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  • Norm Change: Trendsetters and Social Structure
  • Cristina Bicchieri (bio) and Alexander Funcke (bio)

the explanation of social norms change faces two main challenges. One is to define precisely what social norms are. The social science literature is not very precise in this respect, as different collective behaviors often are conflated under the label “norm.” Here we adopt a definition of social norms (Bicchieri 2006, 2016) that lets us specify the necessary elements of norm change. The other challenge is to understand the mechanisms of norm dynamics. Both individual actions and social structure play a role in norm emergence and change, as the network structure within which individuals interact may foster or even prevent social change. Moreover, individuals are heterogeneous in many respects, including norm conformity. Heterogeneous individuals have different thresholds for action, and thus understanding norm change requires a fine-grained analysis of the distribution of heterogeneous types in a population.

In this paper, we focus on norm abandonment and examine the role played by the initiators of norm abandonment—“trendsetters”—in spearheading change. We highlight the characteristics that make someone a potential trendsetter, model a social norm game where choices are determined by such characteristics, and show with simulations based on our model how the network that trendsetters interact with may help or hinder norm change. [End Page 1]


We define a social norm as a rule of behavior that individuals prefer to conform to on the conditions that they believe (a) that most people in their reference network conform to it (empirical expectation), and (b) that most people in their reference network believe they ought to conform to it (normative expectation) (Bicchieri 2006). These expectations always refer to a specific group of people whose behavior and approval matter to the individual in question. This is the reference network we need to uncover when studying the dynamics of norms.

Also note that the preference for conformity is conditional on having certain social expectations. If our social expectations change, we would no longer be in the grip of the norm. This is one of the main features that distinguish social norms from moral norms. Thus we may obey a social norm that we dislike if our empirical and normative expectations lie in favor of the norm.

Normative expectations are often accompanied by the belief that we will be punished if we do not conform. Indeed, if others believe one ought to conform, the reaction to nonconformity may range from slight displeasure to active or even extreme punishment. It must then be the case that when a norm is well established in a community, the utility of conformity increases with the number of norm-followers, and decreases as the number of conformists dwindles. Abandoning an established norm is a risky endeavor.


When a social norm is present, the actions of individuals are dependent on each other, since individual choices depend on expectations of what relevant others do and approve of. Hence, changing a norm must involve a collective change of both empirical and normative expectations. Transgressing a norm is costly, so we usually observe a slow change in empirical expectations as people observe few initial transgressors. Once a tipping point is reached, we see a cascade of behavioral change, and at that point, normative expectations are abandoned. [End Page 2]

Norm change may occur in many ways, but the presence of first movers who are willing to spark it can exert a major influence. What type of individual will end up initiating change? In other words, what sort of individual will be prepared to bear a cost—sometimes a significant one—to initiate norm change?

It is important to note that here we are only analyzing a situation where a norm is well established and not those cases in which a new norm may be introduced, even though sometimes norm abandonment may be followed by the creation of a new norm. We believe the dynamics of change may be different in these two cases (Bicchieri 2016).

Note also that different individuals will be willing to abandon a norm under different circumstances. One person might be willing to forsake a norm even if she believes only a few people...