What happens when lonely men, embittered by a sense of failure in the sexual marketplace, find each other and form communities on the internet? The result can be deadly.

new paper by Harvard psychology postdoc Miriam Lindner explores the rise of male “incels,” short for involuntary celibates, and their susceptibility to extremist ideologies and behaviors. Linder argues that despite a string of mass shootings and violent attacks by men espousing incel ideologies in recent years there has been a relative lack of research into the drivers behind the phenomenon.

Lindner uses an evolutionary psychology framework to understand the behavior of these men amid the accelerating social and economic shifts in gender roles and the ways the internet makes possible an “ecology where incel beliefs can thrive and make violence attractive.”

Essentially, Lindner finds these behaviors are rooted in those that proved to be most evolutionarily advantageous and so more likely to be passed along to a next generation. Our ancestors have, according to scholars, passed down a set of inherited tendencies involving male aggression and female selectivity of mates.

“An evolved male psychology makes them, on average, more likely to respond negatively to sexual aggression, and is inclined to coerce women, sexually,” Lindner said. “If we assume that that male psychology exists, we can see how the environment can amplify or dampen that.”

She went on to explain that while men might desire greater control over the selection process, the balance of power has shifted even more decidedly in favor of women. Female empowerment and medical advances (especially birth control), along with greater economic independence, means modern women have greater freedom to choose whom they want on their own terms, or even not at all.

“Women, now that we are in a position where we don’t need to rely on a man to be financially stable, we have that freedom to express more the types of attributes that we are looking for in a long-term partner,” Lindner said.

In fact, a significant percentage of women are choosing to be celibate or single. Lindner cites research by Anna Brown at the Pew Research Center, which found that, “Sixty-one percent of single men were looking for a relationship or dates, but only 38 percent of women reported doing so.”

All of these factors, paired with online dating — an environment that amplifies users’ perceptions of being desirable — have contributed to the rise of violent male ideologies.

“We’re seeing that on dating apps, a lot of cues are being amplified,” she said. “And so you can go onto the internet and what you will see is that women will say, ‘Oh, my God, I got like, 100 matches.’ And it’s very difficult for [these] men to achieve the same thing.”

Lindner explained, “The way I view male psychology is that there is this kind of machinery that is sensitive to cues pertaining to sexual conflict. When male psychology registers failure in the sexual marketplace, it will often respond aggressively.”

Those responses, Lindner said, become amplified in online forums and chat rooms.

“I posit that hateful online communities allow low-status men to engage in virtual or simulated coalitional bargaining with a sympathetic audience of like-minded others, providing private but futile satisfaction,” Lindner writes. “Existing accounts construe aggression as a response to the perceived failure to live up to male identity, such that aggressive acts [are] intended to ‘repair’ masculinity in the eyes of others.”

Most incels do not commit violent acts, but some have asserted violent domination through mass shootings, Lindner says.

“They are trying to prove their potency, their mattering, their ability to wield power by inflicting harm. This impression of potency could (in an ultimate sense) make them more respected and hence sexually successful,” Lindner writes.

Quoting a 2019 study by Jillian Peterson and sociologist James Densley, co-founders of the think tank The Violence Project, Lindner notes that we can see this type of violence also is connected to a wider cultural shift as, “Twenty percent of all mass shootings in the past 50 years occurred in just the last five years, with more than half of the shootings occurring since 2000 and 33 percent since 2010.”

Incels don’t always select others as their targets, either. Lindner writes they also often turn their anger against themselves — using threats of suicide to regain some form of power and communicate their willingness to go to extremes.

“Like other forms of extremist violence, incel violence thus constitutes more than simply an attack, but an information exchange,” Lindner notes.

She went on to say it’s unclear why the mechanisms at play diverge down the two violent routes and that she is currently in the process of developing an assessment tool that will help identify men who are more at risk of committing “self-directed violence, suicide, or self-harm, versus more outward directed aggression.”

Lindner has accepted a position at the University of Rhode Island to continue her work on evolved male psychology and incels.