"Compassionate love" includes small, random acts that add up to bigger happiness in marriage. It's a skill set that increases marriage longevity and satisfaction, studies say. It also applies to both genders, because men really aren't from Mars nor women from Venus.

It turns out they are all earthlings — and more alike than you might think, according to research from the University of Rochester that was published in the Journal of Personality and Social Psychology.

Compassionate love has been getting a lot of attention in news articles and books recently. Writes Wall Street Journal columnist Elizabeth Bernstein, compassionate love is "recognizing a partner's needs and concerns and putting them ahead of your own."

Examples might include anything from warming a partner's side of the bed to scraping ice off the windshield of a partner's car, or from making a favorite dish to a gentle touch as you pass each other in the hallway.

"It's not just making people feel good," Harry T. Reis, a University of Rochester professor of psychology, told Bernstein. "It's a way of communicating to the other person that you understand what they are all about and that you appreciate and care for them."

Reis has been studying 175 American newlywed couples since 2009, focusing on how they show compassion in their marriages. He told Bernstein those who master compassionate love have happier marriages. And it's not just nice, but needed. When acts of kindness and concern no longer mark a marriage, that union is likely in trouble.

A book called "The Science of Compassionate Love" outlines cutting-edge research on the topics of altruism and compassionate love and recommends its expression in many relationships, from the most intimate to interactions with strangers. There's so much interest in the topic right now that ongoing research projects range from using the technique to promote longevity for those with AIDS to bolstering parent-teen relationships, among others.

Reis, who is an expert on compassionate love, has also looked hard at gender differences in his research.

In the Mars-Venus study, the researchers looked at 122 different characteristics involving 13,301 individuals. They found that men and women really aren't that dissimilar.

"In other words," reads a statement about the study, "no matter how strange and inscrutable your partner may seem, their gender is probably only a small part of the problem."

It's not that unusual, for instance, for women to be good at math and men to be empathetic, despite stereotypes to the contrary, said lead author Bobbi Carothers, who completed the Venus-Mars study as part of her doctoral dissertation at Rochester. She's now a senior data analyst at Washington University in St. Louis.

"Sex is not nearly as confining a category as stereotypes and even some academic studies would have us believe," she said.

Carothers and Reis looked at 13 earlier studies and also collected their own data on multiple psychological indicators, including what they called the "big five" personality traits: extroversion, openness, agreeableness, emotional stability and conscientiousness. They found few things they could categorize as being feminine or masculine. The genders vary on anthropologic measures, like strength and and waist-to-hip measures. And "gender can be a reliable predictor for interest in very stereotypical activities, such as scrapbooking and cosmetics (for women) and boxing and watching pornography (for men)," they said.

But most measures show little difference. And those who fit stereotypes on one measure did not usually fit it on another.

"Masculinity is a spectrum and there are men who are more 'woman' than women in terms of 'female characteristics' such as empathy and compassion," Dr. T. Byram Karasu, chief psychiatrist at Montefiore Medical Center in New York City, told the Courier-Journal. "Femininity is also a spectrum. On one end, some females have more testosterone and aggression than most men."

Asked why the genders are usually depicted as being in such separate worlds, he replied, "It is the drama that we love. These are the roles we are given to play."

But playing those roles can be harmful, according to researcher Reis. He told the newspaper that "it would make me very happy (if people started seeing) these various qualities as human differences — qualities that some people have more of and some people have less of — and that a person's gender is a very small piece of that."

They did note, though, that in countries and cultures where gender roles are more prescriptive, like Saudi Arabia, the findings may be very different.

EMAIL: lois@desnews.com,