Not too many decades ago it seemed “obvious” both to the general public and to sociologists that modern society has changed people’s natural relations, loosened their responsibilities to kins and neighbors, and substituted in their place superficial relationships with passing acquaintances. However, in recent years a growing body of research has revealed that the “obvious” is not true. It seems that if you are a city resident, you typically know a smaller proportion of your neighbors than you do if you are a resident of a smaller community. But, for the most part, this fact has few significant consequences. It does not necessarily follow that if you know few of your neighbors you will know no one else.

Even in very large cities, people maintain close social ties within small, private social worlds. Indeed, the number and quality of meaningful relationships do not differ between more and less urban people. Small-town residents are more involved with kin than are big-city residents. Yet city dwellers compensate by developing friendships with people who share similar interests and activities. Urbanism may produce a different style of life, but the quality of life does not differ between town and city. Nor are residents of large communities any likelier to display psychological symptoms of stress or alienation, a feeling of not belonging, than are residents of smaller communities. However, city dwellers do worry more about crime, and this leads them to a distrust of strangers.

These findings do not imply that urbanism makes little or no difference. If neighbors are strangers to one another, they are less likely to sweep the sidewalk of an elderly couple living next door or keep an eye out for young troublemakers. Moreover, as Wirth suggested, there may be a link between a community’s population size and its social heterogeneity (多样性). For instance, sociologists have found much evidence that the size of a community is associated with bad behavior including gambling, drugs, etc. Large-city urbanites are also more likely than their small-town counterparts to have a cosmopolitan (见多识广的) outlook, to display less responsibility to traditional kinship roles, to vote for leftist political candidates, and to be tolerant of nontraditional religious groups, unpopular political groups, and so-called undesirables. Everything considered, heterogeneity and unusual behavior seem to be outcomes of large population size.

Suppose you are out shopping and come across an acquaintance who starts telling you a story that seems to be dragging on and on. You want to seem interested, so you offer the occasional “Oh” or “I see”. To your surprise, though, this person angrily stops in their tracks and says, “Sorry if I’m boring you!”

Where did this come from? Clearly, your body language must have betrayed you. The idea that verbal (口头的) and nonverbal messages can conflict was the inspiration for a recently published study from Yale University’s Lueylle Armentano. As part of her study of communication in relationships, Armentano’s research also examined communication channels in people meeting for the first time.

To test the role of verbal-nonverbal mismatch on emotional communication, Armentano and her partner created experimental conditions to see what happens when someone asks for help from strangers. The research team created videotapes of a fellow Yale student expressing nervousness in his words, bodily gestures, or both. The bodily gestures included running his hands through his hair, grabbing his arm, and facially expressing uneasiness. The key question was whether the other participants, another 82 Yale students, would believe the student and provide the help he was requesting. They needed to give their responses.

Turning to the findings, those nonverbal cues (提示) of nervousness had a greater impact on helping behavior than the verbal cues. Surprisingly, helping behavior was the highest when verbal expressions of nervousness were low but nonverbal cues were high.

Recognizing that your body language can outweigh your words means that you need to be mindful of what your body is doing when you’re interacting with others. Generally, when someone is speaking to you, you want to look like you’re interested. Not only should you maintain eye contact, but you should keep your body still and face toward the other person. If you’re not trying to look interested, it may be more polite to say you have to be somewhere else.

Most of us are already aware of the direct effect we have on our friends and family. But we rarely consider that everything we think, feel, do, or say can spread far beyond the people we know. Conversely(相反地), our friends and family serve as conduits(渠道) for us to be influenced by hundreds or even thousands of other people. In a kind of social chain reaction, we can be deeply affected by events we do not witness that happen to people we do not know. As part of a social network, we go beyond ourselves, for good or ill, and become a part of something much larger.

Our connectedness carries with it fundamental implications(影响) for the way we understand the human condition. Social networks have value precisely because they can help us to achieve what we could not achieve on our own. Yet, social­network effects are not always positive. Depression, obesity, financial panic, and violence also spread. Social networks, it turns out, tend to magnify(放大) whatever they are seeded with.

Partly for this reason, social networks are creative. And what these networks create does not belong to any one individual—it is shared by all those in the network. In this way, a social network is like a commonly owned forest: We all stand to benefit from it, but we also must work together to ensure it remains healthy and productive. While social networks are fundamentally and distinctively human, and can be seen everywhere, they should not be taken for granted.

If you are happier or richer or healthier than others, it may have a lot to do with where you happen to be in the network, even if you cannot recognize your own location. And it may have a lot to do with the overall structure of the network, even if you cannot control that structure at all. And in some cases, the process feeds back to the network itself. A person with many friends may become rich and then attract even more friends. This rich­get­richer dynamic means social networks can dramatically reinforce two different kinds of inequality in our society: situational inequality and positional inequality.

Lawmakers have not yet considered the consequences of positional inequality. Still, understanding the way we are connected is an essential step in creating a more just society and in carrying out public policies affecting everything from public health to the economy. We might be better off vaccinating(接种疫苗) centrally located individuals rather than weak individuals. We might be better off helping interconnected groups of people to avoid criminal behaviour rather than preventing or punishing crimes one at a time.

If we want to understand how society works, we need to fill in the missing links between individuals. We need to understand how interconnections and interactions between people give rise to wholly new aspects of human experience that are not present in the individuals themselves. If we do not understand social networks, we cannot hope to fully understand either ourselves or the world we inhabit.