WSJ: Our Social Networks, Ourselves

http://online.wsj.com/article/SB10001424052748703521304576279043290578796.html

APRIL 23, 2011

Our Social Networks, Ourselves

Does free will even exist? Scientists are finding that we're much more predictable than we think

By JONAH LEHRER

(See Correction & Amplification below.)

In recent decades, scientists studying the human brain have steadily eroded traditional notions of free will and autonomy. It turns out that our choices are often circumscribed by mental circuits beyond our control and outside of conscious awareness.

But now, thanks to new forms of data, such as cellphone information, and powerful analytical tools, scientists can see the forces that shape our lives from the outside. They can discover striking correlations and document all of the different ways that the world around us--from our social networks to the neighborhoods in which we live--influences everything we do.

Consider a few of these correlations:

Physicists at the Sante Fe Institute have found that when people move to a city that's twice as large as where they had been living, they earn, on average, 15% more money and invent 15% more patents. They also walk down the sidewalk 15% faster.

Nicholas Christakis of Harvard and James Fowler of the University of California, San Diego, have repeatedly shown that our social networks--those family members, friends and acquaintances we regularly interact with--strongly influence our health. According to the data, if a person becomes obese, the likelihood that one of his or her friends will become obese increases by 57%. If someone becomes obese, the chance that a sibling will also become obese increases by 40%. In fact, even the friends of our friends seem to have an effect on our body weight.

Moods are also contagious. When a person is happy, nearby friends are 25% more likely to also be happy, according to research from Harvard Medical School. These viral emotions can even spread via online networks, such as Facebook and Twitter.

A study by sociologist Martin Ruef of Princeton found that entrepreneurs with a diverse circle of contacts--they interacted with many people outside their field--were three times more innovative than those with a more predictable group of friends.

The Stanford sociologist Mark Granovetter has shown that our weak tie relationships--those casual interactions with people we rarely see--are often the most important factor when it comes to getting a job. As a result, people with more weak ties typically spend less time searching for employment and end up with higher-quality jobs. As the saying goes, success is largely about who you know.

Such studies are a reminder that John Donne was right: No man is an island. Although we can't help but believe in our autonomy--free will is a fiction we need--this latest research suggests we're not nearly as free as we typically assume.

That's why, for instance, researchers can make accurate predictions about our eating habits, academic interests and political beliefs based on the trail of data secreted by our smartphones. It's also why companies such as Amazon and Netflix can develop shopping algorithms that know exactly what we want, even though they know nothing about us. The data generated by the group can be used to decipher the individual.

There is, of course, something unsettling about this new field of study. We don't want to think of our gadgets as a window into the soul, or to worry about how our neighbors are influencing what we eat for dinner, or to believe that our movie preferences can be summarized by an equation.

And yet, this research is ultimately a sign that we depend upon each other, that our lives are deeply intertwined. That might make us a bit more predictable--we are always learning from our friends--but it's also something we desperately need. The same studies that document the power of the social network have also shown that, when people are cut off from the network, they lead much shorter lives. These individuals might be more autonomous, but they are also lonely. And loneliness is terrible for our minds and bodies.

--Mr. Lehrer is the author of "How We Decide" and "Proust Was a Neuroscientist."

Correction & Amplification

A previous version of this essay contained a garbled sentence. The passage should read: A study by sociologist Martin Ruef of Princeton found that entrepreneurs with a diverse circle of contacts--they interacted with many people outside their field--were three times more innovative than those with a more predictable group of friends.