From Australia to the Arctic, human groups engage in synchronous behaviour during communal rituals. Because ritualistic synchrony is widespread, many argue that it is functional for human groups, encouraging large-scale cooperation and group cohesion. Here, we offer a more nuanced perspective on synchrony's function. We review research on synchrony's prosocial effects, but also discuss synchrony's antisocial effects such as encouraging group conflict, decreasing group creativity and increasing harmful obedience. We further argue that a tightness–looseness (TL) framework helps to explain this trade-off and generates new predictions for how ritualistic synchrony should evolve over time, where it should be most prevalent, and how it should affect group well-being. We close by arguing that synthesizing the literature on TL with the literature on synchrony has promise for understanding synchrony's role in a broader cultural evolutionary framework. This article is part of the theme issue ‘Ritual renaissance: new insights into the most human of behaviours'.

No abstract

No abstract

The perception of gender and age of unfamiliar faces is reported to vary idiosyncratically across retinal locations such that, for example, the same androgynous face may appear to be male at one location but female at another. Here, we test spatial heterogeneity for the recognition of the identity of personally familiar faces in human participants. We found idiosyncratic biases that were stable within participants and that varied more across locations for low as compared to high familiar faces. These data suggest that like face gender and age, face identity is processed, in part, by independent populations of neurons monitoring restricted spatial regions and that the recognition responses vary for the same face across these different locations. Moreover, repeated and varied social interactions appear to lead to adjustments of these independent face recognition neurons so that the same familiar face is eventually more likely to elicit the same recognition response across widely separated visual field locations. We provide a mechanistic account of this reduced retinotopic bias based on computational simulations.

During the COVID-19 pandemic, individuals have depended on risk information to make decisions about everyday behaviors and public policy. In this online informational intervention, we assessed whether an interactive website influenced individuals' risk tolerance to support public health goals. We collected data from 10,891 unique users who interacted with the online COVID-19 Event Risk Tool (https://covid19risk.biosci.gatech.edu/), which featured interactive elements (a dynamic risk map, survey questions, and a risk quiz with accuracy feedback). After learning about the risk of COVID-19 exposure, participants reported being less willing to participate in potentially risky events. This increase in risk aversion was most pronounced for large event sizes and for individuals who had underestimated risk. We also uncovered a bias in risk estimation: Participants tended to overestimate the risk of small events, but underestimate the risk of large events. Our results bear implications for risk communication and insights for broader research on risky decision-making.

Culture plays a significant role in determining what people believe and claim to know. Here, we argue that, in addition to shaping what people come to know, culture influences the accessibility of that knowledge. In five studies, we examined how activating participants' American identities (a cultural identity) influenced their ability to retrieve well-known information: the 50 U. S. states. Activating participants' American identities-relative to other identities-led them to retrieve more U. S. states over brief periods of time; the effect disappeared over longer periods of time. Overall, our results suggest that the identity activated affects the speed with which relevant knowledge is retrieved, but that the effect is not large in magnitude (perhaps contributing to why we did not find the effect in Study 4). This work provides the first evidence that cultural identity influences not only what one knows but also its accessibility.

Personal familiarity facilitates rapid and optimized detection of faces. In this study, we investigated whether familiarity associated with faces can also facilitate the detection of facial expressions. Models of face processing propose that face identity and face expression detection are mediated by distinct pathways. We used a visual search paradigm to assess if facial expressions of emotion (anger and happiness) were detected more rapidly when produced by familiar as compared to unfamiliar faces. We found that participants detected an angry expression 11% more accurately and 135 ms faster when produced by familiar as compared to unfamiliar faces while happy expressions were detected with equivalent accuracies and at equivalent speeds for familiar and unfamiliar faces. These results suggest that detectors in the visual system dedicated to processing features of angry expressions are optimized for familiar faces.

During the COVID-19 pandemic, political partisanship has influenced information consumption, beliefs, and health behaviors. Communicating accurate information about COVID-19 exposure risk is crucial for empowering individuals to make informed decisions. In the present study, we used social media advertisements to experimentally test the efficacy of five messages about COVID-19 risks (varying the context specificity and emotional valence) across six demographic groups (N=221,829; stratified by age group and political leaning). Advertisements that emphasized local risk levels for specific scenarios were most effective, across all demographic groups. Emotional valence did not significantly influence user engagement. Although conservatives were less likely than liberals to engage with COVID-19 information after clicking on an advertisement, conservatives who did engage with our informational intervention responded beneficially and became less willing to take risks. Overall, evoking specific scenarios motivated information seeking about COVID-19, overcoming the political divide to facilitate risk communication and change behavioral intentions.