It used to be thought that our genes were historically immutable and that it was not possible to imagine a conversation between culture and genetics.

The reason we form networks is because the benefits of a connected life outweigh the costs. It's to our advantage as individuals and a species to assemble ourselves in this fashion.

There are very fundamental reasons we live our lives in social networks, and if we really understood the role they're playing in our society, we would take better care of social networks and find ways to take advantage of their power to improve our society.

Social media and the Internet haven't changed our capacity for social interaction any more than the Internet has changed our ability to be in love or our basic propensity to violence, because those are such fundamental human attributes.

Whether we appreciate it or not, we live out our lives surrounded by an intricate pattern of social connections... We're all embedded in this network; it affects us profoundly and we may be unaware of its existence, of its effect on us.

We and others have done a bunch of work to show that if your real friends online say or do something, it affects you. But if your acquaintances online say or do something, it does not. People on average have about 106 Facebook friends, but only 5 or 6 real friends.