Humans care for the wellbeing of some animals (e.g. dogs), yet tacitly endorse the maltreatment of others (e.g. pigs). What treatment we find morally appropriate for an animal depends on whether we characterise it as “pet” or “food”. Is this categorisation of animals and the resulting moral hierarchy of species present in childhood or instead taught through the lifespan? Comparing samples of children (9-11-years-old), young adults (18-21-years-old), and adults (29-59-years-old; total N=479), we find that children as compared to young adults and adults, a) show less speciesism, i.e. moral worth tied less to species-membership, b) are less likely to categorise farm animals as food than pets, c) think farm animals ought to be treated better, and d) deem eating meat and animal products less morally acceptable. These results are not due to children having a lower general acceptance of violence against living beings than adults. Our findings imply that our moral view of animal worth is not innate but instead develops over the lifespan in our specific societal context.

Most people hold that it is wrong to sacrifice some humans to save a greater number of humans. Do people also think that it is wrong to sacrifice some animals to save a greater number of animals, or do they answer such questions about harm to animals by engaging in a utilitarian cost-benefit calculation? Across 10 studies (N = 4,662), using hypothetical and real-life sacrificial moral dilemmas, we found that participants considered it more permissible to harm a few animals to save a greater number of animals than to harm a few humans to save a greater number of humans. This was explained by a reduced general aversion to harm animals compared to humans, which was partly driven by participants perceiving animals to suffer less and to have lower cognitive capacity than humans. However, the effect persisted even in cases where animals were described as having greater suffering capacity and greater cognitive capacity than some humans, and even when participants felt more socially connected to animals than to humans. The reduced aversion to harming animals was thus also partly due to speciesism—the tendency to ascribe lower moral value to animals due to their species-membership alone. In sum, our studies show that deontological constraints against instrumental harm are not absolute but get weaker the less people morally value the respective entity. These constraints are strongest for humans, followed by dogs, chimpanzees, pigs, and finally inanimate objects.

Helping others can entail risks. Doctors that treat infectious patients may risk their own health, intervening in a fight can lead to injury, and organ donations can lead to medical complications. When helping others comes with a risk to oneself, decisions depend on the individual’s valuation of others’ well-being (social preferences) and the degree of personal risk the individual finds acceptable (risk preferences). Here we identify how these distinct preferences are behaviorally (Study 1, N=292) and neurobiologically (Study 2, N=154) integrated when helping is risky. We independently assessed social and risk preferences using incentivized behavioral tasks, and manipulated dopamine and norepinephrine levels in the brain by providing methylphenidate, atomoxetine, or placebo. Results reveal that social and risk preferences are independent driving forces of risky helping, and that methylphenidate-altered dopamine concentrations lead to more helping under risk because of increases in risk-tolerance rather than increased social preferences. Implications for decision-theory and drug use are discussed.

Philosophers have argued there is a normative relationship between our attitudes towards animals (“speciesism”) and other prejudices, and psychological work suggests speciesism relies on similar psychological processes and motivations as those underlying other prejudices. But do laypeople perceive such a connection? We compared perceptions of a target who is high or low on speciesism with those of a target who is high or low on racism (Studies 1–2), sexism (Study 2), or homophobia (Study 3). We find that just like racists, sexists, and homophobes, speciesists were both evaluated more negatively and expected to hold more general prejudicial attitudes and ideologies (e.g. thought to be higher on SDO and more prejudiced in other ways). Our results suggest that laypeople seem intuitively aware of the connection between speciesism and “traditional” forms of prejudice, inferring similar personality traits and general prejudicial attitudes from a speciesist just as they do from a racist, sexist, or homophobe.

The 21st century will likely see growing risks of human extinction, but currently, relatively small resources are invested in reducing such existential risks. Using three samples (UK general public, US general public, and UK students; total N = 2,507), we study how laypeople reason about human extinction. We find that people think that human extinction needs to be prevented. Strikingly, however, they do not think that an extinction catastrophe would be uniquely bad relative to near-extinction catastrophes, which allow for recovery. More people find extinction uniquely bad when (a) asked to consider the extinction of an animal species rather than humans, (b) asked to consider a case where human extinction is associated with less direct harm, and (c) they are explicitly prompted to consider long-term consequences of the catastrophes. We conclude that an important reason why people do not find extinction uniquely bad is that they focus on the immediate death and suffering that the catastrophes cause for fellow humans, rather than on the long-term consequences. Finally, we find that (d) laypeople-in line with prominent philosophical arguments-think that the quality of the future is relevant: they do find extinction uniquely bad when this means forgoing a utopian future.

Stress changes our social behavior. Traditionally, stress has been associated with "fight-or-flight" - the tendency to attack an aggressor, or escape the stressor. But stress may also promote the opposite pattern, i.e. "tend-and-befriend" - increased prosociality toward others. It is currently unclear which situational or physiological factors promote one or the other. Here, we hypothesized that stress stimulates both tendencies, but that fight-or-flight is primarily directed against a potentially hostile outgroup, moderated by rapid-acting catecholamines, while tend-and-befriend is mainly shown towards a supportive ingroup, regulated by cortisol. To test this hypothesis, we measured stress-related neurohormonal modulators and sex hormones in male and female participants who were exposed to a psychosocial stressor, and subsequently played an intergroup social dilemma game in which they could reveal prosocial motives towards an ingroup (ingroup-love) and hostility towards an outgroup (outgroup-hate). We found no significant effects of stress on social preferences, but stress-related heart-rate increases predicted outgroup-hostile behavior. Furthermore, when controlling for testosterone, cortisol was associated with increased ingroup-love. Other-regarding behavior was overall higher in male than female participants. Our mixed results are of interest to scholars of the effects of stress on prosocial and aggressive behavior, but call for refinement in future replications.

an optimistic learning bias leads people to update their beliefs in response to better-than-expected good news but neglect worse-than-expected bad news. Because evidence suggests that this bias arises from self-concern, we hypothesized that a similar bias may affect beliefs about other people’s futures, to the extent that people care about others. Here, we demonstrated the phenomenon of vicarious optimism and showed that it arises from concern for others. Participants predicted the likelihood of unpleasant future events that could happen to either themselves or others. In addition to showing an optimistic learning bias for events affecting themselves, people showed vicarious optimism when learning about events affecting friends and strangers. Vicarious optimism for strangers correlated with generosity toward strangers, and experimentally increasing concern for strangers amplified vicarious optimism for them. These findings suggest that concern for others can bias beliefs about their future welfare and that optimism in learning is not restricted to oneself.

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.

We explore whether the known preference for default options in choice contexts-default effects-occur in altruistic contexts and the extent to which this can be explained through appeal to social norms. In four experiments, we found that (i) participants were more likely to donate money to charity when this was the default option in an altruistic choice context; (ii) participants perceived the default option to be the socially normative option; (iii) perceptions of social norms mediated the relationship between default status and charitable donations; and (iv) a transfer effect, whereby participants translated social norms they inferred from the default option in one domain into behavior in a second, related domain. Theoretically, our analysis situates default effects within a comprehensive body of social psychological research concerning social norms and the attitude-behavior relationship, providing novel empirical predictions. Practically, these findings highlight that the way donation policies are framed can have an important impact on donation behavior: in our third study, we found that 81% donated half of their earnings for taking part in the experiment to charity when this was the default option, compared with only 19% when keeping the money was the default. Our work suggests that making use of default effects could be an effective tool to increase altruistic behavior without compromising freedom.

Ingroup favoritism-the tendency to favor members of one's own group over those in other groups-is well documented, but the mechanisms driving this behavior are not well understood. In particular, it is unclear to what extent ingroup favoritism is driven by preferences concerning the welfare of ingroup over outgroup members, vs. beliefs about the behavior of ingroup and outgroup members. In this review we analyze research on ingroup favoritism in economic games, identifying key gaps in the literature and providing suggestions on how future work can incorporate these insights to shed further light on when, why, and how ingroup favoritism occurs. In doing so, we demonstrate how social psychological theory and research can be integrated with findings from behavioral economics, providing new theoretical and methodological directions for future research.

Social scientists increasingly recognize the potential of social network analysis, which enriches the explanation of human behavior by explicitly taking its social structure into account. In particular for the science of groups, social network analysis has reached a point of analytic refinement that makes it a valuable tool for investigating some of the central mechanisms that underlie intra- and intergroup behavior. The present article highlights the general relevance of this scientific approach and describes the background, generation, and application of cross-sectional as well as longitudinal network statistics that are of specific interest to group researchers. In doing so, we aim to provide a general introduction for researchers new to this approach, while demonstrating the potential and limitations of social network analysis for different areas in this field.

To what extent do people help ingroup members based on a social preference to improve ingroup members’ outcomes, versus strategic concerns about preserving their reputation within their group? and do these motives manifest differently when a prosocial behaviour occurs in the context of helping another gain a positive outcome (study 1), versus helping another to avoid losing a positive outcome (study 2)? in both contexts, we find that participants are more prosocial towards ingroup (versus outgroup members) and more prosocial when decisions are public (versus private) but find no interaction between group membership and either anonymity of the decision or expected economic value of helping. Therefore, consistent with a preference-based account of ingroup favouritism, people appear to prefer to help ingroup members more than outgroup members, regardless of whether helping can improve their reputation within their group. Moreover, this preference to help ingroup members appears to take the form of an intuitive social heuristic to help ingroup members, regardless of the economic incentives or possibility of reputation management. Theoretical and practical implications for the study of intergroup prosocial behaviour are discussed.

A primary means for the augmentation of cognitive brain functions is "pharmacological cognitive enhancement" (PCE). The term usually refers to the off-label use of medical substances to improve mental performance in healthy individuals. With the final aim to advance the normative debate taking place on that topic, several empirical studies have been conducted to assess the attitudes toward PCE in the public, i.e. in groups outside of the academic debate. In this review, we provide an overview of the 40 empirical studies published so far, reporting both their methodology and results. Overall, we find that several concerns about the use of PCE are prevalent in the public. These concerns largely match those discussed in the normative academic debate. We present our findings structured around the three most common concerns: medical safety, coercion, and fairness. Fairness is divided into three subthemes: equality of opportunity, honesty, and authenticity. Attitudes regarding some concerns are coherent across studies (e.g. coercion), whereas for others we find mixed results (e.g. authenticity). Moreover, we find differences in how specific groups-such as users, nonusers, students, parents, and health care providers-perceive PCE: a coherent finding is that nonusers display more concerns regarding medical safety and fairness than users. We discuss potential psychological explanations for these differences. © 2014 Schelle, Faulmüller, Caviola and Hewstone.

Research into cognitive biases that impair human judgment has mostly been applied to the area of economic decision-making. Ethical decision-making has been comparatively neglected. Since ethical decisions often involve very high individual as well as collective stakes, analyzing how cognitive biases affect them can be expected to yield important results. In this theoretical article, we consider the ethical debate about cognitive enhancement (CE) and suggest a number of cognitive biases that are likely to affect moral intuitions and judgments about CE: status quo bias, loss aversion, risk aversion, omission bias, scope insensitivity, nature bias, and optimistic bias. We find that there are more well-documented biases that are likely to cause irrational aversion to CE than biases in the opposite direction. This suggests that common attitudes about CE are predominantly negatively biased. Within this new perspective, we hope that subsequent research will be able to elaborate this hypothesis and develop effective de-biasing techniques that can help increase the rationality of the public CE debate and thus improve our ethical decision-making.

This theoretical paper draws the scientific community's attention to how pharmacological cognitive enhancement may impact on society and law. Namely, if safe, reliable, and effective techniques to enhance mental performance are eventually developed, then this may under some circumstances impose new duties onto people in high-responsibility professions-e.g. surgeons or pilots-to use such substances to minimize risks of adverse outcomes or to increase the likelihood of good outcomes. By discussing this topic, we also hope to encourage scientists to bring their expertise to bear on this current public debate. © 2014 Santoni de Sio, Faulmüller and Vincent.

There are numerous ways people can improve their cognitive capacities: good nutrition and regular exercise can produce long-term improvements across many cognitive domains, whilst commonplace stimulants such as coffee temporarily boost levels of alertness and concentration. Effects like these have been well-documented in the medical literature and they raise few (if any) ethical issues. More recently, however, clinical research has shown that the off-label use of some pharmaceuticals can, under certain conditions, have modest cognition-improving effects. Substances such as methylphenidate and modafinil can improve capacities such as working memory and concentration in some healthy individuals. Unlike their more mundane predecessors, these methods of "cognitive enhancement" are thought to raise a multitude of ethical issues. This paper presents the six principal ethical issues raised in relation to pharmacological cognitive enhancers (PCEs)-issues such as whether: (1) the medical safety-profile of PCEs justifies restricting or permitting their elective or required use; (2) the enhanced mind can be an "authentic" mind; (3) individuals might be coerced into using PCEs; (4), there is a meaningful distinction to be made between the treatment vs. enhancement effect of the same PCE; (5) unequal access to PCEs would have implications for distributive justice; and (6) PCE use constitutes cheating in competitive contexts. In reviewing the six principal issues, the paper discusses how neuroscientific research might help advance the ethical debate. In particular, the paper presents new arguments about the contribution neuroscience could make to debates about justice, fairness, and cheating, ultimately concluding that neuroscientific research into "personalized enhancement" will be essential if policy is to be truly informed and ethical. We propose an "ethical agenda" for neuroscientific research into PCEs. © 2014 Maslen, Faulmüller and Savulescu.

Interpersonal cognitive consistency is a driving force in group behavior. In this article, we propose a new model of interpersonal cognitive consistency in collective decision making. Building on ideas from the mutual enhancement model (Wittenbaum, Hubbell, & Zuckerman, 1999), we argue that group members evaluate one another more positively when they mention information confirming each other's preferences instead of information disconfirming these preferences. Furthermore, we argue that this effect is mediated by perceived information quality: Group members evaluate one another more positively when they mention information confirming each other's preferences because they perceive this information to be more important and accurate than information disconfirming each other's preferences. Finally, we hypothesize that group members who communicate information confirming each other's preferences receive positive feedback for doing so, which, in turn, leads group members to mention even more of this information. The results of 3 studies with pseudo and face-to-face interacting dyads provide converging support for our model. © 2014 American Psychological Association.

the individual preference effect supplements the predominant group-level explanations for the failure of groups to solve hidden profiles. Even in the absence of dysfunctional group-level processes, group members tend to stick to their suboptimal initial decision preferences due to preference-consistent evaluation of information. However, previous experiments demonstrating this effect retained two group-level processes, namely (a) social validation of information supporting the group members’ initial preferences and (b) presentation of the additional information in a discussion format. Therefore, it was unclear whether the individual preference effect depends on the co-occurrence of these group-level processes. Here, we report two experiments demonstrating that the individual preference effect is indeed an individual-level phenomenon. Moreover, by a comparison to real interacting groups, we can show that even when all relevant information is exchanged and when no coordination losses occur, almost half of all groups would fail to solve hidden profiles due to the individual preference effect.