Evolution of social norms and correlated equilibria

Abstract

Social norms regulate and coordinate most aspects of human social life, yet they emerge and change as a result of individual behaviors, beliefs, and expectations. A satisfactory account for the evolutionary dynamics of social norms, therefore, has to link individual beliefs and expectations to population-level dynamics, where individual norms change according to their consequences for individuals. Here, we present a model of evolutionary dynamics of social norms that encompasses this objective and addresses the emergence of social norms. In this model, a norm is a set of behavioral prescriptions and a set of environmental descriptions that describe the expected behaviors of those with whom the norm holder will interact. These prescriptions and descriptions are functions of exogenous environmental events. These events have no intrinsic meaning or effect on the payoffs to individuals, yet beliefs/superstitions regarding them can effectuate coordination. Although a norm’s prescriptions and descriptions are dependent on one another, we show how they emerge from random accumulations of beliefs. We categorize the space of social norms into several natural classes and study the evolutionary competition between these classes of norms. We apply our model to the Game of Chicken and the Nash Bargaining Game. Furthermore, we show how the space of norms and evolutionary stability are dependent on the correlation structure of the environment and under which such correlation structures social dilemmas can be ameliorated or exacerbated.

Changes in Mental Health and Preventive Behaviors before and after COVID-19 Vaccination: A Propensity Score Matching (PSM) Study

“…The demographic variables in this study were the following factors: biological sex (male or female), education level (junior high school or below, high school, bachelor, master or above), family monthly per capita income (RMB <5000, RMB 5000–10,000, RMB 10,001–15,000, RMB >15,000), health condition (very good, good, general, poor, very poor), influenza vaccination history in the past 3 years (no vaccination, irregular vaccination, regular vaccination), domestic business trip frequency (at least twice a month, once a month, once every 3 months, once every 6 months), and first shot time of COVID-19 vaccine (waiting to receive the first shot or just vaccinated, 2 weeks ago, 1 month ago, 3 months ago, 6 months ago). Previous studies have indicated that changes in psychological and behavioral performance usually occur after a period of vaccination [ 27 , 28 , 29 , 30 ]. As a result, the control group (pre-vaccination) was defined as those who were waiting to receive the first shot or were just vaccinated, while those who had been vaccinated more than 2 weeks were defined as the vaccine treatment group (post-vaccination) in our study.…”

False beliefs can bootstrap cooperative communities through social norms

“…Between the concepts of homo economicus and homo socialis, there is a middle ground where individuals have evolved preferences and acquired social norms that nonetheless are subject to "rational" optimization with constraints (Fehr and Fischbacher, 2002;Gintis, 2007;Akçay et al, 2009;Alger and Weibull, 2013;Gintis, 2014;Morsky and Akçay, 2019).…”

“…Social norms can be defined as the rules of the game in social interactions (Bicchieri, 2006 (Gelfand and Jackson, 2016), yet humans have innate predisposition for internalizing culturally acquired norms (Gintis, 2003). Such social norms can instigate group-beneficial behaviors (Gintis, 2003;Gavrilets and Richerson, 2017;Akçay and Van Cleve, 2019) or coordinate social behaviors for mutual gain (Gintis, 2010;Morsky and Akçay, 2019). Importantly, adopting a social norm does not mean that individuals blindly follow them: rather, social norms frequently act to shape preferences or default behaviors of individuals, who still make decisions that are responsive to their payoffs or other signals and beliefs.…”

False beliefs can bootstrap cooperative communities through social norms

“…The content of these norms evolves culturally (Gelfand & Jackson, 2016), yet humans have an innate predisposition for internalising culturally acquired norms (Gintis, 2003). Such social norms can instigate group-beneficial behaviours (Akçay & Van Cleve, 2021;Gavrilets & Richerson, 2017;Gintis, 2003) or coordinate social behaviours for mutual gain (Gintis, 2010;Morsky & Akçay, 2019).…”