Social Norms and the Health of Populations

Posted on: May 1, 2016 Topics: alcohol use, dean's note, social and behavioral sciences


In 1951, psychologist Solomon Asch decided to test human conformity. He assembled a cohort of 50 male college students and put groups of eight together in a room, ostensibly to give them a “vision test.” They were presented with a single line on a page, then were asked to choose, out of a group of three additional lines, which was closest to the first in length. This was no trick question—in each case, it was clear which line was closest. Participants sat in a row and, one by one, gave their answer. What one participant did not know, however, was that everyone else had agreed to give a deliberately incorrect response. The aim of the experiment was to see how often the naive participant would, under these circumstances, acquiesce to an answer that was plainly incorrect. As it turned out, there was an average 37 percent conformity rate across all similar trials—that is, more than one-third of participants gave the wrong answer simply because everyone else around them was also giving the wrong answer.

Why did so many participants go along with the group, in denial of the evidence? The answer has much to do with social norms.

Social norms are the customary rules of behavior that govern our interactions with others. They are “common standards within a social group regarding socially acceptable or appropriate behavior in particular social situations, the breach of which has social consequences.” Social norms theory suggests that our actions can be influenced by our perceptions, or misperceptions, about how our peers think and act. Importantly, there can be a gap between perceived norms and actual norms. Perceived norms are the beliefs we think our peers have, and the behaviors we think they expect of us. Actual norms are not subjective; they entail what these beliefs genuinely are, and what sort of behaviors are truly prevalent among social groups.

This has important implications for efforts to promote the health of populations. Consider, close to home, the example of college binge drinking, a persistent health hazard affecting millions of students every year. In 2013, 59.4 percent of full-time students between the ages of 18 and 22 were reported to have drank alcohol in the past month; 12.7 percent of these students had engaged in heavy drinking, defined as an excess of five drinks on one occasion, on five or more occasions. Alcohol drinking in college has been linked to a host of challenges on college campuses, including sexual assault and accidents leading to injury or death.

Despite substantial recent attention to the issue, college binge drinking remains a stubbornly difficult problem to solve. There are data to suggest that this difficulty is perhaps more rooted in the power of social norms than in the intrinsic appeal of alcohol. College students have been shown to have a “pluralistic ignorance” of the drinking patterns of their peers, resulting in the unhealthy practice of less-committed drinkers attempting to drink more to keep pace with an incorrectly perceived norm. Put simply, when a student assumes that everyone around them is drinking, they will often conclude that they must drink too.

Interventions based on social norms theory seek to correct problematic behaviors by first understanding the degree of misperception between perceived and actual norms, then by educating populations about these misperceptions through media campaigns, with the goal of changing behavior. The utility of this approach to behavior change has been demonstrated on a number of campuses that have successfully reduced drinking by developing campaigns that portray accurate norms for alcohol consumption and non-use. As a result, at the University of Arizona, a more than 20 percent reduction in high-risk drinking was noted within three years of their campaign. At Northern Illinois University, a 44 percent reduction was noted after 10 years. In these cases, there was a correlation between positive changes in behavior and the correction of perceptions over time.

Encouraging as these successes may be, adverse behavior is not always rooted in misperceptions. Deeply rooted social norms, shared by members of a community, can be problematic in and of themselves, as in the case of Female Genital Cutting (FGC). I have commented on FGC previously. In some African communities, the practice is deeply tied to beliefs about marriageability and social inclusion. Girls who are not cut risk being shunned. Tostan, one of the leading NGOs working to eliminate FGC, determined that behavioral change could best be achieved using a two-pronged strategy. Realizing the importance of social norms, Tostan works to change the way FGC is viewed within communities, so that these communities might decide for themselves to do away with this behavior. A key aspect of Tostan’s model is their focus on changing the opinion of groups instead of individuals, targeting the social norm itself rather than any one person’s choice to follow it. The success of Tostan’s strategy is borne out by the numbers—7,375 communities in Africa have abandoned FGC.

An effective social norms change strategy, then, stands to be an essential addition to our public health armamentarium. I worry sometimes, however, that a social norms-based approach can inadvertently place too much emphasis on individual behaviors, at the expense of recognizing more fundamental drivers of population health. For example, evidence is mounting that unhealthy behaviors leading to obesity are linked with social norms. It is indeed true that the affluent are able to place a social premium on healthy eating because they can afford to, while in low-income neighborhoods the consumption of junk food is simply a fact of life. However, it is also true that poor dietary habits are facilitated by the abundance of cheap, calorie-dense, nutrient-poor food and that a focus only on social norm change, absent a focus on the foundational drivers of the conditions within which these social norms are developed, misses the point, and is almost certainly doomed to failure. I have previously wrestled with the challenge of focusing on foundations vs. mechanisms, and I note this here not to obviate one versus another, but to acknowledge the centrality of norms, and our need to tangle with them as macrosocial forces that are essential to the improvement of population health. We must not minimize the importance of the foundational structures that shape those norms. In many ways, it is equally important to recognize that the foundational structures that shape elements of our lives are themselves the products of what is normative. We accept particular economic and cultural structures because they are part of “common standards.” That is indeed where social movements have been successful in nudging, shaping, and influencing the conditions within which we live, shaping in turn the norms that influence our behavior.

Here at SPH, we have among us leaders in the application of social norms theory to the aims of public health. I am thinking, among others, of professor William DeJong’s efforts to reduce college drinking through marketing campaigns. Engagement with social norms, and an appreciation of their powerful influence on the well-being of populations, can be an important part of the work of public health, consistent with our emphasis on prevention, and our aspirations for healthier populations.

I hope everyone has a terrific week. Until next week.

Warm regards,


Sandro Galea, MD, DrPH
Dean and Robert A. Knox Professor
Boston University School of Public Health
Twitter: @sandrogalea

Acknowledgement: I am grateful for the contributions of Revathi Penumatsa, MB, BS, and Eric DelGizzo to this Dean’s Note.

Previous Dean’s Notes are archived at:

Related Profiles:

Post Your Comment