Human beings are greatly influenced by the actual or apparent behavior of others. Consider just a few examples:
1. Federal judges on three-judge panels are much affected by the votes of their colleagues. Democratic appointees, sitting with two Republican appointees, show pretty conservative voting patterns. Republican appointees, sitting with two Democratic appointees, show pretty liberal voting patterns. Clinton appointees turn out to look a lot like Bush appointees on DRR panels. And in some areas of law, the political party of the president who appointed the two other judges on the panel is a better predictor of a judge’s vote than the political party of the president who appointed that very judge (!).
2. Teenage girls who see that other teenagers are having children are far more likely to become pregnant themselves.
3. Ethnic identification is contagious. When relevant people start to identify in ethnic terms — in clothing choices, rituals, attitudes — “ethnification” can spread rapidly throughout a locality or a society.
4. Broadcasters have been found to mimic each other, producing otherwise inexplicable fads in radio and television.
These social nudges are best explained in two ways. First, the behavior of others conveys information about what is true or right or best. Often people lack entirely reliable information, and they base their choices on what others say or do. Second, the behavior of others imposes reputational pressure. If you want to keep people’s good opinion, you might want to do what they do.
The four examples given above reflect both sets of influences. Reputational pressures are probably of special importance for (3). (For more detail, see Nudge.)
Social nudges can easily be enlisted by libertarian paternalists, who seek to alter behavior without imposing mandates of any kind. Having failed in various efforts to reduce littering on its highways, Texas adopted an inventive “Don’t Mess With Texas” program, in which influential people, including Willie Nelson and players for the Dallas Cowboys, sent strong signals about appropriate behavior. The program has had large effects in reducing litter.
Or consider an intriguing recent experiment designed decrease energy use. In San Marcos, California, people were simply informed about whether they were above-average or below-average users of energy. In the following weeks, the above-average users significantly reduced their use of energy.
The less good news is that the below-average users actually increased their energy use. But a small tweak eliminated this effect. When they were given a happy emotikon, signalling social approval, the below-average users stayed well below average.
Of course there is reason to worry about government efforts in this vein. We could imagine programs that would violate neutrality requirements; consider efforts to promote certain religious practices or political convictions. And here as elsewhere, hard-line libertarians might just want government to stay out. But when government has a legitimate end, and wants to avoid a mandate, social nudges can serve as an immensely effective tool.