An analysis of online posts suggests that men are more likely to regret missed sexual opportunities while women are more likely to regret engaging in sex and romantic relationships.

The new research, published in Evolutionary Behavioral Sciences, supports the theory that sexual regret functions differently in men and women due to asymmetries in parental investment. While a woman might face nine months of a metabolically-costly pregnancy after having sex, the minimal obligatory investment for a man is almost zero.

The new study consisted of two parts. In the first, the researchers analyzed 61,412 posts from Craigslist’s missed connections section, where people seek to connect with someone they saw briefly in public. In the second, the researchers collected and examined 3,500 posts from FMyLife.com’s love and intimacy sections, where people anonymously post embarrassing confessionals.

“These data were collected over a decade ago. At the time, I was interested in testing theories about human behavior using ‘big data’ from the web, which can sometimes show evidence of behavioral residue,” said study author Gregory D. Webster, a professor of psychology at the University of Florida.

The researchers found that most of the missed connections posts were written by men. There were 42,911 men seeking-women posts but only 18,501 women-seeking-men posts. When it came to embarrassing confessionals regarding love and intimacy, however, the researchers found that women had written more posts than men.

“Men tend to overperceive women’s sexual interest in them, and this relates to men experiencing more regret over missed sexual opportunities than women, on average. Consequently, men are more likely to post missed connections on Craigslist,” Webster told PsyPost.

“Women tend to experience more sexual commission regret than men; they’re more likely to regret dating or hooking-up with men they later wish they hadn’t. Consequently, women are more likely to post embarrassing sexual and romantic confessionals online.”

“The generalizability of the findings is limited to people who visit these websites — craigslist.org and fmlife.com. In other words, there’s likely a selection bias. We can’t know for certain if these results would generalize to broader, more diverse populations, including countries and cultures outside the United States,” Webster added.

“Because we now generate more data—usually online—than we know what to do with, researchers need to think creatively about the questions they can ask about data that already exist in online archives.”

The study, “Missed Connections and Embarrassing Confessions: Using Big Data to Examine Sex Differences in Sexual Omission and Commission Regret“, was authored by Gregory D. Webster, C. Veronica Smith, Tatiana Orozco, Peter K. Jonason, Amanda N. Gesselman, and Rachel Leigh Greenspan.