Why Psychopathic Personality Traits Never Fully Disappear

Scientists explore how selfish and marginally psychopathic personality traits perpetuate in a society.

By Mark Travers, Ph.D. | March 17, 2022

A new evolutionary psychology study published in the academic journal PLOS ONE explores the conditions under which selfish, risk-seeking, and other potentially problematic personality traits can exist in a society and even provide a benefit to groups and communities as a whole.

"Selfish and risk-seeking attitudes are widely observed in our everyday encounters," says author Martina Testori from the University of Southampton. "While evolutionary theories usually favor an individualistic point of view — that is, the strongest survives while the weaker perishes — we were interested in a more collective point of view. We wanted to know whether selfish and risk-seeking traits can be beneficial not only to the individual but also to the community."

To test this idea, the researchers created an agent-based model — a computer game of sorts — to simulate the actions and interactions of two personality types existing together in a simplified society: selfish risk-seekers and generous risk-averse. In the simulation, the personality types chose strategies to harvest resources from their environment. Some strategies were riskier than others. The risky strategies were favored by the selfish risk-seeker personality type. The personality types also decided whether they would share resources with the rest of their community, with sharing preferred by the generous risk-averse type.

The simulated society was able to account for a variety of other factors such as environmental conditions, mortality rates, and the reproduction and mutation of personality types over time. This allowed the researchers to understand the behaviors and emerging properties of the group, with the goal of assessing changes in the composition of personality types in the group as a whole.

They found that, in certain cases, selfish risk-seekers would outperform generous risk-averse personality types. This tended to occur under conditions where group survival was not easy but moderately challenged (e.g., under conditions of greater environmental risk).

"This supports the theory that selfish and risk-seeking traits combined are not dysfunctional but rather can be evolutionarily advantageous," say the authors.

The benefit for societies as a whole is not as clear, but the authors point out that when generous personality types are unconditionally cooperative, communities with a greater percentage of selfish risk-seekers grow to a larger size — suggesting some advantage to the society overall. Under special circumstances, selfish risk-seekers can even comprise a majority of the population (without leading to its collapse).

The authors use this as a means to explain the existence of dark personality traits, such as psychopathy, callousness, and Machiavellianism.

"Our results point towards an evolutionarily adaptive role of selfishness and risk-seeking behaviors, while also marginally supporting the adaptive theory that psychopathic traits may not be a dysfunction but rather an adaptive consequence of human evolution," says Testori.

When asked whether selfish risk-seeking is inherently 'better' than generous risk-aversion, Testori explains that it is difficult to establish which of the two combinations of traits is inherently better and that several exogenous factors might play a role in establishing which behavior is better in which condition.

In the future, the authors would like to uncouple the personality traits of selfishness and risk-seeking to allow for more complex personality combinations to emerge in their simulated society.

"By modeling each behavioral component separately, it might be possible to observe whether it is the combination of selfish and risk-seeking behaviors that is evolutionarily adaptive or whether the evolution is driven by the dynamics of individual traits," says Testori.

A full interview with Martina Testori discussing her research on societal cooperation can be found here: Are there advantages to being a selfish and risk-seeking person?