A synthesis of evidence for policy from behavioural science during COVID-19.

Scientific evidence regularly guides policy decisions1, with behavioural science increasingly part of this process2. In April 2020, an influential paper3 proposed 19 policy recommendations ('claims') detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandemic-related research articles that empirically investigated those claims. We report the scale of evidence and whether evidence supports them to indicate applicability for policymaking. Two independent teams, involving 72 reviewers, found evidence for 18 of 19 claims, with both teams finding evidence supporting 16 (89%) of those 18 claims. The strongest evidence supported claims that anticipated culture, polarization and misinformation would be associated with policy effectiveness. Claims suggesting trusted leaders and positive social norms increased adherence to behavioural interventions also had strong empirical support, as did appealing to social consensus or bipartisan agreement. Targeted language in messaging yielded mixed effects and there were no effects for highlighting individual benefits or protecting others. No available evidence existed to assess any distinct differences in effects between using the terms 'physical distancing' and 'social distancing'. Analysis of 463 papers containing data showed generally large samples; 418 involved human participants with a mean of 16,848 (median of 1,699). That statistical power underscored improved suitability of behavioural science research for informing policy decisions. Furthermore, by implementing a standardized approach to evidence selection and synthesis, we amplify broader implications for advancing scientific evidence in policy formulation and prioritization.

Adaptations to infer fitness interdependence promote the evolution of cooperation.

The evolution of cooperation is a major question in the biological and behavioral sciences. While most theoretical studies model cooperation in the context of an isolated interaction (e.g., a Prisoner's Dilemma), humans live in heterogeneous social environments, characterized by large variations in fitness interdependence-the extent to which one's fitness is affected by others. Theoretical and experimental work indicates that humans can infer, and respond to, variations in interdependence. In a heterogeneous ancestral environment, these psychological mechanisms to infer fitness interdependence could have provided a selective advantage, allowing individuals to maximize their fitness by deciding when and with whom to cooperate. Yet, to date, the link between cognitive inference, variation in fitness interdependence, and cooperation remains unclear. Here we introduce a theoretical framework to study the evolution of inference and cooperation in heterogeneous social environments, where individuals experience interactions with varying levels of corresponding interests. Using a combination of evolutionary game theory and agent-based modeling, we model the evolution of adaptive agents, who incur a cost to infer interdependence, in populations of fixed-behavior agents who always cooperate or defect. Our results indicate that natural selection could promote the evolution of psychological mechanisms to infer fitness interdependence, provided that there is enough variation in fitness interdependence to offset the cost of inference. Under certain conditions, the fixation of adaptive agents results in higher levels of cooperation. This depends crucially on the type of inference performed and the features of the interdependence landscape.

Love and hate do not modulate the attentional blink but improve overall performance.

How may feelings of love and hate impact people's attention? We used a modified Attentional Blink (AB) task in which 300 participants were asked to categorise a name representing a person towards whom they felt either hate, love, or neutral (first target) plus identify a number word (second target), both embedded in a rapidly presented stream of other words. The lag to the second target was systematically varied. Contrary to our hypothesis, results revealed that both hated and loved names resulted in higher accuracy for the second target than neutral names, which was largely independent of lag. Also, there we observed no sustained transfer effects of love and hate onto neutral name trials. The findings differ from prior research on attentional blink and transient, non-personal, stimulus-driven emotions, suggesting that interpersonal feelings activate different attention-relevant mechanisms. Relevant to future research, we speculate that love and hate are motivators of goal-directed behaviour that facilitate subsequent information processing.

Human Cooperation and the Crises of Climate Change, COVID-19, and Misinformation.

Contemporary society is facing many social dilemmas-including climate change, COVID-19, and misinformation-characterized by a conflict between short-term self-interest and longer-term collective interest. The climate crisis requires paying costs today to reduce climate-related harms and risks that we face in the future. The COVID-19 crisis requires the less vulnerable to pay costs to benefit the more vulnerable in the face of great uncertainty. The misinformation crisis requires investing effort to assess truth and abstain from spreading attractive falsehoods. Addressing these crises requires an understanding of human cooperation. To that end, we present (a) an overview of mechanisms for the evolution of cooperation, including mechanisms based on similarity and interaction; (b) a discussion of how reputation can incentivize cooperation via conditional cooperation and signaling; and (c) a review of social preferences that undergird the proximate psychology of cooperation, including positive regard for others, parochialism, and egalitarianism. We discuss the three focal crises facing our society through the lens of cooperation, emphasizing how cooperation research can inform our efforts to address them.

Costs, needs, and integration efforts shape helping behavior toward refugees.

Recent political instabilities and conflicts around the world have drastically increased the number of people seeking refuge. The challenges associated with the large number of arriving refugees have revealed a deep divide among the citizens of host countries: one group welcomes refugees, whereas another rejects them. Our research aim is to identify factors that help us understand host citizens' (un)willingness to help refugees. We devise an economic game that captures the basic structural properties of the refugee situation. We use it to investigate both economic and psychological determinants of citizens' prosocial behavior toward refugees. In three controlled laboratory studies, we find that helping refugees becomes less likely when it is individually costly to the citizens. At the same time, helping becomes more likely with the refugees' neediness: helping increases when it prevents a loss rather than generates a gain for the refugees. Moreover, particularly citizens with higher degrees of prosocial orientation are willing to provide help at a personal cost. When refugees have to exert a minimum level of effort to be eligible for support by the citizens, these mandatory "integration efforts" further increase prosocial citizens' willingness to help. Our results underscore that economic factors play a key role in shaping individual refugee helping behavior but also show that psychological factors modulate how individuals respond to them. Moreover, our economic game is a useful complement to correlational survey measures and can be used for pretesting policy measures aimed at promoting prosocial behavior toward refugees.

Coping with noise in social dilemmas: Group representatives fare worse than individuals because they lack trust in others' benign intentions.

Research on interindividual-intergroup discontinuity has illuminated distinct patterns of cognition, motivation, and behavior in interindividual versus intergroup contexts. However, it has examined these processes in laboratory environments with perfect transparency, whereas real-life interactions are often characterized by noise (i.e., misperceptions and unintended errors). This research compared interindividual and intergroup interactions in the presence or absence of noise. In a laboratory experiment, participants played 35 rounds of a dyadic give-some dilemma, in which they acted as individuals or group representatives. Noise was manipulated, such that players' intentions either were perfectly translated into behavior or could deviate from their intentions in certain rounds (resulting in less cooperative behavior). Noise was more detrimental to cooperation in intergroup contexts than in interindividual contexts, because (a) participants who formed benign impressions of the other player coped better with noise, and (b) participants were less likely to form such benign impressions in intergroup than interindividual interactions.

CLASH: Climate (change) and cultural evolution of intergroup conflict.

Aggression and violence levels generally increase as one moves closer to the equator, but why? We developed a new theoretical model, CLimate, Aggression, and Self-control in Humans (CLASH; van Lange, Rinderu, & Bushman, 2017b, 2017c), to understand differences within and between countries in aggression and violence in terms of differences in climate. Colder temperatures, and especially larger degrees of seasonal variation in climate, call for individuals and groups to adopt a slower life history strategy, revealed in a greater focus on the future (vs. present) and a stronger focus on self-control-variables that are known to inhibit aggression and violence. Other variables (e.g., wealth, income inequality, parasite stress) are also linked to both climate differences and to aggression and violence differences. When people think of the consequences of climate change, they rarely think of the impact on aggression and violence levels, but they should. CLASH has broad implications for the effects of climate change on intergroup conflict.

Political Ideology, Trust, and Cooperation: In-group Favoritism among Republicans and Democrats during a US National Election.

Theories suggest that political ideology relates to cooperation, with conservatives being more likely to pursue selfish outcomes, and liberals more likely to pursue egalitarian outcomes. In study 1, we examine how political ideology and political party affiliation (Republican vs. Democrat) predict cooperation with a partner who self-identifies as Republican or Democrat in two samples before (n = 362) and after (n = 366) the 2012 US presidential election. Liberals show slightly more concern for their partners' outcomes compared to conservatives (study 1), and in study 2 this relation is supported by a meta-analysis (r = .15). However, in study 1, political ideology did not relate to cooperation in general. Both Republicans and Democrats extend more cooperation to their in-group relative to the out-group, and this is explained by expectations of cooperation from in-group versus out-group members. We discuss the relation between political ideology and cooperation within and between groups.

The Road to Bribery and Corruption.

Major forms of corruption constitute a strong threat to the functioning of societies. The most frequent explanation of how severe corruption emerges is the slippery-slope metaphor-the notion that corruption occurs gradually. While having widespread theoretical and intuitive appeal, this notion has barely been tested empirically. We used a recently developed paradigm to test whether severely corrupt acts happen gradually or abruptly. The results of four experimental studies revealed a higher likelihood of severe corruption when participants were directly given the opportunity to engage in it (abrupt) compared with when they had previously engaged in minor forms of corruption (gradual). Neither the size of the payoffs, which we kept constant, nor evaluations of the actions could account for these differences. Contrary to widely shared beliefs, sometimes the route to corruption leads over a steep cliff rather than a slippery slope.

Functional Interdependence Theory: An Evolutionary Account of Social Situations.

Social interactions are characterized by distinct forms of interdependence, each of which has unique effects on how behavior unfolds within the interaction. Despite this, little is known about the psychological mechanisms that allow people to detect and respond to the nature of interdependence in any given interaction. We propose that interdependence theory provides clues regarding the structure of interdependence in the human ancestral past. In turn, evolutionary psychology offers a framework for understanding the types of information processing mechanisms that could have been shaped under these recurring conditions. We synthesize and extend these two perspectives to introduce a new theory: functional interdependence theory (FIT). FIT can generate testable hypotheses about the function and structure of the psychological mechanisms for inferring interdependence. This new perspective offers insight into how people initiate and maintain cooperative relationships, select social partners and allies, and identify opportunities to signal social motives.

The Logic of Climate and Culture: Evolutionary and Psychological Aspects of CLASH.

A total of 80 authors working in a variety of scientific disciplines commented on the theoretical model of CLimate, Aggression, and Self-control in Humans (CLASH). The commentaries cover a wide range of issues, including the logic and assumptions of CLASH, the evidence in support of CLASH, and other possible causes of aggression and violence (e.g., wealth, income inequality, political circumstances, historic circumstances, pathogen stress). Some commentaries also provide data relevant to CLASH. Here we clarify the logic and assumptions of CLASH and discusses its extensions and boundary conditions. We also offer suggestions for future research. Regardless of whether none, some, or all of CLASH is found to be true, we hope it will stimulate future research on the link between climate and human behavior. Climate is one of the most presing issues of our time.

Aggression and violence around the world: A model of CLimate, Aggression, and Self-control in Humans (CLASH).

Worldwide there are substantial differences within and between countries in aggression and violence. Although there are various exceptions, a general rule is that aggression and violence increase as one moves closer to the equator, which suggests the important role of climate differences. While this pattern is robust, theoretical explanations for these large differences in aggression and violence within countries and around the world are lacking. Most extant explanations focus on the influence of average temperature as a factor that triggers aggression (The General Aggression Model), or the notion that warm temperature allows for more social interaction situations (Routine Activity Theory) in which aggression is likely to unfold. We propose a new model, CLimate, Aggression, and Self-control in Humans (CLASH), that helps us to understand differences within and between countries in aggression and violence in terms of differences in climate. Lower temperatures, and especially larger degrees of seasonal variation in climate, call for individuals and groups to adopt a slower life history strategy, a greater focus on the future (vs. present), and a stronger focus on self-control. The CLASH model further outlines that slow life strategy, future orientation, and strong self-control are important determinants of inhibiting aggression and violence. We also discuss how CLASH differs from other recently developed models that emphasize climate differences for understanding conflict. We conclude by discussing the theoretical and societal importance of climate in shaping individual and societal differences in aggression and violence.

Reputational concerns as a general determinant of group functioning.

To understand a group's (dys)functionality, we propose focusing on its members' concerns for their reputation. The examples of prosocial behavior and information exchange in decision-making groups illustrate that empirical evidence directly or indirectly suggests that reputational concerns play a central role in groups. We argue that our conceptualization fulfills criteria for a good theory: enhancing understanding, abstraction, testability, and applicability.

Observing the earth from space: Does a virtual reality overview effect experience increase pro-environmental behaviour?

Astronauts (and recently businessmen) often express a renewed sense of responsibility for taking care of the environment, after observing the overwhelming beauty of Earth from space. Despite recent attention for this "overview effect", it is unclear whether experiencing the effect directly impacts pro-environmental behaviour. Using a virtual reality experience, the current research tests in two experimental studies the direct impact of an immersive overview effect experience on both short-term and longer term subsequent pro-environmental behaviours (donating to an environmental NGO, consuming less diary and meat). Furthermore, it investigates whether the technological immersiveness of the VR experience amplifies the effect, and the mediating role of connectedness to nature. Results show no effects of the short (7 minutes) overview effect VR video on pro-environmental behaviour (Study 1). For the longer video (15 minutes, Study 2), the results showed that the most immersive experience (video featuring meditative music and voice-over) appeared to increase connection with nature and higher donation amounts to an eco-NGO, but not significantly. No effects were found for subsequent meat and dairy consumption behaviours (measured on day 2, 4, and 6). These findings contribute to a deeper understanding of the specific features determining the effectiveness of the overview effect experiences on actual pro-environmental behaviour, providing important insights to businesses and educational institutions.

The impact of generative artificial intelligence on socioeconomic inequalities and policy making.

Generative artificial intelligence (AI) has the potential to both exacerbate and ameliorate existing socioeconomic inequalities. In this article, we provide a state-of-the-art interdisciplinary overview of the potential impacts of generative AI on (mis)information and three information-intensive domains: work, education, and healthcare. Our goal is to highlight how generative AI could worsen existing inequalities while illuminating how AI may help mitigate pervasive social problems. In the information domain, generative AI can democratize content creation and access but may dramatically expand the production and proliferation of misinformation. In the workplace, it can boost productivity and create new jobs, but the benefits will likely be distributed unevenly. In education, it offers personalized learning, but may widen the digital divide. In healthcare, it might improve diagnostics and accessibility, but could deepen pre-existing inequalities. In each section, we cover a specific topic, evaluate existing research, identify critical gaps, and recommend research directions, including explicit trade-offs that complicate the derivation of a priori hypotheses. We conclude with a section highlighting the role of policymaking to maximize generative AI's potential to reduce inequalities while mitigating its harmful effects. We discuss strengths and weaknesses of existing policy frameworks in the European Union, the United States, and the United Kingdom, observing that each fails to fully confront the socioeconomic challenges we have identified. We propose several concrete policies that could promote shared prosperity through the advancement of generative AI. This article emphasizes the need for interdisciplinary collaborations to understand and address the complex challenges of generative AI.

What we should expect from theories in social psychology: truth, abstraction, progress, and applicability as standards (TAPAS).

The construction and development of theory is one of the central routes to scientific progress. But what exactly constitutes a good theory? What is it that people might expect from an ideal theory? This article advances a new model, which delineates truth, abstraction, progress, and applicability as standards (TAPAS) for a good theory. After providing the rationale for TAPAS, this article evaluates several social-psychological theories in terms of TAPAS, especially classic theories, and illustrates its utility with some more recent theoretical contributions of social psychology. This article concludes by outlining recommendations for effective theory construction and development, such as the utility of meta-analytic approaches for pursuing truth, the utility of theory-oriented courses and journals for pursuing abstraction, and the utility of adversarial collaboration for pursuing progress, and reaching out to major personal or societal issues for pursuing applicability.

Lost in between crises: How do COVID-19 threats influence the motivation to act against climate change and the refugee crisis?

While the COVID-19 pandemic has been found to undermine mental health, it is unclear how it may impact individuals' motivation to tackle other global crises. There are at least two perspectives on how COVID-19 might psychologically impact how people respond to other global crises. The finite-pool-of-worry hypothesis suggests that worrying about one issue might diminish worry about other issues since individuals have a limited capacity of worry. Conversely, the affect-generalization hypothesis advocates that worry about an issue might generalize to other issues and increase general levels of worry. To test these competing hypotheses, the present research investigated how threats activated by the COVID-19 pandemic might affect individuals' interest in and motivation to address climate change (Study 1) and the refugee crisis (Study 2) by assessing pro-environmental behavior and prosocial behavior toward refugees, respectively. The results showed that exposure to COVID-19 threats elevated anxiety levels, and trait anxiety, psychological distance, and future orientation moderated this effect. While COVID-19 threats did not influence pro-environmental and prosocial behavior and intentions, exploratory analyses uncovered that being psychologically closer to COVID-19 might predict an increase in pro-environmental and prosocial behavior and intentions, pointing to the affect-generalization hypothesis.

Reputation Reminders: When do Eye Cues Promote Prosocial Behavior?

The watching eyes effect has gained significant attention in recent years both from scientists and from policy makers and professionals in the field. The phenomenon posits that the mere presence of eye cues can promote prosocial behavior. However, there is a growing debate about the generality of the effect across various measures and contexts. This review seeks to combine various distinct -and formerly isolated- perspectives by identifying four key components for effective interventions based on the watching eyes effect: Anonymity, crowdedness, costs, and exposure. Eye cues need to reduce perceived anonymity, be placed in non-crowded places, target low-cost prosocial acts and appear for a short amount of time. Next to these conditions, we discuss implications for other cues to reputation and recommend directions that will stimulate further research and applications in society.

The moral significance of prosstecting environmental and cultural objects.

A powerful avenue through which to promote the preservation of the natural and cultural environment is to afford cultural and environmental objects moral significance. In this research, we examine a range of factors that may give rise to moral concern regarding the protection of culturel and environmental objects as ends in themselves. In this way, we also extend theorizing and evidence beyond a focus on sentience as a focal determinant of moral significance Across five studies we show that non-sentient objects can sometimes be viewed as possessing intrinsically valuable properties that afford them moral standing (independent of their extrinsic/means-end value or any perception of their capacity to think and feel). People judge it morally wrong to harm things that are beautiful, sacred, rare, or old, and this cannot be explained merely by their usefulness or economic value. Our findings provide new insight into ways to elevate the protection of natural and cultural objects to an issue of moral significance, and suggest avenues through which to motivate the preservation of a natural and cultural environments.

Enriching Psychology by Zooming Out to General Mindsets and Practices in Natural Habitats.

Psychology has been "zooming in" on individuals, dyads, and groups with a narrow lens to the exclusion of "zooming out," which involves placing the targeted phenomena within more distal layers of influential context. Here, we plea for a paradigm shift. Specifically, we showcase largely hidden scientific benefits of zooming out by discussing worldwide evidence on inhabitants' habitual adaptations to colder-than-temperate and hotter-than-temperate habitats. These exhibits reveal two different types of theories. Clement-climate perspectives emphasize that generic common properties of stresses from cold and hot temperatures elicit similar effects on personality traits and psychosocial functioning. Cold-versus-heat perspectives emphasize that specific unique properties of stresses from cold and hot habitats elicit different effects on phenomena, such as speech practices and intergroup discrimination. Both zooming-out perspectives are then integrated into a complementary framework that helps identify explanatory mechanisms and demonstrates the broader added value of embedding zooming-in approaches within zooming-out approaches. Indeed, zooming out enriches psychology.