Cultural differentiation does not entail group-level structure: The case for geographically explicit analysis.

Richerson et al. argue that relatively large cultural F ST values provide evidence for group structure and therefore scope for group selection. However, recent research on spatial patterns of cultural variation demonstrates that, as in the genetic case, apparent group structure can be a consequence of geographic clines, not group barriers. Such a pattern limits the scope for cultural group selection.

National identity predicts public health support during a global pandemic.

Changing collective behaviour and supporting non-pharmaceutical interventions is an important component in mitigating virus transmission during a pandemic. In a large international collaboration (Study 1, N = 49,968 across 67 countries), we investigated self-reported factors associated with public health behaviours (e.g., spatial distancing and stricter hygiene) and endorsed public policy interventions (e.g., closing bars and restaurants) during the early stage of the COVID-19 pandemic (April-May 2020). Respondents who reported identifying more strongly with their nation consistently reported greater engagement in public health behaviours and support for public health policies. Results were similar for representative and non-representative national samples. Study 2 (N = 42 countries) conceptually replicated the central finding using aggregate indices of national identity (obtained using the World Values Survey) and a measure of actual behaviour change during the pandemic (obtained from Google mobility reports). Higher levels of national identification prior to the pandemic predicted lower mobility during the early stage of the pandemic (r = -0.40). We discuss the potential implications of links between national identity, leadership, and public health for managing COVID-19 and future pandemics.

Jumping to Conclusions About the Beads Task? A Meta-analysis of Delusional Ideation and Data-Gathering.

It has been claimed that delusional and delusion-prone individuals have a tendency to gather less data before forming beliefs. Most of the evidence for this "jumping to conclusions" (JTC) bias comes from studies using the "beads task" data-gathering paradigm. However, the evidence for the JTC bias is mixed. We conducted a random-effects meta-analysis of individual participant data from 38 clinical and nonclinical samples (n = 2,237) to investigate the relationship between data gathering in the beads task (using the "draws to decision" measure) and delusional ideation (as indexed by the "Peters et al Delusions Inventory"; PDI). We found that delusional ideation is negatively associated with data gathering (r(s) = -0.10, 95% CI [-0.17, -0.03]) and that there is heterogeneity in the estimated effect sizes (Q-stat P = .03, I(2) = 33). Subgroup analysis revealed that the negative association is present when considering the 23 samples (n = 1,754) from the large general population subgroup alone (r(s) = -0.10, 95% CI [-0.18, -0.02]) but not when considering the 8 samples (n = 262) from the small current delusions subgroup alone (r(s) = -0.12, 95% CI [-0.31, 0.07]). These results provide some provisional support for continuum theories of psychosis and cognitive models that implicate the JTC bias in the formation and maintenance of delusions.