How do humans search for rewards in unfamiliar environments, where not all options can be exhaustively explored? Wu et al. show how a combination of generalization and optimistic sampling guides efficient human exploration in complex environments.

See Wu et al.

How do jurors and other legal professionals form judgements of guilt? Pearson et al. introduce an approach that combines a high-throughput experimental design and statistical modelling to show how much jurors and lawyers weigh different types of crime and evidence when assessing the guilt of someone accused of a crime.

See Pearson et al.

See also News and Views by Saks

Analyses of data from 211 independent, randomized controlled trials and a pre-registered experiment show that second-order normative beliefs — perceptions about what is commonly believed — play a critical role in promoting energy conservation.

See Jachimowicz et al.

Replication initiatives are fundamental for scientific progress. Camerer et al. carried out replications of 21 Science and Nature social science experiments, successfully replicating 13 of 21 studies. Effect sizes of replications were about half the size of the originals.

See Camerer et al. and News & Views by Macleod

Why did Homo sapiens become the last surviving hominin? Roberts and Stewart review evidence for human dispersal 300–12 thousand years ago and propose that humans thrived via a unique 'generalist specialist' ecological niche.

See Roberts and Stewart

Human beings rely on cooperation to survive and thrive. Understanding how and why cooperation succeeds or fails is integral to solving the many global challenges we face. In this Focus, we bring together review, opinion, and research content on human cooperation, aiming to spark interdisciplinary conversation.

See Editorial

By analysing the language of tweets around protests in Baltimore in 2015 and through behavioural laboratory experiments, Mooijman and colleagues find that moralization of protest issues leads to greater support for violence and increased violent protests.

See Mooijman et al.

How do children navigate common resource dilemmas and develop the skills necessary to overcome the tragedy of the commons? A common pool resource experiment shows that six-year-olds are collectively able to avoid collapsing a shared resource, using similar strategies to adults.

See Koomen and Herrmann

How does massive social change affect the extent of genetic influence on social outcomes? An analysis of genetic influences on educational attainment and occupation in pre- versus post-Soviet era Estonia shows that genetics has a much greater influence on social outcomes after transition to a capitalist society.

See Rimfeld et al.

How can minority cultures survive? A model of minority–majority group interactions shows that minority cultural practices can be preserved from cultural homogenization when a group boundary allows free movement of minority members, but excludes members of the more powerful majority.

See Bunce and McElreath.

Norms about hygiene and violence have become stricter over time. Strimling and colleagues develop and empirically test a formal model of this ‘civilizing process’, suggesting that norm changes come about because people who prefer stricter norms are more prone to punish transgressions.

See Strimling et al. and News & Views by Azar.

How much money is enough to be happy? Analyses of data from the Gallup World Poll show that happiness does not rise indefinitely with income. Globally, ‘income satiation’ occurs at US$95,000 for life evaluation and US$60,000–75,000 for emotional well-being.

See Jebb et al.