Growing up, many men were taught one thing: women love bad boys. When it comes to this cultural phenomenon, the bad boy is a liberator, a loner, a sexual deviant, and a timeless icon. But, according to recent study published in the journal Evolutionary Psychology, women find men who are altruistic more desirable than those who catch the eye when it comes to long-term relationships.

In their new study, researchers from the University of Worcester provided further evidence of the importance of altruism in women's dating choices. Selflessness is seen as "a highly important characteristic trait women look for in long-term partners," lead author Daniel Farrelly wrote in the article.

To observe how altruism influenced physical attractiveness, over 200 straight women in their early 20s were recruited online. The women were shown 12 sets of photographs that showed the faces of two men — a handsome man and a less attractive one — each labeled with a letter. Each of the images was given one of eight scenarios that involved the one of two men being altrusitic, while the other wasn't. Some scenarios attributed the altruistic behavior to the handsome man, while others favored the less handsome one. Other photo pairings featured both men partaking in neutral behavior. The goal of the study was to determine how essential looks are when men are described in similar terms.

 For example, one scenario read: "Two people are walking through a busy town, and notice a homeless person sitting near a cafe. Person E decides to go into the cafe to buy a sandwich and a cup of tea to give to the homeless person outside. Person F pretends to use his mobile phone and walks straight past the homeless person."

After scanning the photos and reading the scenarios, the women were asked to rate (on a scale of 1 to 5) how attractive the men were for engaging in a brief affair or a long-term relationship.

As expected, the altruistic men were rated as more attractive than non-altruistic men for long-term relationships, with the average desirability score of 3 compared to 2.1. The physically attractive men, with an average desirability score of 2.8, were unsurprisingly seen as more appealing than less handsome men, who only scored 2.2. And finally, self-absorbed men were viewed as more attractive for a one night stand, while the altruistic men were rated as more desirable for long-term relationships.

"Being both attractive and altruistic made a man more desirable than just the sum of the two desirable parts," wrote the researchers. In other words, a handsome guy who climbs up a tree to save a cat will increase his desirability, and therefore draw more women.

Farrelly emphasizes the need for further research to examine the effect altrustic women have on men's desirability rating. Currently, with this area of research, most studies solely focus on women's ratings. 

In a similar 2008 study, researchers analyzed how altruism affects women's dating selection. Participants answered questions about various qualities they might seek in a partner, including nine examples of altruistic behavior, such as "donates blood regularly," "volunteered to help out in a local hospital," and "once cared for a stray dog." The findings revealed women place a greater importance on selflessness than previously believed.

This altruistic behavior translates into a propensity to reciprocate, or an attitude where "you scratch my back and I'll scratch yours." In the dating pool, this signals the man will be selfless and caring. So, if you're single, volunteering at the soup kitchen may help you snag a couple of quality dates.

Sources: Farrelly D, Clemson P, and Guthrie M. Are Women’s Mate Preferences for Altruism Also Influenced by Physical Attractiveness? Evolutionary Psychology. 2016.

Ferguson E, Farrell K, and Lawrence C. Blood donation is an act of benevolence rather than altruism. Health Psychology. 2008.