Couple making heart with their hands

Photo by Kristina Litvjak on Unsplash

DAVIS, Calif. — What turns a small crush into a relationship? There is no simple answer to solving wonders of the heart, but scientists have taken a crack at decoding what makes people move from casual to committed partners.

The study by researchers at the University of California, Davis had 208 heterosexual college students at a midwestern university answer a survey about their dating habits, likes and dislikes, as well as attraction to potential partners in the past seven months. On average, students reported having about five crushes, with 15% escalating into relationships. About 7,000 reports were collected on the potential partners.

The million dollar question: What was the deciding factor to go ahead and pursue a relationship with one of these crushes? To answer this question, study authors used machine-learning approaches to select the strongest predictors of romantic interest in each crush. Machine learning relies on algorithms and statistical models to analyze patterns and data. Using the data, the computer draws inferences at common predictors for a romantic relationship.

“What took us by surprise is that many of the important factors were the same things you would have seen in a committed relationship,” explains lead author Paul Eastwick, a psychology professor, in a university press release. “This supposed hookup melee actually looks a lot like people taking relationships for a test run.”

‘Sexual and emotional attraction go hand-in-hand even before relationship materializes’

The difference between a fleeting crush and a potential soulmate were indicators of attachment. A person seemed more likely to have a continued romantic interest in their partner if they wanted to spend time with them often, felt distressed when separated, and enjoyed sharing their daily wins and successes. The study authors suggest these are the defining markers of a pair-bonded relationship.

“When feelings of attachment and emotional connection start to kick in, young adults seem to take it as a sign that this is a crush worth pursuing,” says co-author Samantha Joel, an assistant professor of psychology at Western University. “Sexual and emotional attraction seem to go hand-in-hand, even before a committed relationship materializes.”

There were other factors that helped to form an initial crush, but these did not mean much into forming a romantic pursuit of the person. One variable was physical attractiveness, though it did help in making a good first impression. To test the role of attractiveness, participants uploaded a photograph of their crushes where a separate group of coders, who had no knowledge of the people in the pictures, rated how physically attractive the crushes were from a 1-10 scale. As it turns out, objective physical attractiveness did not amount to much in being romantically interested in someone.

“If we had been looking at a bar, or speed-dating—a setting where you have to compete to be noticed—these coder ratings of physical attractiveness should have been exceptionally good at predicting which partners were highly desired and which ones were not,” explains Eastwick. “But that isn’t what the data revealed at all.”

Study authors suggest relationship development is all about finding someone who is compatible to you. “It isn’t about fighting to get the ‘most valuable’ partner you can,” adds Eastwick. “It’s about trying to find someone who inspires both a sexual and emotional connection. That’s how young people initiate relationships.”

The study is published in The European Journal of Personality.

About Jocelyn Solis-Moreira

Jocelyn is a New York-based science journalist whose work has appeared in Discover Magazine, Health, and Live Science, among other publications. She holds a Master's of Science in Psychology with a concentration in behavioral neuroscience and a Bachelor's of Science in integrative neuroscience from Binghamton University. Jocelyn has reported on several medical and science topics ranging from coronavirus news to the latest findings in women's health.

Our Editorial Process

StudyFinds publishes digestible, agenda-free, transparent research summaries that are intended to inform the reader as well as stir civil, educated debate. We do not agree nor disagree with any of the studies we post, rather, we encourage our readers to debate the veracity of the findings themselves. All articles published on StudyFinds are vetted by our editors prior to publication and include links back to the source or corresponding journal article, if possible.

Our Editorial Team

Steve Fink


Chris Melore


Sophia Naughton

Associate Editor

1 Comment

  1. Roger says:

    I agree completely.