Predicting Prosociality in Primates: Socio-Ecological Influences and a Framework of Inter-Brain Neural Synchronization

In the past, prosociality has been considered a hallmark of humans; however, recently, accumulating data have empirically revealed that non-human animals also show prosocial behavior. In situations in which animals cannot predict return benefits, prosocial behavior is probably driven by other-regarding motivation. A sense of fairness and empathy continue to draw attention as the most plausible candidates for the psychological mechanisms underlying such prosocial behavior. In this article, we first introduce comparative studies on prosocial behavior in non-human primates and discuss similarities and differences between humans and non-human primates. Then, we discuss the role of a sense of fairness and empathy. In this paper, we hypothesize that empathy may promote prosocial behavior, whereas a sense of fairness may play a role as a stabilizer, but not as a promoter of prosocial behavior in non-human animals. We further hypothesize that prosocial behavior motivated by sympathetic concerns can survive only with a sense of fairness, the inhibitory system for unnecessarily excessive expression of prosocial behavior. Without a sense of fairness, empathic animals might be exploited by free-riders, which might lead to the extinction of cooperation. Therefore, the interplay of a sense of fairness and empathy are both important to maintaining prosocial behavior and cooperation. This hypothesis seems to be supported by comparative studies with non-human primates and also by neural studies with humans.

This study examined (a) the main and interactive effects of goal orientations and perceived motivational climate on prosocial and antisocial behaviour, and (b) whether number of seasons one has played for the team interacts with motivational climate in predicting prosocial and antisocial behaviour in association football. Participants were 325 male association football players, whose age ranged from 12 to 17 years. Athletes completed questionnaires measuring frequency of prosocial and antisocial behaviours in football, goal orientation, motivational climate and social desirability, and indicated the number of seasons they had played for their current team. Regression analyses revealed that task orientation and mastery climate were positive predictors of prosocial behaviour, whereas ego orientation and performance climate were positive predictors of antisocial behaviour. In addition, task orientation negatively predicted antisocial behaviour, while ego orientation negatively predicted prosocial behaviour. No significant interactions between task and ego orientation and mastery and performance motivational climate were found. Finally, mastery climate negatively predicted antisocial behaviour for those who had played many seasons for the team. In conclusion, strengthening task orientation and mastery climate and weakening ego orientation may enhance prosocial behaviour. However, for antisocial conduct to be eliminated from the context of association football, ego orientation and performance climate need to be tempered, as these constructs exert unique independent effects on antisocial behaviour.

The purpose of this study is to investigate the correlations and influences of psychopathy, quality of father-child relationship, father’s authoritative parenting styles and family adversity on prosocial and problematic behaviours in Singapore. A secondary objective of this study is to look the moderation relationship of the quality of father-child relationship (i.e. father’s support and admiration dimension and father’s conflict and criticism dimension) with the focus variables in this study. A review of the literature indicates that psychopathy, quality of father-child relationship, father’s authoritative parenting styles and family adversity are predictors of prosocial and problematic behaviours. Current research on child and adolescent behaviours tends to emphasize either prosocial or problematic behaviours, but seldom are both kinds of behaviours investigated in a single study and non-clinical sample. To fill this research gap, the present study investigates both the prosocial and antisocial behaviours, as well as, the factors influencing the behaviours in one single study with a non-clinical sample. Data was collected from 694 adolescent participants. Analyses was carried out to establish the variables associated with prosocial and problematic behaviours and their correlations between the variables. Moderation relationships were explored for father’s support and admiration dimension and conflict and criticism dimension as moderators for the independent variables on prosocial and problematic behaviours. Results from this study supported previous research findings that found psychopathy, quality of father-child relationship, father’s authoritative parenting styles and family adversity to be significantly associated with prosocial and problematic behaviours. In this study, psychopathy and father’s authoritative parenting style predicted prosocial and problematic behaviours. Also, family adversity was found to predict problematic behaviours during adolescence but no significant relationship was found between family adversity and prosocial behaviours. The key findings from our moderation analysis reported that for dispositional trait-like individual characteristics, like psychopathy, father’s support and admiration dimension plays a role in decreasing problematic behaviour. For contextual situations type of variables that involved reciprocal relationships or interactions (e.g., authoritative parenting and adverse family circumstances), father’s conflict and criticism dimension plays a moderating role in influencing problematic behaviours.

BackgroundDimensional models of personality disorders postulate interpersonal dysfunction as the core feature of personality pathology, and describe maladaptive personality traits that characterize the specific pattern of dysfunction that is experienced. Herein, we examined whether maladaptive traits predict prosocial and trusting behavior, both of which are highly relevant behaviors for interpersonal functioning. Specifically, we examined antagonism as a predictor of prosocial behavior in a dictator game, and suspiciousness as a predictor of trust in the faith game.Materials and methodsThe study was preregistered and conducted online. The preregistration protocol is available at https://osf.io/er43j. Data and code are available at https://osf.io/2rvbg/. Participants (N = 445) completed the German version of the Personality Inventory for DSM-5 to measure antagonism and suspiciousness. Additionally, they played the dictator game (more money taken away from another person indicates less prosocial behavior) and the faith game (choosing the sure choice instead of the faith choice indicates less trust). We conducted a linear regression model to test whether antagonism is associated with prosocial behavior in the dictator game and a logistic regression model to test whether suspiciousness predicts selection of the sure choice in the faith game.ResultsAs hypothesized, higher levels of antagonism were associated with less prosocial behavior in the dictator game. The remaining hypotheses were not supported, as suspiciousness was not significantly associated with the likelihood of choosing the sure choice in the faith game. Exploratory analyses on participants’ estimates of the sure choice amount suggest successful experimental manipulation in the faith game.ConclusionsThe results on antagonism and prosocial behavior are consistent with those of previous studies that used categorial classification systems of personality disorders or examined non-pathological personality traits. Potential explanations for the non-significant effects of suspiciousness are discussed, including the small size and range of the sure choice payoff and that the anonymity of the game may have precluded suspicious traits from expressing. Future research with higher stakes and known interaction partners is needed to further probe the effects of suspiciousness.

Many nonhuman primates live in proximity to humans, and all studied primate populations are influenced in some ways by human interaction. While the effects of human interference on primate behavior and ecology are an important area of research in contemporary primatology, to date there is no systematic way to report the types or level of anthropogenic influence for a primate study population. In this paper, I introduce a diagnostic classification system that will allow primate field researchers to clearly and consistently report anthropogenic conditions at their study sites. This system provides a way to identify population conditions for four major variables: landscape, human-nonhuman primate interface, diet, and predation risk. The incredible diversity of the Order Primates necessitates a descriptive system that is applicable across a wide range of habitat types, social groupings, and ecological roles, so the proposed classification system has been specifically designed to avoid quantitative ranking. Instead, the system is intended to provide a standardized way to report a wealth of population and site information in a simple format. This will allow for meta-analysis of specific conditions across study sites, leading to a greater understanding of the effects of different forms of anthropogenic influence on primate behavior and ecology.

Grounded in Basic Psychological Need Theory, we examined the direct effects of the satisfaction of three basic psychological needs at school (i.e., satisfaction of autonomy needs at school, satisfaction of relatedness needs at school, and satisfaction of competence needs at school) on prosocial behavior and antisocial behavior as well as the mediation effects of school satisfaction on the relations between the satisfaction of three basic psychological needs at school and prosocial behavior as well as antisocial behavior. We employed a sample of 801 Chinese children (429 males; Mage = 9.47) in a three-wave longitudinal study, with each wave occurring 6 months apart. Direct and indirect effects were estimated by Structural Equation Modeling. Results indicated that: (1) Satisfaction of relatedness needs at school and competence needs at school, but not satisfaction of autonomy needs at school, displayed direct effects on prosocial behavior. Also, satisfaction of relatedness needs at school, but not satisfaction of autonomy needs at school or competence needs at school, displayed direct effects on antisocial behavior. (2) Both satisfaction of relatedness needs at school and competence needs at school displayed indirect effects on prosocial behavior and antisocial behavior via school satisfaction as a mediator. However, satisfaction of autonomy needs at school failed to have indirect effects on prosocial behavior or antisocial behavior via school satisfaction. These findings suggest differential predictors of children’s prosocial and antisocial behavior, supporting the separability of the two constructs. The findings also suggest developmental differences in need satisfaction, with the satisfaction of autonomy needs playing a relatively less important role in school-age children. We also discussed limitations and practical applications of the study.

Exploring sibling prosocial and aggressive behavior in young people exposed and not exposed to intimate partner violence.

This study examined the behavioral, personality, and communicative predictors of acceptance and popularity in 608 early adolescents. Data were collected with sociometric methods and ratings in 30 sixth-grade classrooms. Hierarchical regressions were run to predict acceptance and popularity from prosocial, antisocial, and withdrawn behavior, agreeableness and extraversion, and pragmatic communicative skills. Low levels of antisocial behavior positively predicted peer acceptance. Popularity depended on a more complex profile of predictors. Prosocial and antisocial behavior contributed positively to popularity, whereas withdrawn behavior contributed negatively. Extraversion and pragmatic skills also played a role in the prediction of popularity. Extraversion moderated the associations of prosocial and antisocial behavior with popularity. Popularity was highest when high levels of prosocial or antisocial behavior were combined with high levels of extraversion. Pragmatic skills moderated the association of prosocial behavior with popularity. Popularity was highest when prosocial behavior and pragmatic skills were high.

We use longitudinal multilevel modeling to test how exposure to community violence and cognitive and behavioral factors contribute to the development of aggressive and prosocial behaviors. Specifically, we examine predictors of self-, peer-, and teacher-reported aggressive and prosocial behavior among 266 urban, African American early adolescents. We examine lagged, within-person, between-person, and protective effects across 2 years. In general, results suggest that higher levels of violence exposure and aggressive beliefs are associated with more aggressive and less prosocial peer-reported behavior, whereas greater self-efficacy to resolve conflict peacefully is associated with less aggression across reporters and more teacher-reported prosocial behavior. Greater knowledge and violence prevention skills are associated with fewer aggressive and more prosocial teacher-reported behaviors. Results also suggest that greater self-efficacy and lower impulsivity have protective effects for youth reporting higher levels of exposure to community violence, in terms of teacher-reported aggressive behavior and peer-reported prosocial behavior. Differences among reporters and models are discussed, as well as implications for intervention.

New Models and Insights into Primate Evolutionary Morphology

Previous preclinical studies have demonstrated that 3,4-methylenedioxymethamphetamine (MDMA) dose-dependently increases pro-social behavior and affiliative vocalizations in male nonhuman primates. As diagnostic criteria for several psychiatric diseases includes deficits in social functioning, examining the conditions under which MDMA selectively increases pro-social behavior may provide important insights into MDMA's potential as a therapeutic. One such condition is whether a subject's drug history has any impact on MDMA's ability to modulate social behavior. Here, we examined the ability of MDMA and d-methamphetamine (MA) to modulate pro-social behavior and affiliative vocalizations in four pairs of drug-naïve female squirrel monkeys (n=8). Doses of MDMA (0.1-1.0 mg/kg), MA (0.03-0.3 mg/kg) or saline vehicle were administered 10-min prior to observation sessions in which pro-social behavior (huddling, touching, and sitting within proximity to each other) was scored by a blind observer. Vocalizations were recorded and spectrograph analyses were used to characterize vocalizations as either affiliative or aggressive. Results show that MDMA dose-dependently increased pro-social behavior, with 1.0 mg/kg eliciting the highest pro-social scores in comparison to saline, whereas the dopamine-preferring releaser MA elicited little pro-social behavior in comparison to saline. In contrast, both MDMA and MA dose-dependently decreased all measures of vocalizations in females, with the highest total number of vocalizations evident after 0.1 mg/kg MDMA and the lowest total number of vocalizations evident at 1.0 mg/kg MDMA. Aggressive vocalizations were not elicited by either MDMA or MA. These results corroborate previous findings that MDMA, but not d-MA, increases pro-social behavior in male subjects and extends them to females. However, MDMA's increase in pro-social behavior appears to be de-coupled from vocalizations in drug-naïve female subjects. These data are in contrast to other reports in male subjects with drug histories showing that MDMA dose-dependently increases affiliative behavior and vocalizations. Taken together, these results suggest that sex and drug-history may be important variables in considering MDMA's efficacy in increasing pro-social behavior. Future studies will include drug naïve male subjects to investigate sex as a biological variable as well as other drugs that vary in selectivity for dopamine or serotonin release.

ObjectiveIn this study, empathy is quantified using a novel social test. Empathy and prosocial behavior are linked to the expression of oxytocin in humans and rodent models. Specifically, prosocial behavior in prairie voles (Microtus ochrogaster) has been linked to the expression of oxytocin in the paraventricular nucleus of the hypothalamus. The animal’s behavior was considered empathic if it spends significantly more time attempting to remove a loos fitting restraint (tether) from the stimulus animal than time in contact with a, simultaneously presented, non-social object similar to the tether. The behavioral data was cross-referenced with the number of neurons expressing oxytocin and arginine vasopressin, as well as the density of dopaminergic neurons (identified by the expression of tyrosine hydroxylase), in the paraventricular nucleus of the hypothalamus. These proteins influence empathic behavior in humans, non-human primates, rats, mice, and prairie voles.ResultsThe consistency between neuroanatomical mechanisms linked to empathy, and the durations of time spent engaging in empathic contact, support the prediction that the empathic contact in this test is a distinct prosocial behavior, lacking prior behavioral training or the naturally occurring ethological relevance of other prosocial behaviors, and is a measure of empathy.

The purpose of this study was to examine task-, ego-, and social-goal orientations as predictors of prosocial and antisocial behavior in youth soccer. Participants were 365 male (n = 227) and female (n = 138) youth soccer players Mage = 13.4 years, SD = 1.8), who completed questionnaires measuring task and ego orientation; the goals of social affiliation, social recognition and social status; prosocial and antisocial behavior; and demographics. Regression analyses revealed that prosocial behavior was predicted positively by task orientation and social affiliation and negatively by social status. In contrast, antisocial behavior was predicted positively by ego orientation and social status and negatively by task orientation. Findings for task and ego orientation are consistent with previous work. Social-goal orientations explained further variance in prosocial and antisocial behavior, and their inclusion in future moral research is encouraged.

Based on the human ecological model, this study hypothesized that individual competence in empathy, prosocial moral reasoning, and social influence from parents, peers, and school are the key determinants of prosocial behavior among Chinese adolescents in Hong Kong. We recruited a sample of high school students who engaged in volunteering activities regularly (N = 580). They completed a self-administrated questionnaire designed to measure prosocial behavior and its hypothesized predictors using a number of standardized instruments. The results of multiple regression show that social influence factors, including peer, school, and parent influence, are strong predictors of helping intention and prosocial behavior, while individual competence factors like empathy and prosocial moral reasoning are not. Male participants had higher empathy scores and helping intention than females, perceived their parents as more helpful, and their schools as more supportive of prosocial behavior. However, the significant predictors of prosocial behavior and helping intention were similar across gender. The findings indicate that social influence is strongly linked to prosocial behavior. This implies that socialization and social support for prosocial norms and behavior can exert a powerful influence on the behavior of young people in a Chinese population.

Any attempt at understanding human homosexuality must also include a thorough analysis of same-sex sexual behaviour in the other primates. It is this comparative approach that can uncover those aspects that are common to all or some primates and those that are unique to any particular species. The theory of evolution predicts similarities of traits among closely related taxa due to common descent; it also predicts the possibility of evolutionary convergence among not so closely related taxa if their evolutionary history has unfolded under similar environmental conditions. A further prediction concerns divergences in traits, including behaviour, due to phylogenetic effects, drift and adaptive responses to diverse environmental, including social, circumstances. In this chapter I firstly consider homosexual behaviour as it applies to the non-human primates. This comparative approach may help us to better understand those aspects of human homosexuality that are unique and those that are shared with our closest living relatives. With these thoughts in mind, I start with an introduction to primate diversity and evolution. Primate diversity and evolution More than 300 extant species of primate have been described; the precise numbers depend upon the propensity to either ‘split’ or ‘lump’ taxa in various classification schemes. All these species, however, may be assigned to one of six major groupings or superfamilies of the Order Primates: the lemurs of Madagascar (Lemuroidea), the galagos and lorises of Africa and Asia (Lorisoidea), the tarsiers of SE Asia (Tarsioidea), New World monkeys (Ceboidea), Old World monkeys (Cercopithecoidea) and the apes and humans (Hominoidea). Phylogenetic relationships between these six superfamilies are shown diagrammatically in Figure 9.1. George Gaylord Simpson (1945) divided the Order Primates into two suborders: the Prosimii (lemurs, lorises, galagos and tarsiers) and the Anthropoidea (monkeys, apes and humans).