Balancing group and self-interest has never been easy, yet human societies display a high level of cooperation. To attain that level, specialized traits had to evolve, including such emotions as shame.1 Shame is what is supposed to occur after an individual fails to cooperate with the group. Shame regulates social behavior and serves as a forewarning of punishment: conform or suffer the consequences. The earliest feelings of shame were likely over issues of waste management, greediness, and incompetence. Whereas guilt is evoked by an individual's standards, shame is the result of group standards. Therefore, shame, unlike guilt, is felt only in the context of other people.

The first hominids could keep track of cooperation and defection only by firsthand observation. Many animals use visual observations to decide whether to work with others. Reef fish in the Red Sea, for instance, watch wrasses clean other reef fish to determine whether or not they're cooperative, as the biologist Redouan Bshary discovered. Bshary went scuba diving off Egypt's coast to observe this symbiotic relationship. Bluestreak Cleaner wrasses (Labroides dimidiatus) eat parasites, along with dead or infected tissue, off reef fish in more than two thousand interactions a day, each of which can be considered an act of cooperation. Wrasses are tempted to eat more than just the parasites, but if the reef fish loses too much flesh in the deal, it will refuse to continue working with the wrasse. Reef fish approach wrasses that they see cooperating with their current clients and avoid the wrasses they see biting off more than they should.2

Like the Bluestreak Cleaner wrasses, humans are more cooperative when they sense they're being watched. Researchers at the University of Newcastle upon Tyne examined the effect of a pair of eyes on payments for tea and coffee to an honesty box. Alternating images of flowers and human faces were posted above the box in the university coffee room each week for ten weeks; researchers found that people paid nearly three times as much for their drinks in weeks during which they were exposed to the human gaze.3

The feeling of being watched enhances cooperation, and so does the ability to watch others. To try to know what others are doing is a fundamental part of being human. So is fitting in. The more collectivist the human society, the more important it is to conform and the more prominent the role of shame.4 Shame serves as a warning to adhere to group standards or be prepared for peer punishment. Many individualistic societies, however, have migrated away from peer punishment toward a third-party penal system, such as a hired police force, formal contracts, or trial by jury. Shame has become less relevant in societies where taking the law into one's own hands is viewed as a breach of civility.

Perhaps this is why it makes us uncomfortable to contemplate shaming people: shame invites the public in on the punishment. Consider the stocks, scab lists during union strikes, or Nathaniel Hawthorne's The Scarlet Letter. Or the proposal made by the prominent conservative William F. Buckley, Jr., in 1986 to tattoo people with AIDS. These instances of shaming now seem an affront to individual liberty. Getting rid of shaming seems like a pretty good thing, especially in regulating individual behavior that does no harm to others. In eschewing public shaming, society has begun to rely more heavily on individual feelings of guilt to enhance cooperation.

Guilt prevails in many social dilemmas, including one area of my own research: overfishing. At the root of the problem of overfishing is the human appetite. Wild-fish catches are declining, and many of us seek to avoid the guilt brought on by eating unsustainable seafood. Here are just a few recent headlines from major newspapers: "HOLY MACKEREL AND OTHER GUILT-FREE FISH" (The New York Times), "GUILT-FREE SUSHI" (The Christian Science Monitor), "COD AND CHIPS? MAKE IT POLLOCK IN GUILTFREE GUIDE TO SEAFOOD" (The Times of London), and "A GOOD APPETITE; SEAFOOD, EASY AND GUILT-FREE" (The New York Times).

It is perhaps unsurprising that a set of tools has emerged to assuage this guilt and, in the case of seafood, reform the appetite.5 These tools aim to divert demand from one type of seafood toward another. Wallet cards, iPhone apps, and ecolabels tell consumers which fish ought to be and ought not to be eaten. Shoppers in Europe have been given rulers so that they can measure fish and avoid buying juveniles.

Guilt abounds in many situations where conservation is an issue. Harried by guilt, one mother reuses her daughter's bathwater for her own bath. Los Angeles shoppers refuse to buy blueberries imported from Chile because of the fuel consumed in shipping them. Another woman feels guilty about the natural habitat lost to cocoa cultivation and refuses to buy chocolate, prompting her husband to say that she took the joy out of his Almond Joy.6 Just as the devout purchased guilt-alleviating papal indulgences in the Middle Ages, guilt-ridden consumers today buy carbon offsets, LED lightbulbs, and hybrid cars and can be guided to something approaching sanctity by books such as The Virtuous Consumer, The Rough Guide to Shopping with a Conscience, and The Eco Chick Guide to Life: How to Be Fabulously Green.

The problem is that environmental guilt, though it may well lead to conspicuous ecoproducts, does not seem to elicit conspicuous results. One supermarket chain introduced signs at the fish counter to show the most and least sustainable seafood: sales of the green-tagged "best choice" fish increased an average of 29 percent per week, sales of yellow-tagged "proceed with caution" seafood declined an average of 27 percent per week, but the sales of the red-tagged "worst choice" seafood—i.e., the heavily overfished species—remained the same.7 Between 1980 and 2008, sales of pesticides increased by 36 percent in the state of California, the birthing ground of the organic food ecolabel.8 Despite sporadic instances of such measures as carpooling and the use of cloth grocery bags in lieu of plastic, the demand for oil in the United States has grown by 30 percent overall and 5 percent per capita since 1990.9 The positive effect of idealistic consumers does exist, but it is masked by the rising demand and numbers of other consumers.

Guilt is a valuable emotion, but it is felt by individuals and therefore motivates only individuals. Another drawback is that guilt is triggered by an existing value within an individual. If the value does not exist, there is no guilt and hence no action (e.g., the sales of red-tagged "worst choice" seafood remained the same). What if the aim were to promote a value felt by the group but not necessarily by every individual in the group? Many problems, like most concerning the environment, are group problems. Perhaps to solve these problems we need a group emotion. Maybe we need shame.

Shaming, as noted, is unwelcome in regulating personal conduct that doesn't harm others. But what about shaming conduct that does harm others? The U.S. National Sex Offender Registry provides an online database with the names, photographs, and addresses of sex offenders in every state. In March 2010, Nebraska lawmakers approved a bill that allows the state to publish online the names and addresses of people owing more than $20,000 in taxes. Judges in various states issue shaming punishments, such as sentencing pickpockets and robbers to carry picket signs that announce their crimes to the public. These instances of shaming might deter bad behavior, but critics such as Martha Nussbaum, a political philosopher at the University of Chicago, argue that shaming by the state conflicts with the law's obligation to protect citizens from insults to their dignity.10

What if government is not involved in the shaming? A neighborhood in Leicester, England, has a YouTube channel dedicated to neighborhood issues, including catching "litter louts." A collection of videos shows individuals caught in various acts of littering, and if someone recognizes the litter lout, he or she can e-mail the lout's identity to the neighborhood management board, which passes it on to the City Council so that fines can be issued and the video removed.11 In 2008, The Santa Fe Reporter published the names and addresses of the top ten water using households in the city (first place went to a home owner who used twenty-one times the household average). The tennis club near my apartment in Vancouver, British Columbia, publishes the names of people who don't pay their dues. In each of these cases, the activity of the individual compromises the community. In none of them is the state involved in the shaming. Is this a fair use of shaming? Is it effective?

Let's deal with the latter question. Shaming might work to change behavior in these cases, but in a world of urgent, large-scale problems, changing individual behavior is insignificant. Small changes, adopted by one individual at a time, can make a difference in a problem only when the problem is small or there is lots of time to solve it (for instance, in marginalizing politically incorrect words). Many of today's social movements, like the industries they seek to revolutionize, must make big changes quickly—which is best accomplished by directing efforts upward toward institutions. I call this vertical agitation. The Santa Fe Reporter listed the top ten commercial water users, in addition to the top ten households. The first of these offenders, the city of Santa Fe, used 195 times as much water as the number one household offender. Imagine the relative difference in getting the city to commit to water-saving techniques as compared to reforming a single household.

Guilt cannot work at the institutional level, since it is evoked by individual scruples, which vary widely. But shame is not evoked by scruples alone; since it's a public sentiment, it also affects reputation, which is important to an institution. At the 2004 meeting of the World Economic Forum in Davos, Switzerland, leading CEOs issued a press release showing that corporate brand reputation outranked financial performance as the most important measure of success. For an example of how shame and reputation interact, consider restaurant hygiene cards, introduced in 1998 by Los Angeles County as a shaming technique in the interests of public health. Restaurants were required to display grade cards that corresponded to their most recent government hygiene inspection. The large grade in the window—A, B, or C—honors restaurants that value cleanliness most and shames those that value it least. The grade cards have apparently led to increased customer sensitivity to restaurant hygiene, a 20 percent decrease in countywide hospitalizations for food-borne illnesses, and better hygiene scores for county restaurants.12

Recall that in our early evolution we could gauge cooperation only firsthand. As group size got bigger and ancient humans grappled with issues of necessary cooperation, the human brain became better able to keep track of all the rules and all the people. The need to accommodate the increasing number of social connections and monitor one another could be, according to the social grooming hypothesis put forward by the British anthropologist Robin Dunbar, why we learned to speak.13 Then, five thousand years ago, there arose another tool: writing. Language, both oral and written, allowed for gossip, a vector of social information. Research carried out by Ralf Sommerfeld of the Max Planck Institute for Evolutionary Biology and his colleagues demonstrated that in cooperation games that allowed players to gossip about one another's performance, positive gossip resulted in higher cooperation. Of even greater interest, gossip affected the players' perceptions of others even when they had access to firsthand information.14

Human society today is so big that its dimensions have outgrown our brains. We have an increasing number of people and norms. What tool could help us gossip in a group this size? Nowadays we keep track of and distribute unprecedented amounts of information via our computers: for example, journalists, interest groups, and ordinary citizens can access the U.S. Environmental Protection Agency's Toxics Release Inventory database online to identify and shame polluters. Between the database's inception in 1988 and 1995, releases of 330 toxic chemicals on the list have declined by 45 percent.15 After the retailer Trader Joe's was unresponsive to requests by the nonprofit group Greenpeace to stop selling unsustainable seafood, Greenpeace coordinated singing-fish telephone calls or demonstrations at every Trader Joe's across the nation, using the Internet. The CEO of Trader Joe's decided to comply with Greenpeace's demands by dropping several overfished species and agreeing to sell only sustainable seafood by the end of 2012.

We can use computers to simulate some of the intimacy of tribal life, but we need humans to evoke the shame that leads to cooperation. The emergence of new tools— language, writing, the Internet—cannot completely replace the eyes. Face-to-face interactions, such as those outside Trader Joe's stores, are still the most impressive form of dissent.

So what is stopping shame from catalyzing social change? I see three main drawbacks:

1. Today's world is rife with ephemeral, or "one-off," interactions. When you know you're unlikely to run into the same situation again, there is less incentive to change your behavior. Research shows, however, that if people know they will interact again, cooperation improves.16 Shame works better if the potential for future interaction is high. In a world of one-off interactions, we can try to compensate for anonymity with an image score, such as hygiene grade cards or eBay's seller ratings, which sends a signal to the group about an individual's or institution's degree of cooperation.

2. Today's world allows for amorphous identities. Recall the reef fish that observe Bluestreak Cleaner wrasses in the Red Sea. The wrasses seem to know they are being watched, and certain wrasses build their reputation on the small reef fish, allowing the big reef fish to observe their cooperative behavior with the small fry. Then, when the big fish comes in for its own cleaning, these wrasses eat some of the big reef fish's flesh along with its parasites, fattening themselves on their defection. To add to the confusion on the reef, False Cleanerfish (Aspidontus taeniatus) make their living by looking very similar to the Bluestreak Cleaner wrasses. They are able to approach reef fish under the guise of cooperation and then bite off pieces of fish flesh and swim away.

Many of our interactions these days are similar to the fish cleanings in the Red Sea. It's hard to keep track of who cooperates and who doesn't, especially if it's institutions you're monitoring. Enron, which in 2001 filed one of the largest bankruptcies in U.S. history, hid billions of dollars in debt in hundreds of shell firms, which bought poorly performing Enron stocks so that Enron could create a fraudulent company profile and mislead its auditors. Lehman Brothers, in the years before its 2008 collapse, used a smaller firm called Hudson Castle (of which it owned 25 percent) to shift risky investments off its books so that Hudson Castle, not Lehman Brothers, could absorb the "headline risk." Which leads us to shaming's third weakness.

3. Shaming's biggest drawback is its insufficiency. Some people have no shame. In the research my colleagues and I have conducted on first-year students involving games that require cooperation, we have found that shame does not always encourage cooperation from players who are least cooperative. This suggests that a certain fraction of a given population will always behave shamelessly, like the False Cleanerfish, if the payoff is high enough. The banks may have gone bankrupt, but the bankers got their bonuses. There was even speculation that publishing individual bankers' bonuses would lead to banker jealousy, not shame.

My colleagues and I conclude that ultimately shame is not enough to catalyze major social change. Slavery did not end because abolitionists shamed slave owners into freeing their slaves. Child labor did not stop because factories were shamed into forbidding children to work. Destruction of the ozone layer did not slow because industries were ashamed to manufacture products that contained chlorofl uorocarbons. This is why punishment remains imperative. Even if shaming were enough to bring the behavior of most people into line, governments need a system of punishment to protect the group from the least cooperative players.

Finally, consider who belongs to the group. Today we are faced with the additional challenge of balancing human interests and the interests of nonhuman life. How can we encourage cooperation among all living things when the nonhumans have no voice? Successful species will likely be those that recognize, implicitly or explicitly, life's interdependency. If humans are to succeed as a species, our collective shame over destroying other life-forms should grow in proportion to our understanding of their various ecological roles. Maybe the same attention to one another that promoted our own evolutionary success will keep us from failing the other species in life's fabric and, in the end, ourselves.

1 R. Boyd and P. J. Richerson, “Culture and the Evolution of Human Cooperation,” Proceedings of the Royal Society of London B 364 (2009), 3281–88.

2 R. Bshary, “Biting Cleaner Fish Use Altruism to Deceive Image- Scoring Client Reef Fish,” Proceedings of the Royal Society of London B 269 (2002), 2087–93.

3 M. Bateson, D. Nettle, and G. Roberts, “Cues of Being Watched Enhance Cooperation in a Real-World Setting,” Biology Letters 2 (2006), 412–14.

4 D. M. T. Fessler, “Shame in Two Cultures: Implications for Evolu- tionary Approaches,” Journal of Cognition and Culture 4 (2004), 2.

5 J. Jacquet et al., “Conserving Wild Fish in a Sea of Market Based Efforts,” Oryx 44 (2010), 45–56.

6 C. Crawford, “Green with Worry,” San Francisco Magazine, Feb- ruary 2008.

7 E. Hallstein and S. B. Villas-Boas, “Are Consumers Color Blind? An Empirical Investigation of a Traffic Light Advisory for Sustain- able Seafood,” www.escholarship.org/uc/item/29v6w5sp#page-11.

8 www.cdpr.ca.gov/docs/mill/sumpdsld.pdf.

9 This is calculated from Department of Energy statistics. U.S. oil consumption in 1990 was 17 million barrels per day and in 2010 was 22.2 million barrels per day.

10 M. Nussbaum, Hiding from Humanity: Disgust, Shame, and the Law (Princeton, N.J.: Princeton University Press, 2004).

11 http://stpetersnm.com/litter_louts.html.

12 G. Zhe and P. Leslie, “The Case in Support of Restaurant Hygiene Grade Cards,” Choices 20 (2005), 97–102.

13 See especially his Grooming, Gossip and the Evolution of Language (Cambridge, Mass.: Harvard University Press, 1997).

14 R. H. Sommerfeld et al., “Gossip as an Alternative for Direct Observation in Games of Indirect Reciprocity,” Proceedings of the National Academy of Sciences 104 (2007), 17435–40.

15 A. Fung and D. O’Rourke “Reinventing Environmental Regu- lation from the Grassroots Up: Explaining and Expanding the Success of the Toxics Release Inventory,” Environmental Management 25 (2000), 115–27.

16 M. Milinski, D. Semmann, and H. Krambeck, “Reputation Helps Solve the ‘Tragedy of the Commons,’ ” Nature 415 (2002), 424–26.