Are older adults less generous? Age differences in emotion-related social decision making.

In social interaction, age-related differences in emotional processing may lead to varied social decision making between young and older adults. However, previous studies of social decision making have paid less attention to the interactants' emotions, leaving age differences and underlying neural mechanisms unexplored. To address this gap, the present study combined functional and structural magnetic resonance imaging, employing a modified dictator game task with recipients displaying either neutral or sad facial expressions. Behavioral results indicated that although older adults' overall allocations did not differ significantly from those of young adults, older adults' allocations showing a decrease in emotion-related generosity compared to young adults. Using representational similarity analysis, we found that older adults showed reduced neural representations of recipients' emotions and gray matter volume in the right anterior cingulate gyrus (ACC), right insula, and left dorsomedial prefrontal cortex (DMPFC) compared to young adults. More importantly, mediation analyses indicated that age influenced allocations not only through serial mediation of neural representations of the right insula and left DMPFC, but also through serial mediation of the mean gray matter volume of the right ACC and left DMPFC. This study identifies the potential neural pathways through which age affects emotion-related social decision making, advancing our understanding of older adults' social interaction behavior that they may not be less generous unless confronted with individuals with specific emotions.

Prosocial option increases women's entry into competition.

We provide evidence that women enter competitions at the same rate as men when the incentive for winning includes the option to share part of the rewards with the losers (i.e., when the incentive system is socially oriented). Using an experiment (with N = 238 subjects from three laboratories), we find that about 16% more men than women choose to compete in the standard tournament; this gender gap is eliminated in the socially oriented incentive treatment. While men's choice to compete remains unchanged, at around 52% in both conditions, women increase their entry rate from 35% in the standard tournament to 60% when the incentive includes a socially oriented option.

The Medusa effect reveals levels of mind perception in pictures.

Throughout our species history, humans have created pictures. The resulting picture record reveals an overwhelming preference for depicting things with minds. This preference suggests that pictures capture something of the mind that is significant to us, albeit at reduced potency. Here, we show that abstraction dims the perceived mind, even within the same picture. In a series of experiments, people were perceived as more real, and higher in both Agency (ability to do) and Experience (ability to feel), when they were presented as pictures than when they were presented as pictures of pictures. This pattern persisted across different tasks and even when comparators were matched for identity and image size. Viewers spontaneously discriminated between different levels of abstraction during eye tracking and were less willing to share money with a more abstracted person in a dictator game. Given that mind perception underpins moral judgement, our findings suggest that depicted persons will receive greater or lesser ethical consideration, depending on the level of abstraction.

Typical diet and type of economy do not predict food-sharing behaviors in three Tanzanian societies.

Food sharing behavior is a widely observed phenomenon, and it draws attention of scholars interested in finding both proximate and ultimate explanations of such practices. In the current study, we focused on possible socio-economic and environmental food-sharing predictors: type of economy (i.e., immediate-return vs. delayed-return) and typical diet composition (i.e., proportion of proteins and carbohydrates in typical daily caloric intake). We investigated whether members of three societies from Tanzania (N = 177), namely hunter-gatherers (Hadza), pastoralists (Datoga), and agriculturalists (Iraqw) differ with regard to food-sharing patterns in the Dictator Game and reactions to violations of the food-sharing norms in the Ultimatum Game. We found that neither the type of economy nor the typical diet influenced our outcomes. The results indicated, however, that food sharing behavior was positively predicted by certain individual-level characteristics: people of higher strength and lower body fat shared more food, and women were more willing to share food than men.

Role of anterior midcingulate cortex in self-reward representation and reward allocation judgments within social context.

Evaluating rewards for the self and others is essential for social interactions. Previous research has probed the neural substrates signaling rewards in social decision-making tasks as well as the differentiation between self- and other-reward representations. However, studies with different designs have yielded mixed results. After analyzing and comparing previous designs, we differentiated three components in this study: task (reward representation vs. social judgment of reward allocation), agency (self vs. other), and social context (without vs. within). Participants were asked to imagine various share sizes as a proposer in a dictator game during fMRI, and then rated their willingness and preference for these offers in a post-scan behavioral task. To differentiate the regions involved in processing rewards without and within context, we presented the reward to each agent in two sequential frames. Parametric analyses showed that, in the second frame (i.e., within social context), the anterior midcingulate cortex (aMCC) signaled self-reward and preferences for the offer, whereas the right insula tracked the likelihood of proposing the offer. Belief in a just world is positively associated with aMCC responses to self-reward. These results shed light on the role of the aMCC in coding self-reward within the social context to guide social behaviors.

Preschoolers agree to and enforce prosocial, but not selfish, sharing norms.

Young children act prosocially in many contexts but are somewhat selfish when it comes to sharing their resources in individual decision-making situations (e.g., the dictator game). But when deciding collectively, would they make it a binding rule for themselves and others to act selfishly in a resource sharing context? Here we used a novel "group dictator game" in a norm creation paradigm to investigate whether 3- and 5-year-olds (N = 48) would agree to and enforce a selfish or prosocial sharing norm. Children from a Western cultural background were paired with two puppets at a time. Each group member had an endowment of four stickers and faced a photograph of a recipient. In the prosocial norm condition a proposer puppet suggested to share half of one's endowment, whereas in the selfish norm condition another proposer suggested to share nothing. The protagonist puppet then either followed or violated the suggested norm. We found that 5-year-olds (but not 3-year-olds) rejected selfish proposals more often than prosocial proposals. Importantly, older (but not younger) preschoolers also enforced the prosocial (but not the selfish) norm by protesting normatively and intervening when the protagonist acted selfishly (and thus violated the norm). These results indicate that a collective decision-making context may enhance preschoolers' prosociality and that moral considerations on the content of a proposed sharing rule influence preschoolers' creation and enforcement of such nonarbitrary norms.

The animals in moral tales: Does character realism influence children's prosocial response to stories?

Previous research has suggested that moral stories depicting realistic characters may better facilitate children's prosocial behavior than those containing anthropomorphized animal characters. The current study is a conceptual replication with a different sample and an extended age range. We examined the relationships among story character realism (anthropomorphized animal or human), theme (sharing or busyness), age, and prosocial behavior (i.e., resource allocation). Four versions of an illustrated storybook were created: an Animal Sharing book, an Animal Busy book, a Human Sharing book, and a Human Busy book. A total of 179 children aged 3-7 years listened to one of the four versions of the story. Children's sticker donating behavior was measured prior to hearing the story and again following a story recall task. All groups donated more stickers post-story than pre-story. Younger children were more likely to increase their donation than older children, and children who had made higher human internal state attributions in a previous experimental session donated more stickers post-story. In contrast to previous research, we found that a sharing-themed narrative depicting human characters was no more influential for sticker donation than the other stories.

Communication in context: Interpreting promises in an experiment on competition and trust.

How much do people lie, and how much do people trust communication when lying is possible? An important step toward answering these questions is understanding how communication is interpreted. This paper establishes in a canonical experiment that competition can alter the shared communication code: the commonly understood meaning of messages. We study a sender-receiver game in which the sender dictates how to share $10 with the receiver, if the receiver participates. The receiver has an outside option and decides whether to participate after receiving a nonbinding offer from the sender. Competition for play between senders leads to higher offers but has no effect on actual transfers, expected transfers, or receivers' willingness to play. The higher offers signal that sharing will be equitable without the expectation that they should be followed literally: Under competition "6 is the new 5."

Oxytocin amplifies the influence of good intentions on social judgments.

Studies have shown that the evolutionarily conserved neuropeptide oxytocin (OT) promotes various prosocial behaviors, yet there are few studies of the effect of OT on social judgments, especially on judgments when the actor's intention and the final outcome are incongruent. In a double-blind, placebo-controlled experiment, participants were asked to play the role of the recipient in a dictator game and to make social judgments about the dictator after intranasal OT administration. To isolate the outcome and the intention of the dictator's allocation, we developed a novel social judgment task in which recipients were told that 50% of the dictators' proposals would be reversed. The results showed that the effect of OT on social judgment was modulated by intention: OT increased goodness ratings only towards dictators with hyperfair intention. Our findings support the affiliative-motivation theory which states that OT enhances the affiliative motivation and recognition of positive-valence social stimuli.

The development of social comparisons and sharing behavior across 12 countries.

Humans are social beings, and acts of prosocial behavior may be influenced by social comparisons. To study the development of prosociality and the impact of social comparisons on sharing, we conducted experiments with nearly 2500 children aged 3-12 years across 12 countries across five continents. Children participated in a dictator game where they had the opportunity to share up to 10 of their stickers with another anonymous child. Then, children were randomized to one of two treatments. In the "shared a little" treatment children were told that another child from their school had shared 1 sticker, whereas in the "shared a lot" treatment children were told that another child from their school had shared 6 stickers in the same game. There was a strong increase in baseline sharing with age in all countries and in both treatments. The "shared a lot" treatment had a positive treatment effect in increasing sharing overall, which varied across countries. However, cross-cultural comparisons did not yield expected significant differences between collectivist and individualist countries. Our results provide interesting evidence for the development of sharing behavior by age across the world and show that social information about the sharing of peers is important for children's decision making.

Behavioral and electrophysiological responses to fairness norm violations in antisocial offenders.

Antisocial personality disorder is characterized by a stable, lifelong pattern of disregard for and violation of others' rights. Disruptions in the representation of fairness norms may represent a key mechanism in the development and maintenance of this disorder. Here, we investigated fairness norm considerations and reactions to their violations. To examine electrophysiological correlates, we assessed the medial frontal negativity (MFN), an event-related potential previously linked to violations of social expectancy and norms. Incarcerated antisocial violent offenders (AVOs, n = 25) and healthy controls (CTLs, n = 24) acted as proposers in the dictator game (DG) and ultimatum game (UG) and received fair vs. unfair UG offers from either another human (social context) or a computer (non-social context). Results showed that AVOs made lower offers in the DG but not the UG, indicating more rational and strategic behavior. Most importantly, when acting as recipients in the UG, acceptance rates were modulated by social context in CTLs, while AVOs generally accepted more offers. Correspondingly, ERP data indicated pronounced MFN amplitudes following human offers in CTLs, whereas MFN amplitudes in AVOs were generally reduced. The current data suggest intact fairness norm representations but altered reactions to their violation in antisocial personality disorder.

Prosocial behavior in aging: which factors can explain age-related differences in social-economic decision making?

OBJECTIVES: Older adults tend to exhibit more prosocial behavior than younger adults. However, little research has focused on understanding the factors that may explain such differences in the social decision-making process. The first aim was to examine if, and to what degree, the content of social information about a recipient has an impact on young vs. older adults' prosocial behavior. The second aim was to understand if empathic concern, Theory of Mind, and reasoning explain the (expected) age differences in prosociality. DESIGN: Cross-sectional study. SETTING: The study was conducted in northern Italy in a laboratory setting. PARTICIPANTS: Forty-eight younger adults (Mage = 23.29; SD = 2.20) and 48 older adults (Mage = 70.19; SD = 5.13). MEASUREMENTS: Prosocial behavior was measured using the Dictator Game in which participants split a sum of money with recipients presented with four levels of description: no information, physical description, positive psychological description, and negative psychological description. In addition, participants performed tasks on emphatic concern, Theory of Mind, and reasoning. RESULTS: Results showed that older adults are more prosocial than younger adults in the Dictator Game. This finding was evident when the recipient was described with positive psychological and physical features. This pattern of results was statistically explained by the reduction in reasoning ability. CONCLUSION: These findings suggest a relationship between age-related reduction in reasoning ability and older adults' prosocial behavior. The theoretical and practical implication of the empirical findings are discussed.

Feel good, do good? Subjective well-being and sharing behavior among children.

The current study examined the association between children's subjective well-being (SWB) and their sharing behavior. School children (second and fifth graders) were interviewed in private and had an opportunity to share candy with a recipient under one of two between-participants conditions: Perceived-High Obligation (a recipient in poverty) and Perceived-Low Obligation (a temporarily needy recipient). Results provide initial evidence of an increased association between SWB and sharing decisions with age; whereas SWB was not significantly correlated with the incidence of sharing by younger children (second graders), it was a positive predictor of sharing behavior among fifth graders. Manipulating the perceived obligation to share (by emphasizing the causes beyond the recipient's need), we found that higher levels of SWB were linked to sharing only in the Perceived-Low Obligation condition. Children with lower SWB behaved as expected by the norm and shared to a similar degree as children with higher SWB when sharing felt obligatory. However, when sharing was less obligatory, higher levels of SWB were linked to higher levels of sharing.

Cortical thickness of the dorsolateral prefrontal cortex predicts strategic choices in economic games.

Human prosociality has been traditionally explained in the social sciences in terms of internalized social norms. Recent neuroscientific studies extended this traditional view of human prosociality by providing evidence that prosocial choices in economic games require cognitive control of the impulsive pursuit of self-interest. However, this view is challenged by an intuitive prosociality view emphasizing the spontaneous and heuristic basis of prosocial choices in economic games. We assessed the brain structure of 411 players of an ultimatum game (UG) and a dictator game (DG) and measured the strategic reasoning ability of 386. According to the reflective norm-enforcement view of prosociality, only those capable of strategically controlling their selfish impulses give a fair share in the UG, but cognitive control capability should not affect behavior in the DG. Conversely, we support the intuitive prosociality view by showing for the first time, to our knowledge, that strategic reasoning and cortical thickness of the dorsolateral prefrontal cortex were not related to giving in the UG but were negatively related to giving in the DG. This implies that the uncontrolled choice in the DG is prosocial rather than selfish, and those who have a thicker dorsolateral prefrontal cortex and are capable of strategic reasoning (goal-directed use of the theory of mind) control this intuitive drive for prosociality as a means to maximize reward when there are no future implications of choices.

Friend versus foe: Neural correlates of prosocial decisions for liked and disliked peers.

Although the majority of our social interactions are with people we know, few studies have investigated the neural correlates of sharing valuable resources with familiar others. Using an ecologically valid research paradigm, this functional magnetic resonance imaging study examined the neural correlates of prosocial and selfish behavior in interactions with real-life friends and disliked peers in young adults. Participants (N = 27) distributed coins between themselves and another person, where they could make selfish choices that maximized their own gains or prosocial choices that maximized outcomes of the other. Participants were more prosocial toward friends and more selfish toward disliked peers. Individual prosociality levels toward friends were associated negatively with supplementary motor area and anterior insula activity. Further preliminary analyses showed that prosocial decisions involving friends were associated with heightened activity in the bilateral posterior temporoparietal junction, and selfish decisions involving disliked peers were associated with heightened superior temporal sulcus activity, which are brain regions consistently shown to be involved in mentalizing and perspective taking in prior studies. Further, activation of the putamen was observed during prosocial choices involving friends and selfish choices involving disliked peers. These findings provide insights into the modulation of neural processes that underlie prosocial behavior as a function of a positive or negative relationship with the interaction partner.

The interplay between sharing behavior and beliefs about others in children during dictator games.

Previous studies in adults demonstrated that beliefs and sharing decisions in social scenarios are closely related. However, to date, little is known about the development of this relationship in children. By using a modified dictator game, we assessed sharing behavior and beliefs about others in children between 3 and 12 years old. We performed four studies (N = 376) aimed to assess whether decisions were related to beliefs (Studies 1 and 2) and whether information about the recipient's forced sharing behavior would shape decisions and beliefs (Studies 3 and 4). Results of Studies 1 and 2 showed that beliefs about others' generosity were related to children's sharing behavior. In Studies 3 and 4, we found that only children older than 9 years shared more pieces of candy when they knew that the recipient would be forced to share (cooperative context) than when they knew that the recipient would be forced not to share (noncooperative context). Besides, children older than 6 years did not modify their beliefs about others' generosity according to these social contexts. These results suggest that normative or preconceived beliefs about the functioning of the social world may guide social behavior in children.

Giving behavior of millionaires.

This paper studies conditions influencing the generosity of wealthy people. We conduct incentivized experiments with individuals who have at least €1 million in their bank account. The results show that millionaires are more generous toward low-income individuals in a giving situation when the other participant has no power, than in a strategic setting, where the other participant can punish unfair behavior. Moreover, the level of giving by millionaires is higher than in any other previous study. Our findings have important implications for charities and financial institutions that deal with wealthy individuals.

Evidence for a relationship between trait gratitude and prosocial behaviour.

Prosocial behaviour towards unrelated others is communally beneficial but can be individually costly. The emotion of gratitude mitigates this cost by encouraging direct as well as "upstream" reciprocity, thereby facilitating cooperation. A widely used method for measuring trait gratitude is the Gratitude Questionnaire (GQ6) [McCullough, M., Emmons, R., & Tsang, J. (2002). The grateful disposition: A conceptual and empirical topography. Journal of Personality and Social Psychology, 82, 112-127. Retrieved from https://doi.org/10.1037/0022-3514.82.1.112 ]. Here we undertake an assessment of the external validity of the GQ6 by examining its relationship with two incentivized economic games that serve as face valid indices of generosity and reciprocity. In two studies (total N = 501) we find that trait gratitude as measured by the GQ6 predicts greater donations in a charity donation task as well as greater transfers and returns in an incentivized trust game. These results support the hypothesis that individuals with higher trait gratitude are more generous and trusting on average, and provide initial evidence as to the predictive validity of the GQ6.

What do we expect from a beauty? Facial attractiveness of the opposite sex gives rise to discrepancies in males' anticipation and demand.

Facial attractiveness plays a significant role in social interactions and the effect of beauty premium is frequently observed. Previous studies showed that observing attractive counterparts would alleviate one's sense of unfairness. However, the mechanism underlying this phenomenon remained to be clarified. In this study, male participants were engaged in a modified Dictator game as recipients and their electroencephalograms were recorded. They were convinced that anonymous females who vary in facial attractiveness played as dictators. An outcome anticipation stage was implemented before proposed offers were presented and we focused on the cognitive process of subjective anticipation. A less negative Stimulus-preceding negativity was observed in the attractive face condition, suggesting that subjects paid less anticipatory attention toward proposed offers, and subjective expectation toward fair ones was weakened when beauties played as dictators. Thus, this study provides additional neural evidences for the beauty premium effect and suggests a reasonable explanation for this commonly reported phenomenon.

Influence of biases in numerical magnitude allocation on human prosocial decision making.

Over the past decade neuroscientific research has attempted to probe the neurobiological underpinnings of human prosocial decision making. Such research has almost ubiquitously employed tasks such as the dictator game or similar variations (i.e., ultimatum game). Considering the explicit numerical nature of such tasks, it is surprising that the influence of numerical cognition on decision making during task performance remains unknown. While performing these tasks, participants typically tend to anchor on a 50:50 split that necessitates an explicit numerical judgement (i.e., number-pair bisection). Accordingly, we hypothesize that the decision-making process during the dictator game recruits overlapping cognitive processes to those known to be engaged during number-pair bisection. We observed that biases in numerical magnitude allocation correlated with the formulation of decisions during the dictator game. That is, intrinsic biases toward smaller numerical magnitudes were associated with the formulation of less favorable decisions, whereas biases toward larger magnitudes were associated with more favorable choices. We proceeded to corroborate this relationship by subliminally and systematically inducing biases in numerical magnitude toward either higher or lower numbers using a visuo-vestibular stimulation paradigm. Such subliminal alterations in numerical magnitude allocation led to proportional and corresponding changes to an individual's decision making during the dictator game. Critically, no relationship was observed between neither intrinsic nor induced biases in numerical magnitude on decision making when assessed using a nonnumerical-based prosocial questionnaire. Our findings demonstrate numerical influences on decisions formulated during the dictator game and highlight the necessity to control for confounds associated with numerical cognition in human decision-making paradigms.NEW & NOTEWORTHY We demonstrate that intrinsic biases in numerical magnitude can directly predict the amount of money donated by an individual to an anonymous stranger during the dictator game. Furthermore, subliminally inducing perceptual biases in numerical-magnitude allocation can actively drive prosocial choices in the corresponding direction. Our findings provide evidence for numerical influences on decision making during performance of the dictator game. Accordingly, without the implementation of an adequate control for numerical influences, the dictator game and other tasks with an inherent numerical component (i.e., ultimatum game) should be employed with caution in the assessment of human behavior.