Biology subjects

Pfluger, L. S.

Publications and source records attributed to Pfluger, L. S..

3 recordsLinked to original sources

bioRxiv2025

Despotism promotes cooperation through enhanced interdependencies in non-human primate societies

The evolutionary mechanisms of cooperation are well-studied, yet what motivates individuals to cooperate remains unclear. Although conventionally associated with enhanced social tolerance (self-domestication hypothesis) and prosociality (cooperative-breeding hypothesis), individuals belonging to species that are neither self-domesticated nor cooperatively-breeding also cooperate. An overarching interdependency hypothesis posits that inter-individual dependencies promote cooperation, but comparative evidence is lacking. We experimentally studied cooperation, prosociality, and tolerance in six macaque species along a despotic-egalitarian gradient. Within-group cooperation was higher in despotic than egalitarian societies yet restricted to few partners. Prosociality, kinship, and tolerance positively predicted cooperation success. Agent-based models consistently showed that despotic societies have fewer but more stable social bonds and, thus, higher interdependencies than egalitarian ones. Our results suggest that interdependencies facilitate the emergence and maintenance of cooperation.

animal behavior and cognition↗

bioRxiv2023

Behavioural, physiological, and genetic drivers of coping

Animals regularly experience stressful situations, ranging from predation to social stress, yet successfully deal with them on most occasions. This adaptive mechanism, coping, reduces the adverse effects of stressors through behavioural and physiological efforts, failing to which may result in reduced fitness. However, considerable variation in coping is observed. Unlike in humans, coping is often considered a personality trait in non-human animals due to construct similarity, resulting in conceptual ambiguity. Besides, limited multidisciplinary research has rendered comprehending the drivers of coping in animals challenging. We assessed repetitive behavioural coping or coping styles (n=30), emotional arousal (n=12), and consistent inter-individual differences, i.e., personalities (n=32) of long-tailed macaques (Macaca fascicularis) using observations, ecologically relevant experiments, and infrared thermography. We finally investigated the association of coping with a Valine/Methionine polymorphism encoded by the Catechol-O-methyltransferase (COMT) gene (n=26), which is widely known for its involvement in human stress regulation. Our findings suggest that personality and the presence of the human equivalent COMT Val158Met polymorphism in long-tailed macaques are associated with emotion-focused and problem-focused coping styles. These coping styles were consistent with emotional arousal as measured with infrared thermography. We discuss these proximate drivers of coping for a better understanding of its evolution in primates.

animal behavior and cognition↗

bioRxiv2022

Prosociality in a despotic society

Humans possess remarkable prosocial tendencies beyond the confinement of kinship, which may be instrumental in promoting cooperative interactions and sociality at large. Yet, prosociality is an evolutionary conundrum as it does not provide immediate benefits to the actor. The domestication and cooperative-breeding hypotheses postulated that enhanced social tolerance and inter-individual dependence could nonetheless facilitate the evolution of prosociality. However, inconsistent results due to varying experimental paradigms, and restricted focus of research on tolerant and cooperatively breeding species, have impeded our understanding so far. Albeit counterintuitively, despotic societies with relatively low social tolerance levels represent an excellent opportunity to investigate prosociality due to their kin favoritism and potential interdependence among individuals in terms of social support. Japanese macaques (Macaca fuscata) live in strictly hierarchical matrilineal societies, where kin members have strong social bonds. Additionally, support from non-kins can be crucial to form coalitions and rank up in the hierarchy. Using a group-service paradigm, we tested prosociality in a semi-free-ranging group of Japanese macaques. In contrast to currently existing evidence, we found that individuals (n=25) can act prosocially and at comparably high rates as cooperative breeding- or self-domesticated species. The macaques benefitted not only their kin members but other individuals to whom they showed relatively high social tolerance. We emphasize the roles of complex socio-ecological conditions in facilitating individual prosocial tendencies. Furthermore, these results call for a novel evolutionary framework regarding prosociality that focuses on different forms of interdependence and expands beyond cooperative breeding- and (self-)domesticated species. Significance statementWhat made humans so incredibly prosocial? Examining the evolutionary trajectory of prosocial acts led comparative psychologists to explore various taxa. Empirical evidence so far suggests that enhanced social tolerance and interdependence among individuals facilitate prosociality. Conventionally, despotism is characterized by low group-level tolerance, yet kin favoritism, nepotism, and high interdependence (in support and coalition formation) are also fundamental properties of despotic societies. Under such complex socio-ecological conditions, individual prosocial acts could thus be vital. We found, for the first time, high levels of prosociality in the very despotic Japanese macaques. Individuals benefitted both kin-relatives and others to whom they showed relatively high dyadic social tolerance. This study signifies that prosociality can be favored even in a highly despotic society.

animal behavior and cognition↗