The human brain has evolved for group living [1]. Yet we know so little about how it supports dynamic group interactions that the study of real-world social exchanges has been dubbed the "dark matter of social neuroscience" [2]. Recently, various studies have begun to approach this question by comparing brain responses of multiple individuals during a variety of (semi-naturalistic) tasks [3-15]. These experiments reveal how stimulus properties [13], individual differences [14], and contextual factors [15] may underpin similarities and differences in neural activity across people. However, most studies to date suffer from various limitations: they often lack direct face-to-face interaction between participants, are typically limited to dyads, do not investigate social dynamics across time, and, crucially, they rarely study social behavior under naturalistic circumstances. Here we extend such experimentation drastically, beyond dyads and beyond laboratory walls, to identify neural markers of group engagement during dynamic real-world group interactions. We used portable electroencephalogram (EEG) to simultaneously record brain activity from a class of 12 high school students over the course of a semester (11 classes) during regular classroom activities (Figures 1A-1C; Supplemental Experimental Procedures, section S1). A novel analysis technique to assess group-based neural coherence demonstrates that the extent to which brain activity is synchronized across students predicts both student class engagement and social dynamics. This suggests that brain-to-brain synchrony is a possible neural marker for dynamic social interactions, likely driven by shared attention mechanisms. This study validates a promising new method to investigate the neuroscience of group interactions in ecologically natural settings.

Political debate concerning moralized issues is increasingly common in online social networks. However, moral psychology has yet to incorporate the study of social networks to investigate processes by which some moral ideas spread more rapidly or broadly than others. Here, we show that the expression of moral emotion is key for the spread of moral and political ideas in online social networks, a process we call "moral contagion." Using a large sample of social media communications about three polarizing moral/political issues (n = 563,312), we observed that the presence of moral-emotional words in messages increased their diffusion by a factor of 20% for each additional word. Furthermore, we found that moral contagion was bounded by group membership; moral-emotional language increased diffusion more strongly within liberal and conservative networks, and less between them. Our results highlight the importance of emotion in the social transmission of moral ideas and also demonstrate the utility of social network methods for studying morality. These findings offer insights into how people are exposed to moral and political ideas through social networks, thus expanding models of social influence and group polarization as people become increasingly immersed in social media networks.O ur sense of right and wrong shapes our daily interactions in a variety of domains such as political participation, consumer choices, and close relationships. What factors inform our intuitions about morality? Influential theories in psychology maintain that our moral sense is shaped by the social world (1), insofar as decades of research demonstrate that social communities influence moral development in children (2) and account for cross-cultural variation in moral beliefs (3). Furthermore, social information serves as input for cognitive and emotional processes in moral judgment and decision-making (4).Despite a broad consensus that morality is influenced by attitudes and norms transmitted by our social world, remarkably little work has examined how social networks transmit moral attitudes and norms. Most existing research takes a dyadic perspective to study the social transmission of morality; typically, one person (such as a child) is exposed to another's ideas (e.g., parent) through behavior or communication (1, 2). In society, the transmission of morality goes well beyond the dyad. Our moods, thoughts, and actions are shaped by the entire network of individuals with whom we share direct and indirect relationships (5). Thus, we often develop similar ideas and intuitions as others because we are socially connected to them (6). This phenomenon is often deemed social "contagion" because it mimics the spread of disease. We use a social contagion perspective to illuminate how morally tinged messages about political issues are transmitted through social networks.Research on the emotional underpinnings of morality provides a theoretical framework to understand the processes that may drive social contagion in the domain of morality. Emotions...

A poisonous cocktail of othering, aversion, and moralization poses a threat to democracy

Democracies assume accurate knowledge by the populace, but the human attraction to fake and untrustworthy news poses a serious problem for healthy democratic functioning. We articulate why and how identification with political parties - known as partisanship - can bias information processing in the human brain. There is extensive evidence that people engage in motivated political reasoning, but recent research suggests that partisanship can alter memory, implicit evaluation, and even perceptual judgments. We propose an identity-based model of belief for understanding the influence of partisanship on these cognitive processes. This framework helps to explain why people place party loyalty over policy, and even over truth. Finally, we discuss strategies for de-biasing information processing to help to create a shared reality across partisan divides.

Rather, ecological variables are necessary to examine structural, contextual, and sociological effects on human behavior and disease development. Schwartz, 1994 b, p. 823 Many attempts have been made to define (e.g., Rohner, 1984) and then to measure culture. Given the classic definition of culture provided by Kroeber and Kluckhohn (1952), this mapping has usually been made by using values. The most widely known value mapping is the work of Hofstede (1980), whose four value dimensions of Individualism-Collectivism, Power Distance, Uncertainty Avoidance, and Masculinity-Femininity are used as organizing and explanatory constructs in many disciplines. Tapping values salient to Chinese people, the Chinese Culture Connection (1987) has identified one additional dimension to the Hofstede four: Confucian Work Dynamism, or short-term versus long-term orientation (Hofstede, 1991). All five dimensions of culture-level values have provided the conceptual impetus for numerous cross-cultural studies. Several major cross-cultural projects have been conducted subsequent to Hofstede's (1980) groundbreaking work. With his theory-derived value survey, Schwartz (1994 a) has identified seven culture-level dimensions, namely, Conservatism, Intellectual Autonomy, Affective Autonomy, Hierarchy, Egalitarian Commitment, Mastery, and Harmony. Smith, Dugan, and Trompenaars (1996) have identified two reliable value dimensions at the cultural level from their analysis of managerial values: Egalitarian Commitment versus Conservatism, and Utilitarian Involvement versus Loyal Involvement. Smith and Bond (1998, Ch. 3) concluded that these different value surveys have produced convergent results, lending support to the validity of the cultural dimensions originally identified by Hofstede (1980). Recently, House and his associates (2003) have orchestrated a major project to identify cultural dimensions across 62 countries. A distinctive feature of this multicultural project is that values associated with leadership were measured concurrently with ideal and actual leadership behaviors. The House team has identified nine culture-level dimensions: