All of these studies, as well as our own Harvard Study, bear witness to the importance of human connections. They show that people who are more connected to family, to friends, and to community, are happier and physically healthier than people who are less well connected. People who are more isolated than they want to be find their health declining sooner than people who feel connected to others. Lonely people also live shorter lives. Sadly, this sense of disconnection from others is growing across the world. About one in four Americans report feeling lonely—more than sixty million people. In China, loneliness among older adults has markedly increased in recent years, and Great Britain has appointed a minister of loneliness to address what has become a major public health challenge.

Throughout this book, we’ll be addressing some of the common reasons why people have a hard time finding happiness and satisfaction in life, but there are a couple of general truths that should be acknowledged right off the bat.

The first is this: the good life may be a central concern for most people, but it is not the central concern of most modern societies. Life today is a haze of competing social, political, and cultural priorities, some of which have very little to do with improving people’s lives. The modern world prioritizes many things ahead of the lived experience of human beings.

The second reason is related and even more fundamental: our brains, the most sophisticated and mysterious system in the known universe, often mislead us in our quest for lasting pleasure and satisfaction. We may be capable of extraordinary feats of intellect and creativity, we may have mapped the human genome and walked on the moon, but when it comes to making decisions about our lives, we humans are often bad at knowing what is good for us. Common sense in this area of life is not so sensible. It’s very difficult to figure out what really matters.

These two things—the haze of culture and the mistakes we make in forecasting what will make us happy—are woven together and play a role in our lives every single day. Over the course of a life, they exert significant influence. The culture we live in leads us in particular directions, sometimes without our even noticing, and we follow along, outwardly pretending that we know what we’re doing, but inwardly in a state of low-grade confusion.

In one fascinating study, researchers divided a set of participants (who wanted a coffee) into two groups: one group was instructed to have an interaction with the barista, and the other to be as efficient as possible. Like the “strangers on a train” study that we mentioned in Chapter Two, the researchers found that people who smiled, made eye contact, and had a social interaction with the barista—in this case, a complete stranger—came away feeling better, and with a greater sense of belonging, than those who were instructed to be as efficient as possible. In short, having a friendly moment with a stranger was uplifting.

Small moments can provide an uplift for our mood and they can help balance out some of the stress we feel. An annoying commute can be softened by a short conversation with the security guard at work. A sense of disconnection can be alleviated when we say hello to our mail carrier. These kinds of minute interactions can affect our mood and energy throughout the day. If we get in the habit of seeking out and noticing opportunities for these daily uplifts, over time they can have far-reaching effects. Not only for us, but for our social networks as a whole; repeated casual contact has been shown to foster the formation of closer friendships. And sometimes even the most casual contact can open us up to whole new realms of experience.

If you want to keep track of our latest efforts, they can be found at the Lifespan Research Foundation (www.Lifespanresearch.org).

The primary challenge of happiness research comes in the application of insight to actual lives, each of which is highly individual and does not fit neatly into any group template. The findings and ideas we’ve presented in this book are based on research, but science can’t know the turmoil or contradictions you feel in your heart. It can’t quantify the stir that you experience when a certain friend calls. It can’t know what keeps you up at night, or what you regret, or how you express your love. Science can’t say whether you’re calling your kids too much or too little, or whether you should reconnect with a particular family member. It can’t say if it would be better for you to have a heart-to-heart over a cup of coffee or play a game of basketball or go for a walk with a friend. Those answers can only come through reflection, and figuring out what works for you. For anything in this book to be useful, you will need to tune in to your unique life experience and make its lessons your own.

But here’s what science can tell you:

Good relationships keep us happier, healthier, and help us live longer.

This is true across the lifespan, and across cultures and contexts, which means it is almost certainly true for you, and for nearly every human being who has ever lived.

A friend once said of my earlier work that I wrote with a signature of “well-founded hope.” The mountains of systematic research, combined with my dedication to drawing insights from the evidence, provided the “well-founded” part. “But the message is always hopeful,” he said. “You demonstrate with evidence that good can become great, that people can build organizations worthy of lasting, that strong values can win in a hypercompetitive world.” Well-founded hope. This study only added to that signature for me. It made me feel even more hopeful and optimistic, not directly about the world at large, but about people. And people, after all, make the world.