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Comparison of social hierarchies computed using direct observations of behaviors (Direct Observations Ranking) and MALT conflicts (Automatic Ranking) in three datasets (rows) and using three different measures of social hierarchies (columns). For all panels, the gray line represents simple least squares regression and the dashed line the reference. Each row represents a given dataset analysis and each column a different method to compute the social hierarchy. In panels (A,D,G), the social hierarchies were calculated using the ordinal ranks obtained with the David's Score (DS); Correlation coefficient R and p values corresponded to
Source publication
Among animals’ societies, dominance is an important social factor that influences inter-individual relationships. However, assessing dominance hierarchy can be a time-consuming activity which is potentially impeded by environmental factors, difficulties in the recognition of animals, or through the disturbance of animals during data collection. Her...
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Context 1
... coefficient R and p values were from Pearson correlation. Sample sizes were 20, 19, and 18 individuals for the dataset 1 (A,B,C), 2(D,E,F) and 3(G,H,I), respectively. For graphical purposes only, all data were z-scored. ...
Citations
Inhibitory control, the inhibition of impulsive behaviours, is believed to be key in navigating a complex social environment. Species characterised by higher social tolerance, living in more complex groups, with more diverse relationships, face higher uncertainty regarding the outcome of social interactions and, therefore, would benefit from employing more inhibitory strategies. To date, little is known about the selective forces that favour the evolution of inhibitory control. In this study, we compared inhibitory control skills in three closely related macaque species which differ in their social tolerance style. We tested 66 macaques from two institutions ( Macaca mulatta , low tolerance; M. fascicularis , medium tolerance; and M. tonkeana , high tolerance) using a battery of validated inhibitory control touchscreen tasks. Higher social tolerance was associated with enhanced inhibitory control performances. More tolerant species were less impulsive and less distracted by pictures of unknown conspecifics. Interestingly, we did not find evidence that social tolerance degree was associated with performance in reversal learning. Overall, our results support the hypothesis that evolution has promoted the development of socio-cognitive skills to cope with the demands related to the complexity of the social environment.
Living in a complex social environment requires primates to manage their emotions and inhibit impulsive behaviours. The cognitive processes that underpin these behaviours, crucial in many aspects of everyday life, are defined as inhibitory control. In animal studies, the various paradigms designed to measure inhibitory control often suffer from a lack of systematic validation. Moreover, striking individual variations in inhibitory control performances are often largely ignored and their causes rarely considered. Finally, little is known about the selective forces that shape the evolution of inhibitory control. It has been suggested that one route by which this ability can be enhanced is through selection on social tolerance. Hence the aim of this project was threefold: 1-to develop a battery of inhibitory control tasks in non-human primates 2-to use this task battery to systematically investigate individual variability and its most common causes 3-on a broader evolutionary scale, to compare the inhibitory control skills in three species which differ in social tolerance style. For that purpose, we tested 66 macaques (28 Macaca mulatta, 19 M. fascicularis and 18 M. tonkeana) in a battery of touchscreen tasks assessing three main components of inhibitory control: inhibition of a distraction (using a Distraction task), inhibition of an impulsive action (using a Go/No-go task) and inhibition of a cognitive set (using a Reversal learning task). We found that all tasks were reliable and effective at measuring the inhibition of an impulsive and automatic response. We then demonstrated individual variations, sex and age differences in inhibitory control performances. Finally we demonstrated that the least tolerant species were poorer at controlling their emotions and impulsions compared to other species. Overall, this project will help to get more insight into the multifaceted structure and the evolution of inhibitory control in primates.
Inhibitory control, the inhibition of impulsive behaviours, is believed to be key in navigating a complex social environment. Species characterised by higher social tolerance, living in more complex groups, with more diverse relationships, face higher uncertainty regarding the outcome of social interactions, and therefore, would benefit from employing more inhibitory strategies. To date, little is known about the selective forces that favour the evolution of inhibitory control. In this study, we compared inhibitory control skills in three closely related macaque species which differ in their social tolerance style. We tested 66 macaques from two institutions ( Macaca mulatta , low tolerance; M. fascicularis , medium tolerance; and M. tonkeana , high tolerance) using a battery of validated inhibitory control touchscreen tasks. Higher social tolerance was associated with enhanced inhibitory control performances. More tolerant species were less impulsive and less distracted by pictures of unknown conspecifics. Interestingly, we did not find evidence that social tolerance degree was associated with performance in reversal learning. Overall, our results support the hypothesis that evolution has promoted the development of socio-cognitive skills to cope with the demands related to the complexity of the social environment.
