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Puppe, B. (1996). [Social dominance and rank relationships in domestic pigs: a critical review]. Berl Munch Tierarztl Wochenschr, 109(11-12), 457–464.
Abstract: Viewing dominance as an attribute of repeated agonistic interactions between two individuals, the present paper reviews theoretical approaches towards concepts of dominance, methods of measurement, and basic principles and problems connected with social dominance in domestic pigs. Domestic pigs are able to establish social organization structures during all stages of their ontogeny. According to definition, dominance relationships occur when a consistent asymmetry of the result of dyadic agonistic interactions can be assessed. This must not necessarily be connected immediately with a better availability of resources, or a high stability of existing dominance relationships, or a functional definition of dominance. When sociometric characteristics are calculated, it seems to be appropriate to use them for different levels of a biological system (individual, individual pair, group). Investigations of social behaviour and dominance in farm animals should take into account that mechanisms of social behaviour in confined environments are often carried out in parts only. Connections of the dominance concept with other concepts of behavioural regulation should be theoretically considered and further investigated by experimental studies.
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Quaresmini, C., Forrester, G. S., Spiezio, C., & Vallortigara, G. (2014). Social environment elicits lateralized behaviors in gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes). Journal of Comparative Psychology, 128(3), 276–284.
Abstract: The influence of the social environment on lateralized behaviors has now been investigated across a wide variety of animal species. New evidence suggests that the social environment can modulate behavior. Currently, there is a paucity of data relating to how primates navigate their environmental space, and investigations that consider the naturalistic context of the individual are few and fragmented. Moreover, there are competing theories about whether only the right or rather both cerebral hemispheres are involved in the processing of social stimuli, especially in emotion processing. Here we provide the first report of lateralized social behaviors elicited by great apes. We employed a continuous focal animal sampling method to record the spontaneous interactions of a captive zoo-living colony of chimpanzees (Pan troglodytes) and a biological family group of peer-reared western lowland gorillas (Gorilla gorilla gorilla). We specifically focused on which side of the body (i.e., front, rear, left, right) the focal individual preferred to keep conspecifics. Utilizing a newly developed quantitative corpus-coding scheme, analysis revealed both chimpanzees and gorillas demonstrated a significant group-level preference for focal individuals to keep conspecifics positioned to the front of them compared with behind them. More interestingly, both groups also manifested a population-level bias to keep conspecifics on their left side compared with their right side. Our findings suggest a social processing dominance of the right hemisphere for context-specific social environments. Results are discussed in light of the evolutionary adaptive value of social stimulus as a triggering factor for the manifestation of group-level lateralized behaviors. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
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Rands, S. A., Cowlishaw, G., Pettifor, R. A., Rowcliffe, J. M., & Johnstone, R. A. (2003). Spontaneous emergence of leaders and followers in foraging pairs. Nature, 423(6938), 432–434.
Abstract: Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals.
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Reader, S. M., & Laland, K. N. (2002). Social intelligence, innovation, and enhanced brain size in primates. Proc. Natl. Acad. Sci. U.S.A., 99(7), 4436–4441.
Abstract: Despite considerable current interest in the evolution of intelligence, the intuitively appealing notion that brain volume and “intelligence” are linked remains untested. Here, we use ecologically relevant measures of cognitive ability, the reported incidence of behavioral innovation, social learning, and tool use, to show that brain size and cognitive capacity are indeed correlated. A comparative analysis of 533 instances of innovation, 445 observations of social learning, and 607 episodes of tool use established that social learning, innovation, and tool use frequencies are positively correlated with species' relative and absolute “executive” brain volumes, after controlling for phylogeny and research effort. Moreover, innovation and social learning frequencies covary across species, in conflict with the view that there is an evolutionary tradeoff between reliance on individual experience and social cues. These findings provide an empirical link between behavioral innovation, social learning capacities, and brain size in mammals. The ability to learn from others, invent new behaviors, and use tools may have played pivotal roles in primate brain evolution.
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Romero, T., & Aureli, F. (2008). Reciprocity of support in coatis (Nasua nasua). Journal of Comparative Psychology, 122(1), 19–25.
Abstract: Primate sociality has received much attention and its complexity has been viewed as a driving force for the evolution of cognitive abilities. Improved analytic techniques have allowed primate researchers to reveal intricate social networks based on the exchange of cooperative acts and services. Although nonprimates are known to show similar behavior (e.g., cooperative hunting, food sharing, coalitions) there seems a consensus that social life is less complex than in primates. Here the authors present the first group-level analysis of reciprocity of social interactions in a social carnivore, the ring-tailed coati (<xh:i xmlns:search=“http://marklogic.com/appservices/search” xmlns=“http://apa.org/pimain” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xmlns:xh=“http://www.w3.org/1999/xhtml”>Nasua nasua</xh:i>). The authors found that support in aggressive conflicts is a common feature in coatis and that this behavior is reciprocally exchanged in a manner seemingly as complex as in primates. Given that reciprocity correlations persisted after controlling for the effect of spatial association and subunit membership, some level of scorekeeping may be involved. Further studies will be needed to confirm our findings and understand the mechanisms underlying such reciprocity, but our results contribute to the body of work that has begun to challenge primate supremacy in social complexity and cognition. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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Rudran, R. (1973). Adult male replacement in one-male troops of purple-faced langurs (Presbytis senex senex) and its effect on population structure. Folia Primatol (Basel), 19(2), 166–192.
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Scheumann, M., & Call, J. (2004). The use of experimenter-given cues by South African fur seals (Arctocephalus pusillus). Anim. Cogn., 7(4), 224–230.
Abstract: Dogs can use a variety of experimenter-given cues such as pointing, head direction, and eye direction to locate food hidden under one of several containers. Some authors have proposed that this is a result of the domestication process. In this study we tested four captive fur seals in a two alternative object choice task in which subjects had to use one of the following experimenter-given cues to locate the food: (1) the experimenter pointed and gazed at one of the objects, (2) the experimenter pointed at only one of the objects, (3) the experimenter gazed at only one of the objects, (4) the experimenter glanced at only one of the objects, (5) the experimenter pointed and gazed at one of the objects but was sitting closer to one object than to the other, (6) the experimenter pointed only with the index finger at one of the objects, (7) the experimenter presented a replica of one of the objects. The fur seals were able to use cues which involved a fully exposed arm or a head direction, but failed to use glance only, the index finger pointing and the object replica cues. The results showed that a domestication process was not necessary to develop receptive skills to cues given by an experimenter. Instead, we hypothesize that close interactions with humans prior to testing enabled fur seals to uses ome gestural cues without formal training. We also analyzed the behavior of the seals depending on the level of difficulty of the task. Behavioral signs of hesitation increased with task difficulty. This suggests that the fur seals were sensitive to task difficulty.
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Schino, G., di Sorrentino, E. P., & Tiddi, B. (2007). Grooming and coalitions in Japanese macaques (<em>Macaca fuscata</em>): Partner choice and the time frame reciprocation. Journal of Comparative Psychology, 121(2), 181–188.
Abstract: Evidence of a reciprocal exchange of grooming and agonistic support in primates is mixed. In this study, the authors analyzed a large database of grooming and coalitions in captive female Japanese macaques (Macaca fuscata) to investigate their within-group distribution and temporal relations. Macaques groomed preferentially those individuals that groomed them most and supported preferentially those individuals that supported them most. They also supported preferentially those individuals that groomed them most and groomed preferentially those individuals that supported them most. These results were not explained by covariation of grooming and support with third variables such as kinship, rank, or time spent in proximity. However, receiving grooming did not increase the short-term probability of supporting a partner, and being supported did not increase the short-term probability of grooming a partner. The proximate mechanisms underlying the exchange of services were discussed in relation to the time frame of the behavioral choices made by the monkeys. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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Seyfarth, R. M., & Cheney, D. L. (1984). Grooming, alliances and reciprocal altruism in vervet monkeys. Nature, 308(5959), 541–543.
Abstract: Reciprocal altruism refers to the exchange of beneficial acts between individuals, in which the benefits to the recipient exceed the cost to the altruist. Theory predicts that cooperation among unrelated animals can occur whenever individuals encounter each other regularly and are capable of adjusting their cooperative behaviour according to experience. Although the potential for reciprocal altruism exists in many animal societies, most interactions occur between closely related individuals, and examples of reciprocity among non-kin are rare. The field experiments on vervet monkeys which we present here demonstrate that grooming between unrelated individuals increases the probability that they will subsequently attend to each others' solicitations for aid. Vervets appear to be more willing to aid unrelated individuals if those individuals have behaved affinitively toward them in the recent past. In contrast, recent grooming between close genetic relatives appears to have no effect on their willingness to respond to each other's solicitations for aid.
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Seyfarth, R. M., & Cheney, D. L. (1984). The acoustic features of vervet monkey grunts. J Acoust Soc Am, 75(5), 1623–1628.
Abstract: East African vervet monkeys give short (125 ms), harsh-sounding grunts to each other in a variety of social situations: when approaching a dominant or subordinate member of their group, when moving into a new area of their range, or upon seeing another group. Although all these vocalizations sound similar to humans, field playback experiments have shown that the monkeys distinguish at least four different calls. Acoustic analysis reveals that grunts have an aperiodic F0, at roughly 240 Hz. Most grunts exhibit a spectral peak close to this irregular F0. Grunts may also contain a second, rising or falling frequency peak, between 550 and 900 Hz. The location and changes in these two frequency peaks are the cues most likely to be used by vervets when distinguishing different grunt types.
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