Here's an easy way to measure the quality of your relationship

If you want to know how good your relationship is, ask yourself: How much do you laugh together?

Couples who laugh together reported higher quality relationships, in a study published in Personal Relationships this August.

The researchers, from the University of North Carolina at Chapel Hill, recorded 71 heterosexual couples telling the story of how they first met. They then counted how many times the couple laughed, and whether they were laughing together or alone.

Couples who laughed together more reported having higher quality relationships, defined by their feelings of closeness and support.

The laughs also exposed some gender differences. Of the nearly 1,400 laughs the researchers recorded, 62% of them came from the women.

But men's laughs were more likely to be contagious, causing their female partner to laugh with them. And this reciprocation had a special effect on the men.

"The greater the duration of shared laughter in the lab, the higher the men's ratings of commitment, satisfaction, and passion toward their partners," lead study author Laura E. Kurtz, a graduate student, told Tech Insider. "These findings suggest that there may be something especially potent about shared laughter for men."

The sample size of 71 couples is too small to know whether there's a similar effect in the general population, but Kurtz said previous research supports this association.

She also told us that she suspects "that shared laughter may play a causal role in promoting [high quality] relationships," though this study showed only a correlation.