Local competition increases people's willingness to harm others

Investigating the effects of social information on spite in an online game

While humans are highly cooperative, they can also behave spitefully. Yet spite remains understudied. Spite can be normatively driven and while previous experiments have found some evidence that cooperation and punishment may spread via social learning, no experiments have considered the social transmission of spiteful behaviour. Here we present an online experiment where, following an opportunity to earn wealth, we asked participants to choose an action towards an anonymous partner across a full spectrum of social behaviour, from spite to altruism. In accordance with cultural evolutionary theory, participants were presented with social information that varied in source and content. Across six conditions, we informed participants that either the majority or the highest earner had chosen to behave spitefully, neutrally or altruistically. We found an overall tendency towards altruism, but at lower levels among those exposed to spite compared with altruism. We found no difference between social information that came from the majority or the highest earner. Exploratory analysis revealed that participants' earnings negatively correlated with altruistic behaviour. Our results contrast with previous literature that report high rates of spite in experimental samples and a greater propensity for individuals to copy successful individuals over the majority.

Ingroup favoritism on perceived risk of infectious diseases

Humans live in social groups; thus, infectious diseases may threaten human health and safety. Do individuals exhibit ingroup favoritism or ingroup devaluation when faced with varying risks of infectious diseases? We generated relatively realistic disease scenarios to examine this question. We reported the results from three experiments in which we tested individuals' perceived disease risk from ingroup and outgroup members under high- and low-risk conditions. Experiment 1 used a realistic influenza scenario, and Experiments 2 and 3 used a realistic scenario of exposure to coronavirus disease 2019 (COVID-19). All three experiments showed that perceived disease risk was significantly lower from ingroup members than from outgroup members and significantly lower in low-risk conditions than in high-risk conditions. Furthermore, the perceived disease risk was significantly lower from ingroup members than from outgroup members in high-risk conditions but did not significantly differ in low-risk conditions, as in Experiment 1's influenza scenario and Experiment 2's COVID-19 vaccination scenario. This suggests that ingroup favoritism is flexible. The results support ingroup favoritism and the functional flexibility principle in response to disease threats according to perceived disease risk.

Punishment: one tool, many uses

Humans are outstanding in their ability to cooperate with unrelated individuals, and punishment - paying a cost to harm others - is thought to be a key supporting mechanism. According to this view, cooperators punish defectors, who respond by behaving more cooperatively in future interactions. However, a synthesis of the evidence from laboratory and real-world settings casts serious doubts on the assumption that the sole function of punishment is to convert cheating individuals into cooperators. Instead, punishment often prompts retaliation and punishment decisions frequently stem from competitive, rather than deterrent motives. Punishment decisions often reflect the desire to equalise or elevate payoffs relative to targets, rather than the desire to enact revenge for harm received or to deter cheats from reoffending in future. We therefore suggest that punishment also serves a competitive function, where what looks like spiteful behaviour actually allows punishers to equalise or elevate their own payoffs and/or status relative to targets independently of any change in the target's behaviour. Institutions that reduce or remove the possibility that punishers are motivated by relative payoff or status concerns might offer a way to harness these competitive motives and render punishment more effective at restoring cooperation.

Disease Threat and the Functional Flexibility of Ingroup Derogation

While the findings from previous studies directly relate the ingroup derogation phenomenon to the evolved response of the behavioral immune system, there are three major limitations in the previous studies on the functional flexibility of ingroup derogation. The present study further investigated the functional flexibility of ingroup derogation by conducting three behavioral experiments on Chinese participants. In Experiment 1, we tested whether exposing to situational disease primes leads to an exaggerated ingroup derogation attitude by adopting a more rigorous control. In Experiment 2, we manipulated the source of disease threats to test whether the ingroup derogation mechanism adjusts its response according to the specific perceived vulnerabilities to the disease threats posed by ingroup and outgroup members. In Experiment 3, we tested whether recent illness promotes the expression of ingroup derogation attitudes. Results of the three experiments consistently showed that, the Chinese participants adjusted their ingroup derogation attitudes according to the external environmental disease cues (Experiments 1 and 2) and the internal physiological disease cues (Experiment 3). The results also showed that the ingroup derogation mechanism was sensitive to the specific perceived vulnerabilities to the ingroup disease threat and the outgroup disease threat (Experiment 2). Taken together, these results support the evolutionary hypothesis of ingroup derogation and suggest that the ingroup derogation found in East Asian cultures could be accounted by a functionally flexible disease-avoidance mechanism.

The Influence of Competition on Motivation to Fake in Employment Interviews

Abstract. Many applicants fake, or intentionally misrepresent information, in employment interviews. Recent theories of faking propose that applicants may fake more when there are situational cues that signal intense competition for the job. We tested this proposition by manipulating the number of competitors and selection ratio in selection scenarios, and assessed individuals’ faking intentions. We also examined whether Honesty-Humility moderated the relation between competition and faking intentions. Hypotheses were tested using a between-subjects study with 775 participants. Results show that faking intentions increased with few competitors and a small selection ratio. Honesty-Humility did not moderate the relation between competition and faking intentions. Findings support competition as a situational predictor of faking intentions, lending support to models of faking.

Local Competition Amplifies the Corrosive Effects of Inequality

Inequality is widely believed to incite conflict, but the evidence is inconsistent. We argue that the spatial scale of competition-the extent to which individuals compete locally, with their interaction partners, or globally, with the entire population-can help settle the question. We built a mathematical model of the evolution of conflict under inequality and tested its predictions in an experimental game with 1,205 participants. We found that inequality increases conflict, destroys wealth, and engenders risk taking. Crucially, these effects are amplified by local competition. Thus, inequality is at its most damaging when it arises between close competitors. Indeed, at the extremes, the combined effects of inequality and the scale of competition are very large. More broadly, our findings suggest that disagreements in the literature may be the result of a mismatch between the scale at which inequality is measured and the scale at which conflict occurs.

A Price Paid for Our Internal Strife: Escalated Intragroup Aggression and the Evolution of Ingroup Derogation

From evolutionary reasoning, we derived a novel hypothesis that ingroup derogation is an adaptation to a special ecological condition in which the greater threat of aggression is incurred by ingroup members. This hypothesis was tested and supported across five studies. Specifically, the computational modeling found that ingroup derogation could easily evolve if the chance of death incurred by intragroup conflicts was no less than 10%. Further behavioral experiments on Chinese participants showed that the ingroup derogation mechanism responded to heuristic social category cues and it responded more strongly when participants subjectively felt more vulnerable to interpersonal aggression, or when there were contextual cues of aggression in the immediate environment. Additional results showed that Chinese participants responded more strongly to aggression cues originating from ingroup members and that they endorsed more ingroup derogation attitudes even when the ingroup and outgroup members were both displaying cues of aggression. In addition, the results also revealed that the Chinese participants perceived more intentions of aggression from ingroup members than from outgroup members even in the absence of any clear signs of those intentions, and such a bias was positively correlated with ingroup derogation attitudes. Taken together, these results suggest that ingroup derogation is related to the evolved response of intragroup aggression management system.