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Did you miss Diversity Day a few months back? It falls each year on May 21, and is formally designated by the United Nations as “World Day for Cultural Diversity for Dialogue and Development.” Personally, I always celebrate the day. I have a cake, and sometimes even a party.

Admittedly, that date also happens to be my birthday. And in truth, I am not sure I’d mark the day with festivities if it weren’t my birthday: Do we really need the UN to urge us to go out and celebrate diversity? Few people could disagree with the value of diversity, but somehow, the bureaucratic hectoring makes it seem a bit spinach-y: good for us but not very enjoyable. A better way to think about diversity, in my view, is how it can make us happier every day.

The truth is that diversity is indeed very good for us, both as a society and as individuals. Useful research has shown that connections forged among different groups of people—what social scientists call “bridging social capital”—reliably enhances peace, prosperity, and social progress. Unfortunately, to seek out such connections goes against many of our instincts, which are to find comfort in the familiar. Not only that, but some of the most beneficial kinds of diversity, such as encountering variety in values and attitudes, are the hardest to pursue and adopt. With a bit of knowledge and practice, however, we can all get better at it—and get happier as a result.

One of the most common findings in the research on friendship is that humans have a strong homophily bias—that is, they prefer to hang around people who are like themselves. This is broadly true for attitudes and values, personality, and demographics such as race, age, education, job, and gender. This bias undoubtedly has its roots in evolution. Those similar to us are more likely to be kin or clan. As several scholars have argued, similarity makes communication easier and facilitates trust, and improves our ability to predict others’ behavior. In short, homophily probably kept your ancestors safer, and still today can lower the mental and emotional effort of dealing with other people.

[Arthur C. Brooks: Don’t avoid romance]

But like so many things that make life more comfortable in the near term—say, sitting on the couch and watching TV instead of going to the gym—homophily bias is suboptimal in the long run. Doing the work to increase the diversity of your relationships can increase well-being, improve certain types of performance, and enhance social adeptness. For example, in studies looking at cross-group friendship among college students, scholars have found that greater diversity increases academic and social skills and improves satisfaction with college. Even among children, diverse friendships are beneficial: One 2011 study showed that in racially and ethnically diverse elementary-school classrooms, children who had more diverse friendships felt less ignored and less socially excluded.

When we think about making more diverse friendships, we usually think of racial or ethnic differences. This is definitely beneficial, but that definition of diversity actually tends to be the easier kind for many people. As the psychologist Angela J. Bahns has shown in her research, people who report on surveys that they personally value diversity are indeed more likely than others to have friendships with a high variety of race, religion, and sexual orientation. At the same time, these subjects were also the most likely to have friend groups that were homogeneous in political attitudes and social values. Apparently, that Celebrate Diversity! bumper sticker generally refers to looking different while thinking the same.

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This is a shame, because diversity of attitudes can be one of the most beneficial kinds. Management researchers have long found that diversity of ideas and ideology leads to better, more creative business outcomes. But new research takes this further, showing that under the right circumstances of respectful, courteous exchange, explicit political disagreement on teams leads to superior performance. In a 2019 article in Nature, scholars at the University of North Carolina at Chapel Hill and the University of Chicago studied the quality of Wikipedia entries on disputable topics that had been written and edited by different groups. They found that in the context of Wikipedia’s strong collaborative and civil norms, the highest-quality entries had been produced by the most politically polarized teams, compared with politically homogeneous teams. This was because individuals were inhibited by their peers from presenting only one side of the issue in question.

Unfortunately, too many forums where conflicting attitudes come into play tend to reward abuse (as is usually the case on social media). Other communities, such as academia, are often so ideologically homogeneous that the necessary balance for beneficial diversity of attitudes to flourish is difficult or impossible to achieve.

Knowing that diversity in your social life is good for your happiness and success is one thing; making it happen is another. Here are three ways to get started:

1. Talk to strangers.
The social path of least resistance is to stay in your traditional friend group, where interactions are familiar and easy. But as the psychologists Nicholas Epley and Juliana Schroeder have demonstrated, this posture is partly based on overestimating how awkward or unpleasant it will be to meet new people. In their experiment, they asked some groups of participants to initiate conversation with strangers on trains and buses, and other groups not to. They found that almost everyone thought beforehand that not talking to strangers would be more pleasant than doing so; their results showed that participants discovered the opposite was true.

You might want to reject this advice out of a sense of politeness, because you feel that trying to get more diversity into your life by interacting with strangers would be an intrusion. This concern is misplaced. In a separate experiment in their study, Epley and Schroeder found that the strangers who’d encountered their subjects had an equally positive experience. And in follow-up experiments, the researchers found confirmation that strangers were almost always interested in talking.

2. Become a social scientist.
Now, onto the harder-to-achieve kind of diversity, in attitudes and viewpoints. Unless you are hoping to free up the seat next to you on a bus, I don’t recommend initiating a conversation with a stranger with your strong opinions about recent Supreme Court decisions. Even if the person happens to agree with your view, you will probably seem unhinged and inappropriate. What works better is modifying your personal environment to make it more inviting for others to give their views without feeling threatened. The best way to do this is to ask people you meet socially for their honest views on issues.

[Arthur C. Brooks: Aristotle’s 10 rules for a good life]

If this seems terribly difficult, it can help to imagine that you are a social scientist doing research: Seek out people with whom you’re likely to disagree, and solicit their views in a friendly way. Your goal should be to understand them deeply—you might offer alternative views, but you don’t want to contaminate your work by seeming combative. This approach will set people at ease, give you more interesting friends, and occasionally even change your mind—or you will change theirs, in part by the model of your curiosity and intelligent listening.

3. Celebrate heresy.
If you want to go all-in, try creating a friend group that explicitly encourages heterodox thinking. Some of the most rewarding social circles I’ve belonged to were those in which everyone thrilled at hearing ideas far outside their comfort zone, politically, philosophically, and morally. The point isn’t to agree at all; it is to have your mind expanded without the threat of canceling or risk of being canceled.

This is the spirit of 19th-century free thinkers, who questioned everything without fear or favor. Perhaps the greatest proponent of this way of thinking was the writer Robert G. Ingersoll, dubbed “the Great Agnostic” for his willingness to question everything. In his 1877 book, Heretics and Heresies, Ingersoll wrote, “Heresy is the eternal dawn, the morning star, the glittering herald of the day. Heresy is the last and best thought. It is the perpetual New World, the unknown sea, toward which the brave all sail. It is the eternal horizon of progress.”

Here is one final way to embrace—in a literal sense—diversity: If you are in the dating pool, try starting a romance with someone very different from you. I’ve previously written about the growing tendency among daters to seek a partner with maximum compatibility in background, personality, and attitudes. Dating apps often facilitate this, making it possible to pair up with, well, yourself. Compatibility can be a way to minimize potential conflict, but not a way to maximize surprise, adventure, and excitement, which are fundamental to romance. That explains researchers’ finding that when prospective daters text each other, a spark of attraction is more likely when people perceive dissimilarity from their own personality.

Perhaps this suggests how the UN should reframe Diversity Day. To get more sorely needed romance and adventure into our world, next May 21 could be reframed as International Date-Your-Opposite Day.