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Emotions suffuse much of the language employed by students of animal behavior-from 'social bonding' to 'alarm calls'- yet are carefully avoided as an explicit topic in scientific discourse. Given the increasing interest in human emotional intelligence and the explicit attention in neuroscience to the emotions, both human and nonhuman, the taboo that has reigned for so long in animal behavior research seems outdated. The present review seeks to recall the history of our field in which emotions and instincts were mentioned in the same breath and in which neither psychologists nor biologists felt that animal emotions were off limits. One of the tenets supporting a renewed interest in this topic is to avoid unanswerable questions and to view emotions as mental and bodily states that potentiate behavior appropriate to environmental challenges. Understanding the emotionally deep structure of behavior will be the next frontier in the study of animal behavior. [ABSTRACT FROM AUTHOR]

Postconflict management strategies have been defined as any postconflict interaction that mitigates the negative consequences of the preceding agonistic conflict. Although most studies have investigated postconflict interactions between former opponents or between victims and uninvolved bystanders, interactions between aggressors and bystanders have received much less attention. In this study, we examined a database of 1,102 agonistic interactions and their corresponding postconflict periods in two outdoor-housed groups of captive chimpanzees in order to test the occurrence of postconflict third-party affiliation of aggressors. Our results confirmed the occurrence of appeasement, i.e. postconflict affiliation by a bystander toward an aggressor, but failed to detect the occurrence of postconflict affiliation directed from aggressors toward bystanders. Appeasement rates did not differ according to the sex of the involved individuals. In addition, appeasement occurred more often in the absence of reconciliation than after its occurrence suggesting that appeasement may act as an alternative to reconciliation when the latter fails to occur. Both study groups showed behavioral specificity for appeasement, i.e. context-specific use of certain behaviors, supporting the view that chimpanzees exhibit highly visible explicit postconflict affiliation. Am. J. Primatol. 73:397-404, 2011. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Over the last few decades, comparative cognitive research has focused on the pinnacles of mental evolution, asking all-or-nothing questions such as which animals (if any) possess a theory of mind, culture, linguistic abilities, future planning, and so on. Research programs adopting this top-down perspective have often pitted one taxon against another, resulting in sharp dividing lines. Insight into the underlying mechanisms has lagged behind. A dramatic change in focus now seems to be under way, however, with increased appreciation that the basic building blocks of cognition might be shared across a wide range of species. We argue that this bottom-up perspective, which focuses on the constituent capacities underlying larger cognitive phenomena, is more in line with both neuroscience and evolutionary biology. [Copyright &y& Elsevier]

It has been claimed that capuchin monkeys (Cebus apella) show inequity aversion in relation to food rewards for a simple exchange task. However, other factors may affect the willingness of a monkey to consume foods of high or low value in the presence of a conspecific. In this study, pairs of monkeys were presented with unequally valued foods, but without any task-performance: they simply received the food under four experimental conditions. By looking at the rate of collection and consumption of low-valued cucumber slices we expected to see variation dependent on whether the partner either had 1) cucumber (equity), 2) grape (inequity), 3) inaccessible cucumber or 4) inaccessible grape. Testing 12 adult capuchin monkeys, our findings differed from those of other authors in that the monkeys failed to show negative reactions to inequity, but rather responded with scramble competition (i.e., fast food collection) in the presence of a conspecific without access to food. They also showed facilitated consumption in the presence of a conspecific consuming high-valued food. Possibly, (in)equity plays a different role if food serves as a reward for a task rather than if it is simply made available for consumption. Am. J. Primatol. 69:1–9, 2007. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Social learning is assumed to underlie traditions, yet evidence indicating social learning in capuchin monkeys (Cebus apella), which exhibit traditions, is sparse. The authors tested capuchins for their ability to learn the value of novel tokens using a previously familiar token-exchange economy. Capuchins change their preferences in favor of a token worth a high-value food reward after watching a conspecific model exchange 2 differentially rewarded tokens, yet they fail to develop a similar preference after watching tokens paired with foods in the absence of a conspecific model. They also fail to learn that the value of familiar tokens has changed. Information about token value is available in all situations, but capuchins seem to pay more attention in a social situation involving novel tokens. [ABSTRACT FROM AUTHOR]

Discusses the relational model, a research technique used to study aggression in primates. Placement of conflict resolution in social settings of communities; Prominence of conciliatory behavior after conflict in primates; Intensity of the reconciliation after conflict between individuals who stand to lose a great deal if their relationship deteroorates.

Mother-offspring (MO) relationship quality was investigated to determine its influence on the development of reconciliation—affiliation between opponents shortly after a fight—because it influences what distressed youngsters learn about calming down. Data were longitudinal and cross-sectional observational samples of 38 MO pairs of monkeys across 24 months. An MO relationship quality index (RQI) classified each pair as secure or insecure. Reconciliation emerged in infancy. Secure youngsters had an appeasing conciliatory style, and insecure youngsters had an agitated conciliatory style. Conclusions are that reconciliation develops from the attachment behavior system and MO RQI is related to the particular conciliatory style youngsters develop by affecting how aroused they are by conflict and the subsequent socializing they seek to calm down. [ABSTRACT FROM AUTHOR]

Stable cooperation requires that each party’s pay-offs exceed those available through individual action. The present experimental study on brown capuchin monkeys (Cebus apella) investigated if decisions about cooperation are (a) guided by the amount of competition expected to follow the cooperation, and (b) made instantaneously or only after a period of familiarization. Pairs of adult monkeys were presented with a mutualistic cooperative task with variable opportunities for resource monopolization (clumped versus dispersed rewards), and partner relationships (kin versus nonkin). After pre-training, each pair of monkeys (N=11) was subjected to six tests, consisting of 15 2 min trials each, with rewards available to both parties. Clumped reward distribution had an immediate negative effect on cooperation: this effect was visible right from the start, and remained visible even if clumped trials alternated with dispersed trials. The drop in cooperation was far more dramatic for nonkin than kin, which was explained by the tendency of dominant nonkin to claim more than half of the rewards under the clumped condition. The immediacy of responses suggests a decision-making process based on predicted outcome of cooperation. Decisions about cooperation thus take into account both the opportunity for and the likelihood of subsequent competition over the spoils. [Copyright &y& Elsevier]

Studies the nature or quality of mother-offspring (MO) relationship during development using brown capuchin monkeys. Use of qualitative classification of MO relationship; Role of the empirical ratio of relative affiliation to agonism; Revelation of extensive behavioral differences between secure.

Focuses on the inevitability of evolutionary psychology. Limitations of adaptationism; Resistance to genetic reductionism; Usefulness of evolutionary theory to explain the social behavior of primates.

Focuses on the use of cooperative pulling tasks in assessing cooperative behavior in capuchin monkeys. Impact of visual contact elimination between partners on the success of cooperation; Observation of the monitoring behavior toward partner in cooperative and control tests; Factor affecting the level of coordination in monkeys.

Confirms the correlation between the rate of food transfer in both directions across female-female dyads in Capuchin monkeys. Role of symmetry in affiliative and tolerant tendencies between two individuals in the reciprocity across dyads; Covariation across tests of sharing in both dyadic directions; Indications of control procedures on behavior during food trials.

Spontaneous interactions over fruits and vegetables were observed in a captive group of Cebus apella. The group lacked fully grown males; 3 adult females dominated the remaining 11 individuals, most of which were adolescents and late juveniles. Apart from expressions of interest and unsuccessful attempts to claim food, interactions over food included two types of interindividual food transfer: forced claims (i.e., involuntary transfers) and peaceful sharing. These two categories represented 7.2% and 20.3% of 3,389 observed food interactions, respectively. Sharing of food was subdivided into four categories; the most frequent category was the collection of discarded food items from within reach of the possessor, and the least frequent was active giving of food items by the possessor. The voluntary nature of food transfers was further investigated in an experiment in which two monkeys were placed in adjacent cages with a wire-mesh partition between them. One subject received food; the other did not. Although this setup made it easy for possessors to prevent food transfers, sharing occurred in all 18 tests on different combinations of individuals. In 10 of the tests, possessors were observed to actively push food through the mesh partition to their partner. [ABSTRACT FROM AUTHOR]

Captive studies can make a unique contribution to primate socioecology by documenting species-typical social dispositions under controlled conditions. Recent theories seek to connect the dominance relationships, group cohesiveness, and feeding ecology of primates. The present study explores the first to aspects by comparing the social organization of rhesus (Macaca mulatta) and stumptail monkeys (M. arctoides). Data were collected over a period of eight years, with five different methods, on three well-established captive groups in identical environments. The groups were found to share one characteristic: a clear-cut, linear formal dominance hierarchy as expressed in teeth-bearing displays. The two main study groups (one of each species) differed significantly, however, with respect to nine of eleven behavioral measures. In addition to a previously reported higher frequency of reconciliation in the stumptail group, this group showed 1) more frequent but less severe aggressive behavior, 2) greater symmetry of contests, 3) greater social tolerance, 4) more nonagonistic approaches, and 5) more allogrooming. The differences can be summarized as a contrast in dominance "style," with the stumptails having a more relaxed style and placing greater emphasis on social cohesion than the rhesus monkeys. An egalitarian attitude was also reflected in approach behavior: contacts in the rhesus group were initiated dominants, whereas contacts in the stumptail group were initiated independent of rank. Comparisons with a second rhesus group, and with published reports, suggest that while some of the observed differences are probably representative of the two species, considerably intraspecific variation does exist, and a more comprehensive program of comparative studies is needed. [ABSTRACT FROM AUTHOR]

Teeth-baring in a large captive rhesus monkey group (Macaca mulatta) was observed over a 30-month period. Its directional consistency among adults was significantly higher than that of aggression. The unidirectionality was so extreme that the facial display must be seen as a formal status indicator; ie, a signal of which the direction is independent of short-term contextual variation. As such, it seems adapted for communication about the state of the relationship. Formal dominance relationships among adults could be arranged in a hierarchy which approached perfect linearity. Focal observations demonstrated that teeth-baring was associated with withdrawal. It was uncommon among foraging monkeys, perhaps because dominant animals paid leas attention to their subordinates in this context. The speed of rank acquisition by young females, in terms of received teeth-baring, was highest among peers and lowest against the group's old matriarchs. The age at which dominance over unrelated adult females was achieved correlated negatively with the amount of affiliative contact with these females. This translates into a positive correlation between bonding and rank establishment, indicating that dominance processes may be indistinguishable from social integration. [ABSTRACT FROM AUTHOR]

Presents a study which suggests that sharing mechanisms may be different for adult male capuchins, with males sharing food more readily and less discriminating than females. Methodology used to conduct the study; Discussion based on the results of the study.

Present a study on the development and perpetuation of affiliative networks among female macaques. Transmission of maternal affiliative relations to offspring; Effects of kinship; Predictor of affiliative relations; Copying of maternal social preferences through a process of cultural learning.

Provides information on a study of the social conflict and its aftermath in two captive groups of brown capuchins (ebus apella) an arboreal New World species observing their postconflict behavior in two contexts. Methodology used to conduct the study; Results of the study; Discussion on the results.

Examines the impact of high population density on behavioral pathology in rhesus monkeys, with emphasis on its effect on causing aggression. Reference to socioecological studies conducted on the effects of population on animals behavior; Findings of studies conducted.

Examines two models which predict a relationship between space and aggression in the rhesus monkey. Spatial density model; Coping model; Examination of behavior changes in short-term crowding; Increase in mild aggressive behavior; Adoption of a conflict-avoidance strategy.

Tests a hierarchical multiple regression model of adult social organization in groups of rhesus monkeys, Macaca mulatta. Use of data from three studies on two captive groups; Assumption that matrilineal kinship affects rank distance; Assumed effect of rank distance on affiliative behavior; Testing of model with matrix permutation techniques.

During the evolution of cooperation it may have become critical for individuals to compare their own efforts and pay-offs with those of others. Negative reactions may occur when expectations are violated. One theory proposes that aversion to inequity can explain human cooperation within the bounds of the rational choice model, and may in fact be more inclusive than previous explanations. Although there exists substantial cultural variation in its particulars, this ‘sense of fairness’ is probably a human universal that has been shown to prevail in a wide variety of circumstances. However, we are not the only cooperative animals, hence inequity aversion may not be uniquely human. Many highly cooperative nonhuman species seem guided by a set of expectations about the outcome of cooperation and the division of resources. Here we demonstrate that a nonhuman primate, the brown capuchin monkey (Cebus apella), responds negatively to unequal reward distribution in exchanges with a human experimenter. Monkeys refused to participate if they witnessed a conspecific obtain a more attractive reward for equal effort, an effect amplified if the partner received such a reward without any effort at all. These reactions support an early evolutionary origin of inequity aversion. [ABSTRACT FROM AUTHOR]

Wild female chimpanzees typically migrate to a neighbouring community at the onset of sexual maturity, a process that can be dangerous and unpredictable. To mitigate the risk of rejection in the new community, immigrants may employ several behavioural strategies. During the integration of two chimpanzee females at Royal Burgers' Zoo (Arnhem, The Netherlands) one of the immigrant females rapidly copied a local tradition — the crossed-arm walk — which has been present in the group for over 20 years. She copied the behaviour after meeting only one resident female, and showed the behaviour frequently throughout a 6-month observation period following the introduction. The other immigrant female never adopted the crossed-arm walk, highlighting the variation in behaviour by immigrants upon integration, as well as the potential associated consequences: in a separate observation period 2 years later, the female who copied the local tradition appeared more socially integrated than the other immigrant female. [ABSTRACT FROM AUTHOR]

We have shown that animals compare their own rewards with those of others, and accept or reject rewards according to their relative value. Our aim was not to demonstrate that capuchin monkeys make a human response to inequality, but rather to elucidate evolutionary precursors to inequity aversion. We use this term as in ref. 2 - “people resist inequitable outcomes; that is, they are willing to give up some material pay-off to move in the direction of more equitable outcomes” - and specifically focus on “disadvantageous inequity aversion”. The monkeys in our experiment could not change the reward division, and hence could not actively avoid inequality, but we wanted to determine whether they would at least recognize inequality if subjected to it. We found that the capuchins reacted negatively, refusing to complete the interaction. [ABSTRACT FROM AUTHOR]

Focuses on a study on cooperative hunting among capuchins monkeys. Spontaneous sharing of attractive foods even if separated by a mesh restraint; Demonstration of reciprocality of facilitated taking.

Brown capuchins give distinct calls upon encountering food. Based on studies on other species that point at divisibility of food and audience as critical variables, we predicted that capuchins would adjust their food calling for both the amount of food and the nature of their audience. We predicted that the food-associated call serves to attract conspecifics in certain conditions. Twelve female capuchins were tested in two food-quantity conditions (large and small) and four audience conditions with a control (higher-ranking female, lower-ranking female, high-ranking male, entire group and alone). All subjects called more for larger than smaller amounts and the highest-ranking females called less than others. Subjects called more in the presence of a group than for any other audience, and this applied most strikingly to high-ranking subjects. This result may be related to the presence of kin rather than group size. We also analysed the acoustic parameters of the calls, predicting that, under conditions where call production rose, those acoustic variables associated with heightened arousal would rise in value. However, call production and those acoustic features were not always correlated. These results suggest that food calls in this species do not solely reflect arousal caused by food and are influenced by multiple audience effects. [Copyright &y& Elsevier]

Prescriptive social rules are enforced statistical regularities. The authors investigated whether juvenile chimpanzees (Pan troglodytes) recognize and use enforced statistical regularities to guide dyadic play behavior. They hypothesized (a) that proximity of adults, especially mothers of younger play partners, to play bouts will increase the play signaling of older partners and (b) that when juvenile-juvenile play bouts occur in proximity to adults, older partners will play at a lower intensity than when no adults are present. They found that older and younger partners increase their play signaling in the presence of the mothers of younger partners, particularly as the intensity of play bouts increases. In contrast to their hypothesis, older partners played more roughly when the mothers of younger partners were in proximity. These results suggest that juvenile chimpanzees increase play signaling to prevent termination of the play bouts by mothers of younger partners. [ABSTRACT FROM AUTHOR]

Studies postconflict third-party affiliation in stumptailed macaques. Occurrence of multiple postconflict triadic affiliation of monkeys; Importance of analyzing the different affiliative behavior in postconflict situations; Role of third parties during postconflict period.

Some cercopithecine primates direct disproportionate amounts of grooming, huddling, and agonistic support toward maternal kin. Disproportionate amounts of aggression are also directed toward maternal kin, however, suggesting that mechanisms that restore relationships damaged by aggression, such as reconciliation, might be biased toward these preferred social partners. Studies investigating kinship effects and reconciliation are inconsistent, however, perhaps because of differences in the environmental conditions under which behavior was observed. In order to test the effects of kinship and spatial density on affiliative and reconciliation behavior, we conducted focal and scan rumpling on a group of rhesus monkeys (Macaca mulatta) living in an outdoor corral under low spatial density conditions. We then compared this data to previously published dam on a group of the same species living under higher spatial density conditions. Neither overall grooming nor reconciliation were affected by spatial density once correction procedures were applied. Grooming was kin biased at both study sites, whereas reconciliation was kin biased only in the low-density group. Although data failed to support a Coping Model according to which grooming and reconciliation should go up under higher densities, we suggest that coping may he reflected not so much in overall rates of behavior hut in strategic partner choices, such as the increased importance monkeys under crowded conditions appear to attach to nonkin partners. [ABSTRACT FROM AUTHOR]

In the present study, we seek to relate dominance style with group cohesion in a captive group of Japanese macaques (Macaca fuscata). Social data were gathered on approach rate, result, and direction, aggression rate and intensity, grooming rate and direction, and conciliatory tendency. Data were collected using focal animal sampling and instantaneous scan sampling. Reconciliation data were collected using ad libitum observations of aggression with ten-minute post-conflict and matched-control focal observations. Data were compared to prior studies on rhesus (M. mulatta) and stumptail macaques (M. arctoides) living in similar environments. Each species demonstrated the presence of a formalized dominance hierarchy based on the teeth-baring display. The Japanese macaque group showed a lower rate of approach with a higher proportion of negative outcomes than either of the other species. Rates of aggression and reconciliation were also lower in the study troop, suggesting a strict hierarchy while maintaining an optimal nearest-neighbor distance. Overall, this group of Japanese macaques was less sociable than other groups of the same species, perhaps due to a history of individual removals. [ABSTRACT FROM AUTHOR]