For security purposes, information is shared using an "answer architecture" that makes yes-or-no queries of the open personal data store (openPDS) on a user's smartphone, Pentland says, much like the SWIFT platform banks use to exchange information. In this manner, and in accordance with the U.S. Consumer Privacy Bill of Rights and the European Union Directive on Privacy and Electronic Communications, the data belongs to the individual.
Societal patterns and habits inherent in these data sets can predict behavior, such as the likelihood of residents of a certain neighborhood developing diabetes or alcoholism. (Predicting behavior from verbal and visual cues, it turns out, is rather easy; technology that Pentland and his team have developed is used by two large health insurers to screen callers for signs of depression.)
However, if exposure to external forces drives behavior changes, Pentland says, then getting to the root of the problem means changing exposure. Through its research, Pentland's lab reports that social influence -- knowing that others are being rewarded for good behavior, such as riding a bicycle to the office -- is more than three times as effective as simply receiving that reward on an individual basis.
This influence has helped veterans coping with post-traumatic stress disorder, who see that fellow veterans are more active and social and decide to do something about it, but further uses within the highly individualized U.S. health care system are only emerging slowly.
2. Social networking: For best results, group like-minded people
An obvious source of social influence, of course, is social networking, the rapid rise of which has demonstrated the ability of anonymous peer-to-peer interaction to influence behavior. This occurs because social networks forge what Damon Centola, assistant professor of behavior and policy science at MIT, calls "weak ties" that, despite their moniker, actually increase the diffusion rate of behaviors and ideas. You may not have had a friend living in the Middle East during the Arab Spring, for example, but you likely had a friend of a friend. Put another way, it's a small world after all.
Centola says that changing behaviors as a result of social network influence doesn't work so simply, though. The reason is the difference between what are called simple and complex contagions. It only takes a single contact to tell you that smoking is bad for you (simple contagion), but it will take multiple contacts to get you to quit smoking (complex contagion), Centola says. Information can spread among the weak ties of a randomized network, but when it comes to behavior change, it's only a matter of time before there are no longer any ties that bind.
The answer, Centola found by leveraging the infrastructure of MIT's online fitness program, is to connect users to "neighbors" based on the concept of homophily, meaning "love of the same."