Whether you’re on your first date or you’ve been married for ages, forthcoming research in the Journal of Positive Psychology says there’s one character trait that’s essential for a solid relationship: humility.

In one study, researchers asked participants to look over fake dating profiles and rate which ones they’d be most likely to date, based on their perceived likability, friendliness, number of friends, fun, and attraction. Some of the profiles were written to seem more humble, and others to seem less humble.

Across the board, respondents rated the humble profiles significantly higher than the haughty ones—regardless of the other qualities.

Beyond first-impressions, researchers also found that humility was key in maintaining long-term relationships. In a separate study, researchers surveyed over 400 participants about forgiveness in their relationships.

One thing they found was that couples reported more forgiveness if they were in long-distance relationships versus proximal relationships). Another (more relevant) finding: couples with humble partners also reported more forgiveness than those without much humility between the two of them.

This isn’t a signal that you should be completely self-effacing all the time (not to mention, other research suggests that it can be attractive to talk yourself up on a first date). But this is a good reminder that when it comes to keeping your relationship strong, staying humble and grounded is the smartest approach.

One simple way to accomplish that: get used to saying the words “you were right” when applicable. Admitting when you were wrong (and apologizing quickly and sincerely for your mistakes) shows humility, and can do wonders for your bond.

Another way: showing gratitude toward your partner.