If you’re happy and you know it, tell someone. Unless that person’s having a bad day and you don’t want to rub it in.

A new study from researchers in New Zealand and the United States suggests that people’s ability to express positive emotions is tied to their risk for heart disease.

In the study, participants took a test of their ability to express positive emotions with facial expressions. They also had their blood drawn, and their risk for cardiovascular disease was assessed based on their blood results, lifestyle and demographics.

It turned out there was a correlation between people’s heart health and their skill in expressing happiness. People who were more adept at communicating happiness through their body language also tended to be at lower risk for heart disease. The link was especially strong in men.

Previous research has linked facility in expressing positive emotions to workplace social effectiveness. For example, a 2013 study found that expressing authentic positive emotions helped people meet their goals in workplace social interactions.

The same study looked at whether exaggerating positive emotions would have similar benefits. It found that playing up positive emotions too much doesn’t help in workplace interactions with colleagues. On the other hand, it did turn out that “amplifying felt positive emotions promoted goal attainment … in interactions with superiors,” which is basically research speak for “brown-nosing works.”

Of course, there are some situations where being able to suppress positive emotions comes in handy too. Studies have found that when people suppress displays of happiness after outperforming others in competitive situations, they tend to be viewed more positively and have an easier time making friends.

Which leads us back to the apparent rule of thumb for showing positive emotions: in general, expressing happiness is associated with a range of benefits from better heart health to workplace social success – except when being upbeat means lording it over others, in which case playing it cool is the way to go.

Image: Flickr/Asad Durrani