Periodic Reporting for period 1 - CooPMacaque (Why do individuals cooperate? Exploring the behavioural, cognitive, and hormonal mechanisms governing cooperation in macaques.)
Reporting period: 2020-09-01 to 2022-08-31
The MSC Action is titled “Why do individuals cooperate? Exploring the behavioural, cognitive, and hormonal mechanisms governing cooperation in macaques.” The project investigates the evolution of partner choice during cooperation in macaque societies. Cooperation in animal societies is essential as it ensures the survival and reproduction of individuals, thus significantly impacting their fitness. Understanding cooperation among kin and non-kin members in non-human animals can provide us with scientific insights into how humans cooperate and choose their cooperation partners. Despite numerous theoretical explanations, empirical evidence on why and how animals cooperate and select their partners is scarce. Furthermore, in-depth knowledge of the proximate drivers of cooperation can provide critical insights that may benefit a range of disciplines other than life science, such as political science, social science, economics, and comparative psychology. CooPMacaque investigated the proximate mechanisms that underlie cooperation and shed light on the evolution of cooperative interactions.
The project specifically looked at personality, prosociality, and dominance-rank (i.e. asymmetry in resource-holding power) relationships, in predicting partner choice during cooperation. The individual-level information, i.e. personalities, was paramount in applied biological fields, such as welfare science. The project not only built rigorous scientific knowledge on macaque personalities but also proposed animal welfare measures, especially in captivity. Moreover, the “other-regarding behaviour”, i.e. prosociality, was also studied as one of the proximate drivers facilitating cooperation. Finally, cooperative interactions were investigated across different species, emphasising partner choice and its underlying mechanisms (i.e. the abovementioned proxies).
The primary aim of this MSC Action was to address how individuals choose their cooperation partners. I proposed and tested different species of macaques to answer this question due to their close phylogenetic relatedness yet different ‘social tolerance levels’. Formally, the objectives were – (i) investigation of the personalities of macaques, (ii) assessment of prosocial motivations in macaques, (iii) quantification of the hormonal mechanisms of cooperation and finally, (iv) testing cooperation and partner choice across different species of macaques. In addition, an objective was to foster the individual development of the experienced researcher. In this project, the objectives and goals have been addressed via six different work packages (WP): WP1 – behavioural observations and hormonal sampling, WP2 – personality tests, WP3 – prosociality tests, WP4 – cooperation tests, WP5 – Training by attending courses, teaching and supervision of students, and finally WP6 – dissemination of work and outreach.
The project specifically looked at personality, prosociality, and dominance-rank (i.e. asymmetry in resource-holding power) relationships, in predicting partner choice during cooperation. The individual-level information, i.e. personalities, was paramount in applied biological fields, such as welfare science. The project not only built rigorous scientific knowledge on macaque personalities but also proposed animal welfare measures, especially in captivity. Moreover, the “other-regarding behaviour”, i.e. prosociality, was also studied as one of the proximate drivers facilitating cooperation. Finally, cooperative interactions were investigated across different species, emphasising partner choice and its underlying mechanisms (i.e. the abovementioned proxies).
The primary aim of this MSC Action was to address how individuals choose their cooperation partners. I proposed and tested different species of macaques to answer this question due to their close phylogenetic relatedness yet different ‘social tolerance levels’. Formally, the objectives were – (i) investigation of the personalities of macaques, (ii) assessment of prosocial motivations in macaques, (iii) quantification of the hormonal mechanisms of cooperation and finally, (iv) testing cooperation and partner choice across different species of macaques. In addition, an objective was to foster the individual development of the experienced researcher. In this project, the objectives and goals have been addressed via six different work packages (WP): WP1 – behavioural observations and hormonal sampling, WP2 – personality tests, WP3 – prosociality tests, WP4 – cooperation tests, WP5 – Training by attending courses, teaching and supervision of students, and finally WP6 – dissemination of work and outreach.
The work carried out during the fellowship was ascribed to six different WPs. This section summarises and describes the results and outputs of each WP.
WP1 and WP2: Using the multi-method approach of behavioural observations and experiments, I found different personality traits in the different species of macaques -
M. fuscata: Activity, Anxiety, Affiliation.
M. fascicularis: Activity-Sociability, Anxiety-Attention.
M. sylvanus: Activity-Sociability, Anxiety, Dominance, Affiliation.
M. silenus: Persistence, Sociability, Affiliation, Anxiety.
M. nigra: Persistence, Activity-Exploration, Affiliation, Boldness-Tension.
WP3:Prosociality tests: I found that more despotic the species is the more prosocial they are, it was contrary to the hypothesis proposed.
WP4:Cooperation tests: Similar to prosociality results, the findings follow an opposite trend than what was hypothesised. That means despotic species have been found to be more cooperative in terms of success than socially tolerant species. In other words, cooperation success increased with decreasing egalitarianism.
WP1 and WP2: Using the multi-method approach of behavioural observations and experiments, I found different personality traits in the different species of macaques -
M. fuscata: Activity, Anxiety, Affiliation.
M. fascicularis: Activity-Sociability, Anxiety-Attention.
M. sylvanus: Activity-Sociability, Anxiety, Dominance, Affiliation.
M. silenus: Persistence, Sociability, Affiliation, Anxiety.
M. nigra: Persistence, Activity-Exploration, Affiliation, Boldness-Tension.
WP3:Prosociality tests: I found that more despotic the species is the more prosocial they are, it was contrary to the hypothesis proposed.
WP4:Cooperation tests: Similar to prosociality results, the findings follow an opposite trend than what was hypothesised. That means despotic species have been found to be more cooperative in terms of success than socially tolerant species. In other words, cooperation success increased with decreasing egalitarianism.
The project results have impact on fields other than biological sciences. The project found the first experimental evidence of proactive prosociality in a despotic species like the Japanese macaques. Our results are, therefore, not only an important addition to the field studying the evolution of altruistic behavior, but also urgently call for an evolutionary framework regarding prosociality that focuses on different forms of interdependence which expand beyond the confines of cooperative breeding- and self-domesticated species. We also put much weightage on exploring intraspecific variation in different contexts and project a more general ‘interdependency hypothesis’ to unravel the evolution of prosociality. I expect these findings to be of significant interest to behavioral biologists, comparative psychologists, anthropologists, social scientists, zoologists and even political scientists.
The research also had an impact on the current welfare practices at different zoos. Based on the findings of the personality studies on lion-tailed macaques, welfare measures have been suggested to Diergaarde Blijdorp. Discussions took place to increase their lion-tailed and crested macaque welfare.
The research also had an impact on the current welfare practices at different zoos. Based on the findings of the personality studies on lion-tailed macaques, welfare measures have been suggested to Diergaarde Blijdorp. Discussions took place to increase their lion-tailed and crested macaque welfare.