Psychologist John Gottman can observe a married couple for fifteen minutes and predict with 95 percent accuracy whether they will divorce within five years.

How does he do it? Body language? Eye contact? Whether or not they hold hands? Nope. He listens to what they say to each other, and then counts the ratio of positive to negative comments. That’s it. Couples with fewer than five positives for every negative are headed for disaster.

For a truly good marriage, the ratio needs to be 20 positive comments for every negative one.

Businesses are like marriages in this way. Focus on maintaining a good 5-to-1 ratio with customers and colleagues, or disaster looms. And if you want truly great relationships in your business—and who doesn’t?—aim even higher, for 20-to-1.

This might be hard to do at first if you work in a particularly negative workplace. But that’s also where the opportunity is, because a positive comment stands out in the muck, shining like a beacon of hope. Start simple. A colleague has a new haircut, and you say, “Hey Peg, I like your hair!” Then develop the practice of finding and commenting on positive performance. When someone turns in a report that’s always on time, say, “Hey Bob, thanks for always getting these to me on time. That really helps.” Maybe this is the only thing Bob ever does right. I don’t care. That positive comment can be the beginning of a tide that lifts all boats for Bob.

That doesn’t mean you can’t or shouldn’t offer constructive criticisms. Standards plummet when you do that. But make an effort to leaven it with praise.

One of the best results of this injection of sunshine is that it’s entirely contagious. Make a note of the day the positive wave you started comes back to you.