New research provides evidence that women who are more comfortable with casual sex that does not include love or commitment tend to be more attracted to positive genetic traits in short-, but not long-term, partners.

The study, published in the journal Personality and Individual Differences, was based on the the dual-sexual strategy hypothesis, which holds that women optimize their evolutionary fitness by seeking different men for short- and long-term relationships.

“People’s sexual preferences are not random,” remarked study author Naomi K. Muggleton of the University of Warwick. “For instance, the attributes heterosexual women find sexy (‘tall, dark, and handsome’) signal that this is a man with good genes, whose children will be fit and healthy.”

“Similarly, men who are emotionally warm, secure, and high in status signal that they can offer emotional and material support to children. A smart strategy is to favour good genes (sexy) men for one-night stands, and men with material prospects (warm, wealthy) when choosing a husband.”

“However, women differ in their sexual experience. We wanted to know if women who were more sexually unrestricted use their past experience to pick this smart strategy.”

In the study of 459 women from India and the USA, the participants were provided “Mate Dollars” that could be used to buy traits to construct their ideal short- and long-term partners. The researchers found that more sexually unrestricted women displayed more distinctive short- and long-term mate preferences.

“Women who were sexually unrestricted were better at differentiating between those sexy traits, which have the highest payoff in a one-night stand, and material traits, which have the highest payoff in marriage,” Muggleton explained.

“For sexually unrestricted women, the type of man she wants to have a fling with is very different from the type of man she ultimately wants to marry. However, women who are more sexually restricted want a one-night stand who is similar to her ideal husband.”

For short-term partners, women who agreed with statements like “sex without love is OK” were more likely to choose genetic traits like masculine, good body, athletic, and good voice over material traits like considerate, patient, high social status, and good income.

“This research doesn’t directly measure what causes the difference between restricted and unrestricted women,” Muggleton noted. “However, a follow-up study (not reported here) finds evidence that more conservative women have a long-term relationship bias. This means that these women find it difficult to imagine themselves having a one-night stand.”

The study, “Unrestricted sexuality promotes distinctive short- and long-term mate preferences in women“, was authored by Naomi K. Muggleton and Corey L.Fincher.