Science of Sex
Casual sex has been on the rise for decades. This has been concerning to some people for various reasons. Some scientific studies may present a different view than many expect.
Research suggests a majority of people who engage in casual sex actually hope those encounters will lead to something more lasting. One study of 500 college students found that 65% of women and 45% of men reported hoping their most recent hookup would develop into a committed relationship (Owen & Fincham, 2011).
For those who are naturally and genuinely inclined toward casual sex, engaging in it is associated with lower depression and anxiety and higher self-esteem and life satisfaction. Those who are not naturally inclined toward casual sex tend not to experience the same benefits (Vrangalova & Ong, 2014).
These are the positives, and there are clearly some negatives. Regret and shame are two emotional possibilities, and unwanted pregnancies and sexually transmitted infections are also serious risks.
The studies Estupinyà (n.d.) references indicate a few things in need of further investigation. To start, it does sound as though many people are looking for steady relationships, even though they may engage in a “casual” encounter without that in mind.
Is this the healthiest and most effective strategy for initiating a long-term relationship? I believe most of us would assume the answer is no, but it is an empirical question. Perhaps it saves time.
Or perhaps there is a breakdown in our current socialization for us to understand what we really desire, e.g., a long-term relationship, and/or we don’t know how to communicate about that, so instead we end up in casual encounters. Perhaps developing greater self-awareness and effective communication skills could reduce casual encounters, while increasing the number of healthy long-term relationships if that is the goal.
In any event, we have a lot to learn, and I hope we do it quickly, about how changes in the media are impacting our sexual and relationship behaviors.
The Full Picture: What Peer-Reviewed Science Actually Tells Us
The cultural assumption about casual sex is pretty consistent: it is emotionally empty at best and psychologically damaging at worst, particularly for women. Movies, advice columns, and even some clinicians reinforce this framing. And for some people, under some circumstances, that is accurate.
But peer-reviewed science tells a more complicated, and ultimately more useful, story.
This is not a case for or against casual sex. It is an effort to look honestly at what the research actually shows, because the variables that predict whether a casual encounter is good or bad for mental health are not the ones most people assume.
What a Major Systematic Review Found About Casual Sex and Emotional Health
Start with the most comprehensive evidence available. A systematic review of over 70 studies on the emotional outcomes of casual sexual relationships and experiences found that, on balance, people reported more favorable than unfavorable emotional outcomes. Commonly reported benefits included gains in self-esteem, reduced stress, increased relaxation, and positive mood (Wesche et al., 2021).
That surprises most people. It surprised researchers too.
To be clear, the same review documented negative outcomes as well: regret, shame, anxiety, and depressive symptoms were all present in the literature. The finding is not that casual sex is good. The finding is that it is not uniformly bad, and the factors that predict whether it goes well or badly are identifiable. That is a more useful conclusion, and it is where the real conversation begins.
New Research: Singles Who Have Casual Sex Report Fewer Depressive Symptoms
A 2025 study published in Personal Relationships examined two independent samples of single adults and found that those who were sexually active reported lower attachment avoidance, greater sexual satisfaction, and a higher sense of their own mate value compared to sexually inactive singles. In the second of the two samples, sexually active singles also reported lower depressive symptoms and higher life satisfaction, though the authors note these differences were not consistent across both samples and warrant further investigation (Amarakoon et al., 2025).
This does not mean casual sex is the prescription for depression. It means the blanket warning against casual sex obscures real individual variation that clinicians and individuals alike need to understand.
Casual Sex vs. Committed Sex: Is There Really a Mental Health Gap?
Here is another finding that challenges the conventional narrative. A study of college students across 30 U.S. institutions found almost no significant differences in self-esteem, life satisfaction, or psychological wellbeing between those engaging in casual sex and those in committed sexual relationships (Bersamin et al., 2014). A separate study examining friends-with-benefits relationships found similarly nuanced results, with outcomes depending heavily on the expectations each person brought to the encounter (Eisenberg et al., 2009).
The absence of a reliable wellbeing gap between casual and committed sexual activity is not an argument for casual sex. It is an argument against the oversimplified idea that relationship context alone determines psychological outcome. If that were consistently true, the gap would show up reliably in the data. It does not.
Why Your Reason for Having Casual Sex Matters More Than the Act Itself
This is perhaps the most practically important finding in the literature.
Vrangalova (2015) applied Self-Determination Theory to the question of casual sex and wellbeing in a longitudinal study. The key variable was not whether someone had casual sex. It was why.
Non-autonomous motivation, meaning sex driven by intoxication, social pressure, insecurity, or avoidance of negative feelings, predicted worse psychological outcomes. Autonomous motivation, meaning sex that was freely chosen and aligned with the person’s own values, was not associated with long-term negative effects on wellbeing (Vrangalova, 2015).
A related study found that sociosexually unrestricted individuals, those who are naturally and genuinely oriented toward casual sexual activity, reported higher wellbeing after casual sex compared to periods without it, while no such pattern emerged for those less oriented toward casual sex (Vrangalova & Ong, 2014).
In clinical terms, this reframes the question entirely. It moves from “did you do it” to “did you actually want to, and were you honest with yourself about it?” That is a question about self-awareness, values, and agency, which also happens to be exactly the kind of question that brings high performers into coaching and therapy, usually about something other than sex, but the underlying dynamic is identical.
The gap between what you say you want, what you actually do, and why you do it shows up in every domain of life. Relational decisions are not exempt.
Casual Sex Can Boost Self-Esteem and Sexual Confidence, Under the Right Conditions
Research consistently links sexual satisfaction to self-esteem gains at both the between-person and within-person level. A multilevel meta-analysis found meaningful bidirectional associations between self-esteem and sexual health across multiple domains, with positive sexual experiences contributing to improved self-evaluation regardless of relationship context (Sakaluk et al., 2020). A longitudinal study of over 11,000 adults confirmed reciprocal within-person transactions between self-esteem and sexual satisfaction over time, with each influencing the other (Weber et al., 2026).
The practical implication: sexual experience is not emotionally neutral. Positive encounters can provide a genuine boost to confidence and self-perception. Whether that upside is realized depends on the person’s readiness, values alignment, and the specific circumstances surrounding the encounter.
When Casual Sex Can Hurt: Risk Factors That Tip the Scale
The same systematic review that documented generally positive emotional outcomes also identified clear conditions under which casual sex predicts worse psychological results. Alcohol and drug involvement, prior psychological distress, insecure attachment styles, and encounters with strangers rather than known partners were all associated with significantly higher rates of negative emotional outcomes (Wesche et al., 2021).
A longitudinal study of adolescents found that psychological consequences were substantially more negative when alcohol was involved, when the person had prior emotional difficulties, or when the encounter conflicted with their personal values (Dubé et al., 2017).
These are not abstract risk factors. They are the same variables that predict poor outcomes across a wide range of impulsive or avoidance-driven behaviors. Substance involvement reduces autonomous decision-making. Prior distress increases vulnerability. Values misalignment produces internal conflict afterward. None of this should be surprising, but it is worth stating directly.
Reason and Intent, Not the Act
Taken together, the research leads to a clear conclusion that is, paradoxically, more demanding than a simple prohibition or a blanket endorsement.
Casual sex is not inherently harmful to mental health. The outcome is shaped by motivation, emotional readiness, prior psychological functioning, partner familiarity, and alignment with one’s own values. Those variables, not the behavior itself, are what matter.
What this means in practice: the most important predictor of how any sexual encounter lands psychologically is your internal starting point. Are you clear on what you actually want? Are you acting from your values or despite them? Are you using alcohol or social momentum as a substitute for honesty? Is this aligned with what you want for your relational life?
Those are questions about self-awareness and communication. And if the research on casual sex teaches us anything beyond the specific behavior, it is this: knowing yourself clearly enough to act from that knowledge, in any domain, consistently produces better outcomes.
Whether in a difficult conversation, a major decision, or a relational choice made at midnight, the skill set is the same. Clarity about what you want. The capacity to pursue it honestly. Both are trainable. And both matter more than most people have been led to believe.
References
Amarakoon, I., et al. (2025). Who is “doing it”? Casual sex and wellbeing in singlehood. Personal Relationships. https://doi.org/10.1111/pere.70045
Bersamin, M. M., Fisher, D. A., Walker, S., Hill, D. L., & Grube, J. W. (2014). Risky business: Is there an association between casual sex and mental health among emerging adults? Journal of Sex Research, 51(1), 43-51. https://doi.org/10.1080/00224499.2013.772088
Dubé, S., Lavoie, F., Blais, M., & Hébert, M. (2017). Consequences of casual sex relationships and experiences on adolescents’ psychological well-being: A prospective study. Journal of Sex Research, 54(8), 1006-1017. https://doi.org/10.1080/00224499.2016.1255874
Eisenberg, M. E., Ackard, D. M., Resnick, M. D., & Neumark-Sztainer, D. (2009). Casual sex and psychological health among young adults: Is having “friends with benefits” emotionally damaging? Perspectives on Sexual and Reproductive Health, 41(4), 231-237. https://doi.org/10.1363/4123109
Estupinyà, P. (n.d.). Calling it sex when they mean love. Scientific American. https://www.scientificamerican.com/blog/mind-guest-blog/calling-it-sex-when-they-mean-love/
Garcia, J. R., Reiber, C., Massey, S. G., & Merriwether, A. M. (2013). Sexual hookup culture: A review. Review of General Psychology, 16(2), 161-176. https://doi.org/10.1037/a0027911
Owen, J., & Fincham, F. D. (2011). Young adults’ emotional reactions after hooking up encounters. Archives of Sexual Behavior, 40(2), 321-330. https://doi.org/10.1007/s10508-010-9652-x
Sakaluk, J. K., Kim, J., Campbell, E., Baxter, A., & Impett, E. A. (2020). Self-esteem and sexual health: A multilevel meta-analytic review. Health Psychology Review, 14(2), 269-293. https://doi.org/10.1080/17437199.2019.1625281
Vrangalova, Z. (2015). Does casual sex harm college students’ well-being? A longitudinal investigation of the role of motivation. Archives of Sexual Behavior, 44(4), 945-959. https://doi.org/10.1007/s10508-013-0255-1
Vrangalova, Z., & Ong, A. D. (2014). Who benefits from casual sex? The moderating role of sociosexuality. Social Psychological and Personality Science, 5(8), 883-891. https://doi.org/10.1177/1948550614537308
Weber, E., Hopwood, C. J., Denissen, J. J. A., & Bleidorn, W. (2026). Self-esteem and sexual experiences. Personality and Social Psychology Bulletin, 52(2). https://doi.org/10.1177/01461672241257355 (First published online September 18, 2024)
Wesche, R., Claxton, S. E., & Waterman, E. A. (2021). Emotional outcomes of casual sexual relationships and experiences: A systematic review. Journal of Sex Research, 58(8), 1069-1084. https://doi.org/10.1080/00224499.2020.1821163