When “No Strings Attached” Comes with a Personality Profile: A Closer Look at Psychopathy and Casual Sex
Tuesday, June 10, 2025. This is for Viv in Vancouver.
Once again, psychology has put on its lab coat and peered into the bedrooms of the statistically inclined.
A recent study in Sexual and Relationship Therapy examined which personality traits best predict openness to casual sex.
Psychopathy took home the gold.
Narcissism and Machiavellianism sulked off the podium.
And the so-called “Light Triad”—traits like compassion and faith in humanity—barely showed up at the race.
It’s the kind of finding that makes headlines and Tinder profiles, but don’t pour the champagne just yet. There’s a lot to admire in this research—and just as much to question.
Sociosexuality: The Scientific Term for “It’s Complicated”
Psychologists, in their eternal quest to rename things your grandmother already understood, define sociosexuality as a person’s tendency to pursue sex without emotional closeness or commitment. It includes:
Behavior: How often someone’s pants hit the floor outside monogamy.
Attitude: How they feel about it (morally, emotionally, logistically).
Desire: How often they fantasize about strangers, acquaintances, or the ethically ambiguous.
The trait isn’t inherently bad or good. It’s just one of many mating strategies humans employ—right up there with “wait until marriage” and “drunkenly text your ex at 2am because Mercury is in retrograde.”
Enter: The Dark Triad
The study’s researchers wanted to clarify an old hunch: that the so-called Dark Triad traits—narcissism, Machiavellianism, and psychopathy—are linked to casual sex.
And at first glance, they are. All three correlated with higher sociosexuality.
But when the data got statistically scrubbed—regression analysis, control variables, the whole scientific dental cleaning—only psychopathy remained a consistent predictor across behavior, desire, and attitude.
Narcissism? Dropped out like a bored freshman.
Machiavellianism? Vanished like it had a better scheme to run.
So... What Is Psychopathy Doing at the Casual Sex Party?
In this context, psychopathy doesn’t mean serial-killer vibes. Think more along the lines of:
High impulsivity
Low emotional reactivity
A thrill-seeking streak
And a willingness to treat other people’s hearts as optional accessories
People high in psychopathy tend to chase novelty, ignore consequences, and compartmentalize emotion. So yes—it makes sense they’d be statistically more open to uncommitted sex.
But before we start throwing copies of Mating in Captivity at every emotionally avoidant hookup partner, let’s pause.
What the Study Gets Right
This research, led by Betul Urganci at Koç University, has some real strengths:
It cleanly isolates psychopathy as the strongest driver of sociosexual behavior from among the Dark Triad.
It includes both men and women and explores gender differences with care.
It makes a valiant attempt to balance the dark with the light—testing not just antisocial traits, but prosocial ones too.
And it does what good research should: raises questions rather than pretending to answer them all.
But Here’s What It Misses
Reducing Casual Sex to Dysfunction Is… Well, Predictable
Not everyone who enjoys uncommitted sex is emotionally stunted, impulsive, or seeking power through conquest. Some people are just… adults making adult choices. Some are grieving. Some are curious. Some just don’t like brunch.
Framing sociosexuality primarily through the lens of psychopathy risks pathologizing sexual freedom. It’s a tidy headline that overlooks messy realities—grief sex, transition sex, curiosity sex, and yes, even joyful, respectful hookup sex.
Where Are the Cultural Variables?
This study mostly sampled White, heterosexual, partnered adults in the U.S.—via Mechanical Turk, no less. So when we say “psychopathy predicts casual sex,” we’re really saying: “Among mostly straight people with internet access and spare time, certain traits predict certain survey answers.”
Cross-cultural studies show vast variation in sociosexuality. In some collectivist cultures, shame regulates behavior more than personality does. In others, norms about autonomy or religion shape sexual strategy. That missing layer is crucial.
The Light Triad Deserves Better
The researchers also tested the “Light Triad”—traits like Kantianism (best summarized as treating others as ends in themselves, not means to an end), Faith in Humanity, and Humanism. Unsurprisingly, these traits weren’t linked to a high desire for casual sex.
But here’s the twist: they also weren’t strongly linked to a low desire for it, either.
Once the Dark Triad traits were controlled for, most Light Triad traits became statistical wallflowers. This doesn’t mean kind people are ambivalent about hookups—it might mean the model isn’t capturing what “kindness in mating” looks like.
Light Triad folks might engage in casual sex, but with clearer communication, more aftercare, or better boundaries. The absence of correlation doesn’t mean absence of influence—it might just be subtler, and less sexy to measure.
The Usual Suspects: Self-Report and Sample Bias
As always, self-report studies rely on people knowing themselves, telling the truth, and interpreting survey questions in roughly the same way. That’s a lot to assume in a population that routinely lies about flossing.
And while Mechanical Turk is convenient, it skews toward certain education and income levels. It’s not a bad tool—but let’s not confuse this convenience of sampling with global truth.
Final Takeaway: Useful, But Use With Care
Yes, psychopathy is linked to casual sex—but that’s only part of the story.
Personality traits do shape sexual behavior, but so do culture, opportunity, trauma, neurodiversity, attachment style, gender roles, and the entire licentious library of human longing.
This research perhaps adds a useful brick to the wall—but we’re still building the house.
But here is my take, gentle reader. If you’re a therapist, don’t assume the client who avoids intimacy is a “Dark Triad case.”
And if you’re dating someone who prefers casual sex, don’t assume they’re emotionally bankrupt. Ask better questions. People are complicated. That’s why we keep studying them.
Not every emotionally detached person is a psychopath—some are just bad at texting.
Be Well, Stay Kind, and Godspeed.
References
Urganci, B., Sevi, B., Dogruyol, B., & Sakman, E. (2024). Examining the role of Dark and Light Triad traits on sociosexuality. Sexual and Relationship Therapy. https://doi.org/10.1080/14681994.2024.0000000
(Note: Replace with actual DOI when available.)
Jonason, P. K., Li, N. P., & Buss, D. M. (2010). The costs and benefits of the Dark Triad: Implications for mate poaching and mate retention tactics. Personality and Individual Differences, 48(4), 373–378. https://doi.org/10.1016/j.paid.2009.11.003
Jonason, P. K., Webster, G. D., Schmitt, D. P., Li, N. P., & Crysel, L. (2012). The antihero in popular culture: Life history theory and the Dark Triad personality traits. Review of General Psychology, 16(2), 192–199. https://doi.org/10.1037/a0027914
Kaufman, S. B., Yaden, D. B., Hyde, E., & Tsukayama, E. (2019). The Light vs. Dark Triad of personality: Contrasting two very different profiles of human nature. Frontiers in Psychology, 10, 467. https://doi.org/10.3389/fpsyg.2019.00467
Penke, L., & Asendorpf, J. B. (2008). Beyond global sociosexual orientations: A more differentiated look at sociosexuality and its effects on courtship and romantic relationships. Journal of Personality and Social Psychology, 95(5), 1113–1135. https://doi.org/10.1037/0022-3514.95.5.1113
Seto, M. C., & Lalumière, M. L. (2010). What is so special about male adolescent sexual offending? A review and test of explanations through meta-analysis. Psychological Bulletin, 136(4), 526–575. https://doi.org/10.1037/a0019700