Most people spend part of their day going to work, going to a park or a coffee shop, going to the grocery store, or being surrounded by strangers.

However, most of us isolate ourselves because relationships with strangers are uncomfortable for both of us. This belief could be wrong. Our research shows that we often underestimate the positive impact of our relationships with others on our well-being and that of others. For example, chatting with a stranger on the way to work can make both of you happier than you think.

We asked Chicago's bus and train passengers how to communicate while commuting, not sitting alone, or doing their regular work. Many people thought that talking does not like to travel.

However, in actual experiments, people who were randomly assigned to chat were the most comfortable driving. Our passengers believe that only 40% of train passengers are willing to talk to them. However, all participants in our experiment who tried to talk to strangers found that the person sitting next to them liked to talk. If you're not interested in what others have to say or think they don't like you, it can prevent you from connecting.

Research shows that we consistently underestimate how much we like a new person after our first conversation.

The inner life of Strangers

Separate experiments on buses and taxis showed similar results. People surprisingly enjoyed interacting with strangers.

The positive effect seems to affect the interlocutor as well. In another experiment carried out in the waiting room, we found that not only the people who were invited to the conversation but also the people who had to talk to them felt positive emotions.

Of course, no one appreciates unwanted attention. But just saying hello to someone can get you a better response than people think. Few people strike up conversations with strangers, but if you speak with good intentions, most people seem willing to chat. Part of the reason is that the experience of talking to other people and hearing the voices of strangers makes us realize that they have an inner world of thoughts, feelings, emotions, and experiences just as rich as we do.

Such short interactions with strangers will not turn a sad life into a happy one. But you can turn negative moments like the daily commute into positive ones.

Humans are social animals by nature and are happiest and healthiest when connected with others. On the contrary, feeling isolated and alone is a stressor that leads to health risks similar to smoking and obesity.

Having positive social relationships is a key factor in happiness that is far more important than how much we earn.

Cross the dividing line

Professor Epley's team recreated the Chicago experience for the BBC, involving around 700 train passengers on the route from Greater Anglia to London.

Initiatives include:

• Virgin Trains brand all West Coast C buses as 'chat coaches'.
• Arriva is distributing 'Conversation Starter' cards across the national bus network and encouraging passengers to 'share the laugh'.

We invite people from all backgrounds to join Translink Northern Ireland's glider service connecting East and West Belfast.

Self-fulfilling expectations

You might think that only extroverts will benefit the most from interacting with others. Several experiments have shown that both extroverts and introverts are happier when asked to act more extroverted.

I've found that passengers are happier when they talk to strangers, no matter how extroverted they feel. Personality may not significantly influence your experience of connecting with others, but introverts can influence expectations by underestimating the positive effects of interactions.

Your personality can shape your expectations more than your experiences. Our expectations can be fulfilled by themselves. If you feel uncomfortable talking to a stranger, you won't try and you'll never notice that your expectations may be wrong. It can falsely isolate us and separate us from others.

This may help explain why cities are full of highly sociable people who try to ignore each other. Strangers sit side by side on park benches, staring at their phones, and walk the city streets without smiling or saying hello.