Nicolas Claidière
Laboratoire de psychologie cognitive
Aix-Marseille University, CNRS
13331 Marseille, France

Computerized assessment of dominance hierarchy in baboons (Papio papio)

Gullstrand, J., Claidière, N., & Fagot, J. (2021). Computerized assessment of dominance hierarchy in baboons (Papio papio). Behavior research methods. doi:10.3758/s13428-021-01539-z

Abstract: Dominance hierarchies are an important aspect of Primate social life, and there is an increasing need to develop new systems to collect social information automatically. The main goal of this research was to explore the possibility to infer the dominance hierarchy of a group of Guinea baboons (Papio papio) from the analysis of their spontaneous interactions with freely accessible automated learning devices for monkeys (ALDM, Fagot & Bonté Behavior Research Methods, 42, 507–516, 2010). Experiment 1 compared the dominance hierarchy obtained from conventional observations of agonistic behaviours to the one inferred from the analysis of automatically recorded supplanting behaviours within the ALDM workstations. The comparison, applied to three different datasets, shows that the dominance hierarchies obtained with the two methods are highly congruent (all rs ≥ 0.75). Experiment 2 investigated the experimental potential of inferring dominance hierarchy from ALDM testing. ALDM data previously published in Goujon and Fagot (Behavioural Brain Research, 247, 101–109, 2013) were re-analysed for that purpose. Results indicate that supplanting events within the workstations lead to a transient improvement of cognitive performance for the baboon supplanting its partners and that this improvement depends on the difference in rank between the two baboons. This study therefore opens new perspectives for cognitive studies conducted in a social context.

It happened to a friend of a friend: inaccurate source reporting in rumour diffusion

Altay, S., Claidière, N., & Mercier, H. (2020). It happened to a friend of a friend: Inaccurate source reporting in rumour diffusion. Evolutionary Human Sciences, 2, E49. doi:10.1017/ehs.2020.53

Abstract: People often attribute rumours to an individual in a knowledgeable position two steps removed from them (a credible friend of a friend), such as ‘my friend’s father, who’s a cop, told me about a serial killer in town’. Little is known about the influence of such attributions on rumour propagation, or how they are maintained when the rumour is transmitted. In four studies (N = 1824) participants exposed to a rumour and asked to transmit it overwhelmingly attributed it either to a credible friend of a friend, or to a generic friend (e.g. ‘a friend told me about a serial killer in town’). In both cases, participants engaged in source shortening: e.g. when told by a friend that ‘a friend told me …’ they shared the rumour as coming from ‘a friend’ instead of ‘a friend of friend’. Source shortening and reliance on credible sources boosted rumour propagation by increasing the rumours’ perceived plausibility and participants’ willingness to share them. Models show that, in linear transmission chains, the generic friend attribution dominates, but that allowing each individual to be exposed to the rumour from several sources enables the maintenance of the credible friend of a friend attribution.

Baboons living in larger social groups have bigger brains

Meguerditchian, A., Marie, D., Margiotoudi, K., Roth, M., Nazarian, B., Anton, J.-L., & Claidière, N. (2020). Baboons (Papio anubis) living in larger social groups have bigger brains. Evolution and Human Behavior. doi:/10.1016/j.evolhumbehav.2020.06.010

Abstract: The evolutionary origin of Primates’ exceptionally large brains is still highly debated. Two competing explanations have received much support: the ecological hypothesis and the social brain hypothesis (SBH). We tested the validity of the SBH in (n=82) baboons (Papio anubis) belonging to the same research centre but housed in groups with size ranging from 2 to 63 individuals. We found that baboons living in larger social groups had larger brains. This effect was driven mainly by white matter volume and to a lesser extent by grey matter volume but not by the cerebrospinal fluid. In comparison, the size of the enclosure, an ecological variable, had no such effect. In contrast to the current re-emphasis on potential ecological drivers of primate brain evolution, the present study provides renewed support for the social brain hypothesis and suggests that the social brain plastically responds to group size. Many factors may well influence brain size, yet accumulating evidence demonstrates that the complexity of social life is an important determinant of brain size in primates.

Action-matching biases in monkeys

O’Sullivan, E. P., Claidière, N., & Caldwell, C. A. (2017). Action-matching biases in monkeys (Sapajus spp.) in a stimulus–response compatibility task: Evaluating experience-dependent malleability. Journal of Comparative Psychology, 131(4), 337-347.

Abstract: Stimulus–response (S–R) compatibility effects occur when observing certain stimuli facilitate the performance of a related response and interfere with performing an incompatible or different response. Using stimulus–response action pairings, this phenomenon has been used to study imitation effects in humans, and here we use a similar procedure to examine imitative biases in nonhuman primates. Eight capuchin monkeys (Sapajus spp.) were trained to perform hand and mouth actions in a stimulus–response compatibility task. Monkeys rewarded for performing a compatible action (i.e., using their hand or mouth to perform an action after observing an experimenter use the same effector) performed significantly better than those rewarded for incompatible actions (i.e., performing an action after observing an experimenter use the other effector), suggesting an initial bias for imitative action over an incompatible S–R pairing. After a predetermined number of trials, reward contingencies were reversed; that is, monkeys initially rewarded for compatible responses were now rewarded for incompatible responses, and vice versa. In this 2nd training stage, no difference in performance was identified between monkeys rewarded for compatible or incompatible actions, suggesting any imitative biases were now absent. In a 2nd experiment, 2 monkeys learned both compatible and incompatible reward contingencies in a series of learning reversals. Overall, no difference in performance ability could be attributed to the type of rule (compatible–incompatible) being rewarded. Together, these results suggest that monkeys exhibit a weak bias toward action copying, which (in line with findings from humans) can largely be eliminated through counterimitative experience.

Other better vs. self better in baboons

Dumas, F., Fagot, J., Davranche, K., & Claidière, N. (2017). Other better versus self better in baboons: an evolutionary approach of social comparison. Proceedings of the Royal Society B: Biological Sciences, 284(1855). doi:10.1098/rspb.2017.0248

Abstract: Comparing oneself with others is an important characteristic of human social life, but the link between human and non-human forms of social comparison remains largely unknown. The present study used a computerized task presented in a social context to explore psychological mechanisms supporting social comparison in baboons and compare major findings with those usually observed in humans. We found that the effects of social comparison on subject’s performance were guided both by similarity (same vs different sex) and task complexity. Comparing oneself with a better off other (upward comparison) increased performance when the other was similar rather than dissimilar, and a reverse effect was obtained when the self was better (downward comparison). Furthermore, when the other was similar, upward comparison led to a better performance than downward comparison. Interestingly, the beneficial effect of upward comparison on baboons’ performance was only observed during simple task. Our results support the hypothesis of shared social comparison mechanisms in human and nonhuman primates.

Figure 2. (a) Estimated differences in reaction times from the averaged model for the three explanatory variables, task complexity (simple versus complex), comparison (downward/self better versus upward/other better) and similarity (same sex versus different sex). Error bars represent standard errors. Horizontal bars indicate a significant difference between the two conditions. (b) For comparison purposes, this graph illustrates the main results of Tesser et al.’s study on social comparison effects in humans [8].

Emotion-Cognition Interaction in Nonhuman Primates

Blanchette, I., Marzouki, Y., Claidière, N., Gullstrand, J., & Fagot, J. (2016). Emotion-Cognition Interaction in Nonhuman Primates. Psychological Science, 28(1), 3-11.

Abstract: It is well established that emotion and cognition interact in humans, but such an interaction has not been extensively studied in nonhuman primates. We investigated whether emotional value can affect nonhuman primates’ processing of stimuli that are only mentally represented, not visually available. In a short-term memory task, baboons memorized the location of two target squares of the same color, which were presented with a distractor of a different color. Through prior long-term conditioning, one of the two colors had acquired a negative valence. Subjects were slower and less accurate on the memory task when the targets were negative than when they were neutral. In contrast, subjects were faster and more accurate when the distractors were negative than when they were neutral. Some of these effects were modulated by individual differences in emotional disposition. Overall, the results reveal a pattern of cognitive avoidance of negative stimuli, and show that emotional value alters cognitive processing in baboons even when the stimuli are not physically present. This suggests that emotional influences on cognition are deeply rooted in evolutionary continuity.