Tell a woman you volunteer regularly, and she'll probably find it attractive. Flickr/State Farm Scores of psychological studies suggest that, for guys, attractiveness isn't just about the way you look.

From being a talented musician to walking a dog, there are plenty of traits and behaviors that can amp up your sex appeal to women — especially if you're looking to land a long-term relationship.

A growing body of research on romantic attraction has focused on the importance of altruism: Men who display helping behaviors are generally perceived as more attractive than those who don't.

In a 2013 study on the topic, researchers had young, heterosexual men and women rate pictures of other men and women on how attractive they would be for short- and long-term relationships.

Some of the people pictured were said to engage in altruistic behaviors, such as volunteering at a homeless shelter. Other people pictured were described in neutral ways, such as "loves Chinese food."

Both men and women rated the altruistic people as more attractive for long-term relationships — but women showed a stronger preference for altruism than men did.

More recent research suggests that altruism could be even more appealing than good looks.

In a study published this year, researchers looked exclusively at heterosexual women's preferences for attractiveness and altruism in men.

About 200 women were asked to look at photographs of men's faces. Half those faces had been determined to be extremely physically attractive; the other half had been determined to be extremely physically unattractive.

The women saw two pairs of faces at a time, one attractive and one unattractive.

Each pair of faces was displayed alongside a description of a scenario and how each man behaved. For example: "two people are walking through a busy town and see a homeless person sitting near a cafe." One man goes into the cafe and buys a sandwich and tea for the homeless person; the other man pretends to use his cellphone and walks straight past the homeless person.

All the women were asked to rate each man on how attractive he was for a short- or long-term relationship.

The researchers walked away with several key findings.

First, as previous research had found, altruistic men were more attractive than nonaltruistic men.

Second, altruistic men were more attractive for long-term than short-term relationships. When it came to short-term relationships, nonaltruistic men were in fact more desirable than altruistic men.

Perhaps the most striking finding was that altruism appeared to be even more appealing than physical attractiveness when it came to long-term relationships. Unattractive men high in altruism were rated more attractive for long-term relationships than attractive men low in altruism.

It's hard to say whether these study findings apply to real-life interactions. But they do suggest that, if you're a man looking for a committed relationship with a woman, you shouldn't hesitate to flaunt the fact that you're an unpaid mentor for elementary-school kids or that you help your elderly neighbor buy groceries every week.

It could be an easy way to gain an edge over the more self-oriented guys out there.