team was able to see whether there was any correlation between the two sets.

They found that there was, indeed, a fairly significant overlap. The genes associated with having children earlier and more often are also associated with the genes that give psychopaths the characteristics that make them psychopathic, like a lack of empathy.

Why psychopathy exists

Photo by Jesús Rocha on Unsplash

It seems counterintuitive, but this finding fits well with what we understand about psychopaths. Previous research has found that psychopaths are often superficially charming, which enables them to attract others in the short term. In the long term, though, this façade crumbles over time. Psychopaths are also prone to greater disinhibition than others, meaning they have problems with impulse control and tend to seek immediate gratification. Combined, these traits would make psychopaths sexually promiscuous, and their disregard for social norms makes them more prone to poaching others' mates or sexual assault, a theory that has been supported by a number of other studies.

But if psychopathy can be a way to have more offspring, why aren't there more psychopaths? After all, Tielbeek and his colleagues' study showed that psychopaths are more likely to have more children, and we know that there is a significant genetic component in psychopathy. Wouldn't the psychopathic gene out-reproduce the non-psychopathic gene?

Why we aren't all psychopaths

One theory is that there's a kind of balancing act going on in the human genome. Highly psychopathic individuals make up about 1 percent of the human population. According to this theory, this number is so low because psychopaths are a kind of social parasite that can only thrive in groups predominantly made up of people who can be taken advantage of; that is, environments made up of moral, empathetic, socially-minded individuals. In groups like these, its easier to take advantage of others' trust to gain resources, like access to sexual partners. If there were too many psychopaths, then this system wouldn't work, and a given social group might become stricter about enforcing group norms. It should be noted that this a difficult theory to test directly.

There's also the idea that the "fast" lifestyles of psychopathic individuals may encourage them to reproduce more frequently, but it doesn't encourage them to invest any of themselves in their offspring's success. Individuals with "slow" lifestyles have fewer children but tend to stick around to make sure their children develop into healthy, competent, and successful adults. The psychopath wouldn't care about that — they demand instant gratification and aren't particularly attracted to the promise of future rewards. In this way, fewer offspring with the psychopathic genome would go on to be in a position to reproduce.

Evolution doesn't have a perspective or an opinion on things. It's a neutral process that selects what works. What these studies show is that, at least when it comes to human evolution, psychopathy is more of a feature than a bug.

A landslide is imminent and so is its tsunami

An open letter predicts that a massive wall of rock is about to plunge into Barry Arm Fjord in Alaska.

Image source: Christian Zimmerman/USGS/Big Think
Surprising Science
  • A remote area visited by tourists and cruises, and home to fishing villages, is about to be visited by a devastating tsunami.
  • A wall of rock exposed by a receding glacier is about crash into the waters below.
  • Glaciers hold such areas together — and when they're gone, bad stuff can be left behind.

The Barry Glacier gives its name to Alaska's Barry Arm Fjord, and a new open letter forecasts trouble ahead.

Thanks to global warming, the glacier has been retreating, so far removing two-thirds of its support for a steep mile-long slope, or scarp, containing perhaps 500 million cubic meters of material. (Think the Hoover Dam times several hundred.) The slope has been moving slowly since 1957, but scientists say it's become an avalanche waiting to happen, maybe within the next year, and likely within 20. When it does come crashing down into the fjord, it could set in motion a frightening tsunami overwhelming the fjord's normally peaceful waters .

"It could happen anytime, but the risk just goes way up as this glacier recedes," says hydrologist Anna Liljedahl of Woods Hole, one of the signatories to the letter.

The Barry Arm Fjord

Camping on the fjord's Black Sand Beach

Image source: Matt Zimmerman

The Barry Arm Fjord is a stretch of water between the Harriman Fjord and the Port Wills Fjord, located at the northwest corner of the well-known Prince William Sound. It's a beautiful area, home to a few hundred people supporting the local fishing industry, and it's also a popular destination for tourists — its Black Sand Beach is one of Alaska's most scenic — and cruise ships.

Not Alaska’s first watery rodeo, but likely the biggest

Image source: whrc.org

There have been at least two similar events in the state's recent history, though not on such a massive scale. On July 9, 1958, an earthquake nearby caused 40 million cubic yards of rock to suddenly slide 2,000 feet down into Lituya Bay, producing a tsunami whose peak waves reportedly reached 1,720 feet in height. By the time the wall of water reached the mouth of the bay, it was still 75 feet high. At Taan Fjord in 2015, a landslide caused a tsunami that crested at 600 feet. Both of these events thankfully occurred in sparsely populated areas, so few fatalities occurred.

The Barry Arm event will be larger than either of these by far.

"This is an enormous slope — the mass that could fail weighs over a billion tonnes," said geologist Dave Petley, speaking to Earther. "The internal structure of that rock mass, which will determine whether it collapses, is very complex. At the moment we don't know enough about it to be able to forecast its future behavior."

Outside of Alaska, on the west coast of Greenland, a landslide-produced tsunami towered 300 feet high, obliterating a fishing village in its path.

What the letter predicts for Barry Arm Fjord

Moving slowly at first...

Image source: whrc.org

"The effects would be especially severe near where the landslide enters the water at the head of Barry Arm. Additionally, areas of shallow water, or low-lying land near the shore, would be in danger even further from the source. A minor failure may not produce significant impacts beyond the inner parts of the fiord, while a complete failure could be destructive throughout Barry Arm, Harriman Fiord, and parts of Port Wells. Our initial results show complex impacts further from the landslide than Barry Arm, with over 30 foot waves in some distant bays, including Whittier."

The discovery of the impeding landslide began with an observation by the sister of geologist Hig Higman of Ground Truth, an organization in Seldovia, Alaska. Artist Valisa Higman was vacationing in the area and sent her brother some photos of worrying fractures she noticed in the slope, taken while she was on a boat cruising the fjord.

Higman confirmed his sister's hunch via available satellite imagery and, digging deeper, found that between 2009 and 2015 the slope had moved 600 feet downhill, leaving a prominent scar.

Ohio State's Chunli Dai unearthed a connection between the movement and the receding of the Barry Glacier. Comparison of the Barry Arm slope with other similar areas, combined with computer modeling of the possible resulting tsunamis, led to the publication of the group's letter.

While the full group of signatories from 14 organizations and institutions has only been working on the situation for a month, the implications were immediately clear. The signers include experts from Ohio State University, the University of Southern California, and the Anchorage and Fairbanks campuses of the University of Alaska.

Once informed of the open letter's contents, the Alaska's Department of Natural Resources immediately released a warning that "an increasingly likely landslide could generate a wave with devastating effects on fishermen and recreationalists."

How do you prepare for something like this?

Image source: whrc.org

The obvious question is what can be done to prepare for the landslide and tsunami? For one thing, there's more to understand about the upcoming event, and the researchers lay out their plan in the letter:

"To inform and refine hazard mitigation efforts, we would like to pursue several lines of investigation: Detect changes in the slope that might forewarn of a landslide, better understand what could trigger a landslide, and refine tsunami model projections. By mapping the landslide and nearby terrain, both above and below sea level, we can more accurately determine the basic physical dimensions of the landslide. This can be paired with GPS and seismic measurements made over time to see how the slope responds to changes in the glacier and to events like rainstorms and earthquakes. Field and satellite data can support near-real time hazard monitoring, while computer models of landslide and tsunami scenarios can help identify specific places that are most at risk."

In the letter, the authors reached out to those living in and visiting the area, asking, "What specific questions are most important to you?" and "What could be done to reduce the danger to people who want to visit or work in Barry Arm?" They also invited locals to let them know about any changes, including even small rock-falls and landslides.

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