FOR most of Western history, truth and morality came from God and king, and free will was a theological question. This began to change in the 1700s, and the idea that humans were individuals with the freedom of rational choice soon wormed its way into the belief systems of the upper echelons of society. Over time, the concepts of rationality and individualism profoundly shaped the governments and culture of the West.
But to what extent are we freethinking individuals? The question matters because economics and much of cognitive science have, at their basis, the concept of an independent individual. Perhaps it is this assumption which has led to the difficulty these disciplines have had accounting for phenomena such as financial bubbles, political movements, mass panics and technology fads.
Recent research is beginning to uncover the degree to which we act as independent individuals. By combining big data from cellphones, credit cards, social media and other sources, we can now observe humans in the same way that biologists can observe animals in their natural habitats using cameras or sonar. From these observations of people, we can derive mathematical rules of behaviour – a “social physics” that provides a reliable understanding of how information and ideas flow from person to person. This social physics shows us how the flow of ideas shapes the culture, productivity and creative output of companies, cities and societies.
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To develop this new science, my students and I have been studying living laboratories. By to all the residents of several small communities, we could track their social interactions with their peers – both friends and acquaintances – and at the same time ask questions about their health, politics and spending behaviour. For instance, when we looked at weight gain, we found that people picked up new habits from exposure to the habits of peers, and not just through interactions with friends. This means that when everyone else in the office takes a doughnut, you probably will too. In fact, this type of exposure turned out to be more important than all the other factors combined, highlighting the overarching importance of automatic social learning in shaping our lives. We found that this same pattern held true for voting and consumer consumption.
The largest single factor driving adoption of new behaviours was the behaviour of peers. Put another way, the effects of this implicit social learning were roughly the same size as the influence of your genes on your behaviour, or your IQ on your academic performance.
The logic behind this is straightforward. If somebody else has invested the effort to learn some useful behaviour, then it is easier to copy them than to learn it from scratch by yourself. If you have to use a new computer system, why read the manual if you can watch someone else who has already learned to use the system? People overwhelmingly rely on social learning and are more efficient because of it. Experiments such as those from my research group show us that, over time, we develop a shared set of habits for how to act and respond in many different situations, and these largely automatic habits of action account for the vast majority of our daily behaviour.
In light of this, perhaps we should ask how important individual choices are compared with shared habits. Here again the power of sharing ideas, as opposed to individual thinking, is clear. When we study decision-making in small groups, we find that the pattern of communication – who talked to whom and how much they talked – is far more important than the characteristics of the individuals. In ranging from call centres to drug-discovery groups, communication patterns are usually the single most important factor in both productivity and creative output. And in in the US and Europe, variations in the pattern of communication accounted for almost all of the differences in average earnings – much more important than variations in education or class structure. Importantly, income per person grows exponentially larger as more people share ideas, so it is the sharing that causes the growth, not just having more individuals contributing.
“How important are individual choices compared with shared habits?”
Instead of individual rationality, our society appears to be governed by a collective intelligence that comes from the surrounding flow of ideas and examples; we learn from others in our environment, and they learn from us. A community with members who actively engage with each other creates a group with shared, integrated habits and beliefs. What social physics shows is that, when the flow of ideas incorporates a constant stream of outside ideas as well, the individuals in the community make better decisions than they could by reasoning things out on their own.
This idea of a collective intelligence that develops within communities is an old one. Indeed, it is embedded in the English language. Consider the word “kith” – familiar to modern English speakers from the phrase “kith and kin”. Derived from old English and old German words for knowledge, kith refers to a more-or-less cohesive group with common beliefs and customs. These are also the roots for “couth”, which means possessing a high degree of sophistication, though its opposite, “uncouth”, may be more familiar. Thus, our kith is the circle of peers – not just friends – from whom we learn the “correct” habits of action.
Our culture and the habits of our society are social contracts, and both depend primarily upon social learning. As a result, most of our public beliefs and habits are learned by observing the attitudes, actions and outcomes of peers, rather than by logic or argument. Learning and reinforcing this social contract is what enables a group of people to coordinate their actions effectively.
Social fabric
It is time that we dropped the fiction of individuals as the unit of rationality, and recognised that our rationality is largely determined by the surrounding social fabric. Instead of being actors in markets, we are collaborators in determining the public good. Indeed, our research has demonstrated that people are much more influenced by their social networks than by individual incentives. For instance, in one we compared the strategy of giving participants cash when they improved their behaviour to the strategy of giving cash to the participants’ buddies. We found giving buddies the reward was more than four times as effective as giving rewards directly to the participants. Similar social network incentives have yielded even more dramatic results when used to encourage energy savings and voting.
This power of the social fabric on individual decision-making is, in fact, the real reason that privacy is so important. As Stanley Milgram’s work on social conformity demonstrated many years ago, the power of social influence can lead people to both good and terrible behaviours, and can transform our behaviour to an extent that is scarcely believable.
Without privacy, the power of corporations or government to manipulate our behaviour becomes virtually unlimited. The answer to the privacy problem is to use – the sort of computer interfaces that banks use to securely transfer money without revealing unnecessary information. Such networks allow you to control information that is about you and consequently limit the ability of others to manipulate you. But that is another story.
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is director of MIT Media Lab’s human dynamics group. He focuses on harnessing information flows, the big-data revolution and incentives within social networks. The studies outlined in this essay are featured in his new book, (Penguin Press)
This article appeared in print under the headline “The death of individuality”
