Everybody wants to be happy.

That’s why the science of happiness has gained more attention in recent years —researchers have started to produce reports on happiness around the globe, and positive psychology, which focuses on what makes individuals and communities thrive, has skyrocketed in popularity.

At this point, we actually know a fair amount about how certain behaviours, attitudes, and choices relate to happiness, though most research on the topic can only find correlations.

Researchers think that roughly 40 percent of our happiness is under our own control; the rest is determined by genetics and external factors. That means there’s a lot we can do to control our own happiness.

Here are nine happiness-promoting behaviours backed by science.

1. Relationships are essential. A major study followed hundreds of men for more than 70 years, and found the happiest (and healthiest) were those who cultivated strong relationships with people they trusted to support them.

3. But it helps to have enough money to pay the bills. People’s well-being rises along with income levels up to an annual salary of about $75,000, studies have found. (That number probably varies depending on your cost of living, however.)

4. It’s worth stopping to smell the roses. People who slow down to reflect on good things in their lives report being more satisfied.

5. Acts of kindness boost the mood. Give your friends a ride to the airport or spend an afternoon volunteering. Some research has shown that people who perform such acts report being happier.

6. Breaking a sweat is about more than burning calories. Studies show that increased levels of physical activity are connected to higher levels of happiness. Exercise tends to help mitigate the symptoms of some mental illnesses as well.

Sources: American Psychological Association, BMC Public Health

7. Fun is more valuable than material items. People tend to be happier if they spend their money on experiences instead of things. Researchers have also found that buying things that allow you to have experiences — like rock climbing shoes or a new book to read — can also increase happiness.