Anthropomorphism in comparative affective science: Advocating a mindful approach.

Anthropomorphism is the attribution of human-like capacities and traits to non-human entities. Anthropomorphism is ubiquitous in everyday life and in scientific domains, operating both implicitly and explicitly as a function of the human lens through which we view the world. A rich history of work in psychology, animal behavior, cognitive science, and philosophy has highlighted the negative and, to a lesser degree, the positive implications of anthropomorphism. In this article, we aim to provide a nuanced perspective of how anthropomorphism impacts the work of comparative affective science. Specifically, we discuss three domains of empirical inquiry in which lessons can be drawn about the benefits and pitfalls of anthropomorphism: responses to death, inequity aversion, and prosocial behavior. On balance, we advocate a mindful approach to anthropomorphizing in comparative affective science, and comparative science more generally.

Urinary oxytocin in capuchin monkeys: Validation and the influence of social behavior.

In highly social species, like primates, oxytocin plays an important role in cooperation, and in the formation and maintenance of social relationships. Despite recent interest in the relationship between oxytocin and social behavior in nonhuman primates, relatively little is known about endogenous oxytocin in social New World Monkeys. In this paper, we investigate the relationship between oxytocin and affiliative behaviors in socially-housed captive capuchin monkeys (Sapajus [Cebus] apella) by first validating methods of analysis of urinary oxytocin in this species and, second, examining the effects of grooming and fur-rubbing behavior on oxytocin concentrations and further affiliative behavior. In the validation, we found that intranasal exogenous oxytocin significantly increased urinary oxytocin 15-60 min post-administration. Oxytocin was also implicated in both grooming and fur-rubbing behaviors. We found that oxytocin concentrations increased after subjects engaged in grooming or fur-rubbing. In addition, we found that fur-rubbing influenced affiliative behaviors, both during and after a social fur-rubbing bout. While individuals spent more time in contact and proximity while fur-rubbing, immediately following the fur-rubbing event (15-30 min afterwards) all affiliative behaviors decreased. This supports previous research that oxytocin may, in fact, initially be related to increased social distance in this species. Yet, an increase in all affiliative behaviors 30-45 min after the onset of fur-rubbing suggests that fur-rubbing, like grooming, may ultimately function to strengthen social relationships. Overall, these results support a critical role for oxytocin in affiliative behaviors that maintain and strengthen social relationships in capuchin monkeys, and highlight the complexity of the interactions among oxytocin, affiliative behaviors, and social bonding.

The neural basis of perceived unfairness in economic exchanges.

Human decision making in situations of inequity has long been regarded as a competition between the sense of fairness and self-interest, primarily based on behavioral and neuroimaging studies of inequity that disfavor the actor while favoring others. Here, we use functional magnetic resonance imaging experiments to study refusals and protests using both favoring and disfavoring inequity in three economic exchange games with undercompensating, nearly equal, and overcompensating offers. Refusals of undercompensating offers recruited a heightened activity in the right dorsolateral prefrontal cortex (dlPFC). Accepting of overcompensating offers recruited significantly higher node activity in, and network activity among, the caudate, the cingulate cortex, and the thalamus. Protesting of undercompensating fixed offers activated the network consisting of the right dlPFC and the left ventrolateral prefrontal cortex and midbrain in the substantia nigra. These findings suggest that perceived fairness and social decisions are the results of coordination between evaluated fairness norms, self-interest, and reward.