How often do you chat with the strangers you encounter during the course of your day? The answer should be: Often. Fascinating research shows that even a few moments of conversation with the person who takes your coffee order or the stranger seated next to you during your commute creates a measurable improvement in mood. But research also showed that most of us are reluctant to start these conversations because we expect the opposite.

A few years ago, psychologists at the University of British Columbia in Vancouver began wondering whether our search for efficiency was harming our collective mood by limiting the time we're willing to spend interacting with strangers. To find out, they sent test subjects into a busy Starbucks, instructing them to either get in and out as quickly as possible, or to spend a few moments conversing with the cashier. Those who chatted wound up in a better mood, and they had a stronger sense of belonging to their community.

In a similar experiment, University of Chicago researchers Nicholas Epley and Juliana Schroeder found that commuter train and bus passengers who talked to nearby strangers found their commute more enjoyable than those who didn't. But intriguingly, in that experiment, subjects were asked to predict whether they'd enjoy the commute more if they chatted with other people or stayed silent and most expected the more solitary experience to be more pleasurable.

We stay silent because we assume others don't want to talk to us.

Why do people--wrongly--expect to have a worse experience if they talk to those around them than if they don't? Social anxiety appears to be the problem. In follow-up experiments, Epley and Schroeder determined that people's reluctance to start conversations with nearby strangers comes partly from "underestimating others' interest in connecting." The sad thing is that people who assume that a nearby stranger doesn't want to converse--and thus don't start a conversation--never get to find out whether the person next to them actually wanted to chat or not. Only those who forced themselves to chat because it was required by the experiment found out what a pleasant experience it could be.

In other words, most of us could be happier if we just took a little time to chat with the strangers we encounter every day--only we don't because we're afraid they won't want to talk to us. "Human beings are social animals," Epley and Schroeder write. "Those who misunderstand the consequences of social interactions may not, in at least some contexts, be social enough for their own well-being."

There's a clear message here: You should be chatting with the strangers you encounter. Or if you're too shy for that, making eye contact will have some of the same effect, especially if you also smile, further research found. You may occasionally happen on a curmudgeon who brushes you off and makes you feel small--and that encounter might stick in your memory because the human brain is biased to dwell on negative rather than positive events. But starting conversations with strangers is still well worth the risk of rejection.

If it surprises you to learn that chatting with strangers will make you happier, it might surprise you even more to know that it will likely make them happier too. "The pleasure of connection seems contagious," Epley and Schroeder write. "In a laboratory waiting room, participants who were talked to had equally positive experiences as those instructed to talk." 

In other words, pushing past your reluctance to initiate conversations with strangers won't only make you happier. It will make them happier too.