There's a fundamental paradox right at the core of human life. On the one hand, decades of research have shown that we are highly social creatures who are made happier and healthier by reaching out and connecting with other people. And yet, on the other hand, every day there are opportunities, big and small, to reach out and connect with other people that we choose not to take. We avoid talking to strangers. We lean back and type to each other rather than leaning in and talking to each other. If being socially connected is so darn good for us, then why do we so often seem to be so darn unsocial?

This paradox hit me like a freight train one morning while I was on an actual train, commuting into my office at the University of Chicago. Everybody was in a desperate search for their own little acreage of solitude right along the window. We chose to ignore each other. A woman sat down next to me wearing a fabulous, killer, stylish red hat. I decided to put myself in an experiment. Instead of keeping to myself and doomscrolling, I'd try to have a conversation with her. The second I had that thought, my brain started screaming at me all the reasons why this was a really, really bad idea. "Clearly, she doesn't want to talk to you... She's going to think you're some kind of creep." Nevertheless, I decided the experiment must continue. I turned to her and I said, "Hi, my name is Nick. I love your hat." She turned to me, a big smile, her face all lit up. The conversation just flowed really easily. 30-minute train ride just went like that. The contrast between my beliefs about how that would go and how it actually went was pretty sizable. And there, in that gap, was a potential resolution to this paradox. Social connection, after all, isn't something that just happens to us. It's a choice we make.

In my career, my wonderful collaborators and I have now conducted well over 100 experiments with over 30,000 people and found that my tendency to be overly pessimistic is not unique to me. In one of our very first experiments, we asked commuters to predict how they would feel if they kept to themselves or if they tried to connect. People thought talking to a stranger was a really bad idea. But when we actually randomly assigned them to either keep to themselves or to try to connect, we found exactly the opposite results. People’s beliefs about social interaction here weren’t just wrong -- they were precisely backward. But notice that if you believe that talking with a stranger would suck, you wouldn't try it, and then you'd never find out that you might be wrong about that. Pessimistic beliefs in that way are self-fulfilling.

We've now seen this tendency to be overly pessimistic over and over again. We’ve had more than 4,500 people have deep conversations with a stranger. When I show people these questions, I can feel a sense of dread spreading over the room. But when I actually put them into the experiments, the trouble I have is getting them to come back. These conversations go much better than people expect that they will. We find in our research that we have tremendous power to create meaningful social connection every day of our lives. But if we underestimate how positively our efforts to reach out and connect with someone will go, we won't use that power that we have.

No research I've ever been involved with has changed the way I live my life more than this. My train rides are almost never silent anymore. I met amazing people on planes and in cabs. Even just walking around town is more pleasant for me because I’ve made a habit of walking around with my head up smiling and saying hello to other people. When I feel grateful, I write a note and send it off. When I need help, I’m less reluctant to ask for it. It's made me a more open, friendlier person and as a result, changed all of my relationships.

These changes didn't happen to me overnight. They happened, of course, slowly, over time. Just like you move a mountain -- not by pushing it all at once, but one shovelful at a time. The way you change how you approach other people happens slowly, over time. One choice after another. One small choice, as you learn where your mistaken beliefs about other people might be holding you back needlessly. And then you develop habits that then become part of your character and part of who you are.

Overcoming my misplaced pessimism also affected how I've made some big choices, including when pain struck my family. 10 years ago, my wife Jen and I learned that our daughter, Sophie, had Down syndrome, and three months after that, we learned that our daughter had died before she could be born. Losing our daughter was absolutely horrible. Until one morning Jen asked whether we might consider adopting a child with Down syndrome. And there it was, the choice. Do you reach out and connect?

I had all the pessimistic fears multiplied by 100 or 1,000. My first thought was, I don't think we can do this. But my second thought then started turning to my data. I started thinking about thousands and thousands of data points of people underestimating the joys they would experience when they reach out to engage with someone. And it gave me data-driven courage. Jen and I boarded a flight to China to meet Lindsey, two years old, with big dark eyes and a relentless smile. Connecting with Lindsey has enriched and blessed our lives so far beyond what my pessimistic expectations beforehand ever possibly could have imagined.

Connecting with other people is one of the most consistently enjoyable experiences we'll ever have. And yet, our choice is thwarted by overly pessimistic fears. Being overly pessimistic doesn't mean we should reach out all the time; it means we tend to hold ourselves back a little too often. You want to change your life for the better? I suggest keeping some data-driven courage in mind. And when in doubt, reach out.