Why we may still be choosing our friends like it's the Stone Age
Choosing friends may involve more than clicking with others who share our interests or outlooks. According to new research, people may select friends based on traits that made them valuable survival partners in our evolutionary past.
The standard social psychology view of friendship is that we are strategic in selecting friends, choosing people who can help us achieve our goals. Examples include networking for a job, studying for an exam or finding a roommate.
But this new study, published in the journal Evolution and Human Behavior, argues that friendship evolved as a long-term cooperative partnership critical for survival when humans were hunter-gatherers.
According to this view, we look for traits such as cooperativeness, competence, social status and physical attractiveness, even if those attributes are not directly useful for our current goals. "Friend choices are sometimes goal-relevant and sometimes guided by evolved 'social taste buds,'" the study authors commented in their paper.
Modern goals versus ancient needs
To test whether friendship choices are driven by modern goals or ancient instincts, researchers from the University of California, Santa Barbara, designed two experiments.
In the first, 156 college students were paired with a same-sex stranger in a lab for a 30-minute face-to-face conversation. Afterward, participants privately rated how much they liked the other person as a potential friend and evaluated their traits. They could also decide whether to share their email address with their partner, although addresses were exchanged only if both members of the pair agreed.
Additionally, the researchers measured each participant's strength, including grip strength, chest strength and biceps circumference.
The second study was conducted entirely online and involved 444 volunteers recruited through Amazon Mechanical Turk. Participants were first asked to write down their single most important life goal at that moment. Then, they rated photographs of unfamiliar same-sex faces as potential friends.
Finally, another group rated those same photos on traits such as ancestral productivity (how capable someone looked as a hunter-gatherer), prosociality, social status, physical attractiveness, dominance and other characteristics. This allowed the research team to compare what makes a face seem like a desirable friend with what people said they needed to achieve their current goals.
What we actually look for in a friend
In the first study, researchers reported that participants preferred friends who seemed cooperative, dominant, attractive and of higher social status. Among these traits, cooperativeness, physical attractiveness and dominance emerged as the strongest predictors of friendship interest.
Men were much more likely than women to offer their email address to a potential friend, despite rating their partners as similarly desirable overall.
The results from the second study revealed that the traits that make a face seem like a desirable friend did not consistently match what participants needed to achieve their everyday goals. This supports the evolutionary theory of friendship selection, although the findings do not rule out the possibility that current goals also play a role, as the researchers noted.
"The majority of variance in friend desirability judgments comes from preferences that are not goal-calibrated."
So while we may think we are choosing friends to help us with our modern lives, our ancient instincts may also be calling the shots behind the scenes.
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Publication details
Adar B. Eisenbruch et al, What do people want in a friend? Cues of ancestral cooperative partner value predict same-sex friend preferences, Evolution and Human Behavior (2026). DOI: 10.1016/j.evolhumbehav.2026.106919
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Citation: Why we may still be choosing our friends like it's the Stone Age (2026, July 14) retrieved 14 July 2026 from https://phys.org/news/2026-07-friends-stone-age.html
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