The Architecture of Serendipity

This year’s class is graduating in an amazing era of customization and niches, in which new technologies help us to channel ourselves in our preferred directions. For many people, it is both desirable and possible to create something like a Daily Me, or a MyUniversity.com, or a What-Pleases-Me.com.
Many students use Facebook in just this way; they are expanding their horizons, to be sure, but in a way that can lead, paradoxically, to the emergence of groups that are both large and stunningly homogenous. Or consider student organizations. Harvard has a remarkably large assortment of groups, often consisting of like-minded people. Many students (and graduates) are surrounding themselves with people of similar political views, social backgrounds, and career interests.

A good university combats this tendency. It does so not through mandates or requirements, but through making space for serendipity. Indeed, it creates a kind of architecture of serendipity. It ensures that every week, and maybe every day, you will run into things that catch your eye, bring you up short, and maybe even change your life.

Does serendipity really matter? Consider a clue, coming from a small experiment in democracy, conducted by several colleagues and me in Colorado a few years back. About 60 American citizens were brought together and assembled into 10 groups, each consisting of five or six people. Members of each group were asked to deliberate on three of the most controversial issues of the day: Should the United States sign an international treaty to combat global warming? Should states allow same-sex couples to enter into civil unions? Should employers engage in affirmative action?

As the experiment was designed, the groups consisted of predominantly liberal or conservative members—with the liberal groups coming from Boulder, and the conservative groups from Colorado Springs. (Crucially, the groups were not mixed together.) It is widely known that Boulder tends to be liberal and that Colorado Springs tends to be conservative. The groups were screened to ensure that their members conformed to these stereotypes. (For example, if people in Boulder liked Vice President Cheney, they were cordially excused from the experiment.) People were asked to state their opinions anonymously both before and after a period of group discussion, and also to try to reach a public verdict before the final anonymous statement. What was the effect of discussion?

The results were simple. In almost every group, members ended up with more extreme positions after they spoke with one another. Discussion made civil unions more popular among liberals; discussion made civil unions less popular among conservatives. Liberals favored an international treaty to control global warming before discussion; they favored it more strongly after discussion. Conservatives were neutral on that treaty before discussion; they strongly opposed it after discussion. Mildly favorable toward affirmative action before discussion, liberals became strongly favorable toward affirmative action after discussion. Firmly negative about affirmative action before discussion, conservatives became even more negative about affirmative action after discussion.

The experiment had an independent effect: it made both liberal groups and conservative groups significantly more homogeneous, thus squelching diversity. Before members started to talk, many groups displayed a fair bit of internal disagreement. Even in their anonymous statements, group members showed far more consensus after discussion than before. It follows that discussion helped to widen the rift between liberals and conservatives on all three issues.

This is an experiment, of course, but it tells us a lot about the power of niches and self-sorting. Countless students (and others) are exercising their freedom of choice, with the aid of new technologies, to replicate the Colorado experiment. On the Internet and on campus, they sort themselves into groups of like-minded types. People fence in, and fence out, both topics and points of view. In fact, the Internet is producing fascinating variations on the Colorado experiment every day.

No one doubts that freedom of choice is indispensable in a democratic society. The problem is that for individuals and societies alike, its exercise can create echo chambers or information cocoons. By contrast, a great city, or even a great life, is like a great university: It is full of serendipity, surprises, and items that you would never have placed in your Daily Me, your MyTown.com, your MyCurriculum.com, or even your Facebook page.

If you think about your years at Harvard—or your high school years, or your summers—you’ll probably find that some of the best and most life-defining moments came not from your own self-sorting, but from the power of serendipity. Institutions—including educational institutions—can create an architecture of serendipity. They can promote common spaces in which different types of people mingle together. They can promote interactions between people who are different in terms of political convictions, social backgrounds, and even interests. They can combat self-segregation through housing assignments, curriculum, and social nudges of countless different kinds.

In key ways, the architecture of control and the architecture of serendipity are at odds. Some universities, stores, television broadcasters, and government offices promote the echo chamber; others promote serendipity. My suggestion is that for good lives, good universities, and good societies, the power of self-sorting is at best a mixed blessing. However unpleasant and jarring they can be, unchosen, unanticipated encounters play a crucial role; they are indispensable not only to education but also to citizenship itself. Far from wishing them away, we should welcome them.


Cass R. Sunstein ’75 is a professor at the University of Chicago Law School and the author, with Richard Thaler, of “Nudge: Improving Decisions about Health, Wealth, and Happiness.” He will be joining the Harvard Law School faculty in the fall.