Does the effect of having a friend become happy tend to wear off? In our study, we found that a person is 45 percent more likely to be happy if a friend became happy in the previous six months. In contrast, the effect is only 35 percent for friends who became happy within the previous year, and it disappears after longer periods of time. So, our friends’ happiness does have an effect on us, but it only lasts for about a year. Just as lottery winners get used to their newfound wealth, we get used to our friends being happy. But if different friends get happy at different points in time, they might give us a periodic boost, helping us to stay above our natural level of happiness.
Alone in the Crowd
If happiness can spread, at least for a while, what about other emotions? One feeling that directly concerns our social network is loneliness. In some sense, loneliness is the opposite of connection—it is the feeling of being disconnected. Work by psychologist John Cacioppo has shown that loneliness is a complex set of feelings experienced by people whose core needs for intimacy and social connection are not met.32 This often motivates most (but not all) people to redress their situation, suggesting that the function of loneliness is to promote reconnection (we will discuss the evolutionary purpose of loneliness in chapter 7).
Psychologists have identified the way that feelings of loneliness fit in with a broad set of other feelings and states, including self-esteem, anxiety, anger, sadness, optimism, and shyness. Psychological research suggests that feelings of loneliness occur when there is a discrepancy between our desire for connection to others and the actual connections we have. This research has focused on the subjective perception of being alone, but feeling lonely is not the same thing. While studies have shown, unsurprisingly, that having a good friend can decrease loneliness, what has not previously been examined is the effect of the whole social network on our tendency to feel lonely even in a crowd.
Using the same network in which we studied happiness, we examined whether being alone was associated with feeling lonely and whether such feelings could spread.33 We found that real-world social connections do have an effect on how we feel. People with more friends are less likely to experience loneliness. Each extra friend reduces by about two days the number of days we feel lonely each year. Since on average (in our data) people feel lonely forty-eight days per year, having a couple of extra friends makes you about 10 percent less lonely than other people. Interestingly, the number of family members has no effect at all. It is not clear why this is the case. Possibly, people in small families know they have a greater responsibility to spend time with one another since there are fewer people to take turns visiting. Or perhaps people in large families primarily feel close to a smaller core of their family, limiting the influence of additional connections. Regardless of the mechanism, it is clear that feelings of loneliness are much more closely tied to our networks of optional social connections than to those handed to us at birth.
Loneliness can actually shape the social network. People who feel lonely all the time will lose about 8 percent of their friends, on average, over two to four years. Lonely people tend to attract fewer friends, but they also tend to name fewer people as friends as well. What this means is that loneliness is both a cause and a consequence of becoming disconnected. Emotions and networks can reinforce each other and create a rich-get-richer cycle that rewards those with the most friends. People with few friends are more likely to become lonely, and this feeling then makes it less likely that they will attract or try to form new social ties.
Our study suggests that physical proximity matters as much for loneliness as it does for happiness. Friends and family who live nearby see each other more often, which should help decrease the likelihood that they feel lonely, but it also makes them more susceptible to one another’s feelings. For example, if a nearby friend has ten extra lonely days a year, it will increase the number of lonely days you experience by about three. If this person is a close friend, then the effect is stronger, and you’ll experience four extra days of loneliness. Loneliness also spreads between next-door neighbors, with ten extra days of loneliness leading to two extra days for the person on the other side of the fence. But neighbors and friends who live more than a mile away do not make each other lonely.
Spouses who live together can affect each other too, but the result is less dramatic. For every ten extra days a person is lonely, his or her spouse will be lonely for just one extra day. And siblings do not appear to affect one another at all (even the ones who live nearby); this provides additional evidence that loneliness is about our relationships to people with whom we choose to connect rather than the relationships we have inherited.
Looking beyond these direct connections, we found that loneliness spreads three degrees, just like happiness. A person’s loneliness depends not only on his friends’ loneliness, but also on his friends’ friends’ and his friends’ friends’ friends’ loneliness. The full network shows that you are about 52 percent more likely to be lonely if a person you are directly connected to (at one degree of separation) is lonely. The effect for people at two degrees of separation is 25 percent, and for people at three degrees of separation, it is about 15 percent. At four degrees of separation the effect disappears, in keeping with the Three Degrees of Influence Rule.
Finally, we observed an extraordinary pattern at the edge of the social network. At the periphery, people have fewer friends; this makes them lonely, but this also tends to drive them to cut the few ties that they have left. But before they do, they may infect their friends with the same feeling of loneliness, starting the cycle anew. These reinforcing effects mean that our social fabric can fray at the edges, like a strand of yarn that comes loose from the sleeve of a sweater. If we are concerned about combating the feeling of loneliness in our society, we should aggressively target the people at the periphery with interventions to repair their social networks. By helping them, we can create a protective barrier against loneliness that will keep the whole network from unraveling.
Feeling in Love
The psychology of emotions such as happiness and loneliness sheds light on the formation and dissolution of ties in social networks. In fact, human sensibilities such as anger, sadness, grief, and love all operate in the service of social ties. One can be angry at nature or saddened by a forest fire or love a pet, but these emotions have their origin and find their fullest expression in the anger, sadness, or love one feels in the setting of interpersonal relationships.
People the world over have different ideas, beliefs, and opinions—different thoughts—but they have very similar, if not identical, feelings. And they have similar responses to feelings in others, preferring happy friends to depressed ones, kind friends to mean ones, and loving friends to violent ones. A whole range of emotions can spread, from anger and hatred to anxiety and fear to happiness and loneliness. But there is one emotion central to human experience that we have not yet considered and that is key to understanding social connection: love.
The psychology of love and affection is obviously crucial to an understanding of the formation of social ties between people. As anthropologist Helen Fisher has argued, the sensibility of being in love may be broken down into lust, love, and attachment, all of which likely served evolutionary purposes.34 The feeling of lust has the obvious goal of driving reproduction—with almost any partner. The feeling of romantic love is something different, of course, and tends to be focused on a particular partner, or at least one partner at a time. From an evolutionary perspective, this allows the individual to conserve precious resources and not waste them in the pursuit of several objects of affection. The feeling of attachment, and the secure tie to another person that it represents, may have evolved to allow parents to jointly care for their young, which also has evolutionary advantages.
In chapter
