Reconciliation and variation in post-conflict stress in Japanese macaques (Macaca fuscata fuscata): testing the integrated hypothesis

Reconciliation in primates, a post-conflict affiliative interaction between former opponents, appears to have two functions: (1) to repair relationship damaged by aggression such that animals who share more valuable relationships are more likely to reconcile, and (2) to reduce the post-conflict uncertainty and stress of former combatants. The 'integrated hypothesis' of reconciliation links these functions by arguing that the disturbance of a valuable relationship by aggression should result in particularly high levels of stress, which in turn should facilitate efforts to reconcile and thus gain relief from post-conflict stress. A key prediction of the integrated hypothesis is that victims of aggression suffer more stress following conflicts with individuals with whom they share a valuable relationship. In this article, we test the integrated hypothesis by observing the post-conflict behaviour of victims among a free-ranging provisioned troop of Japanese macaques (Macaca fuscata fuscata) living in Shiga Heights, Nagano, Japan. In this troop, monkeys reconciled roughly one in seven conflicts. The only factor that we could significantly relate to the occurrence of reconciliation was kinship; kin reconciled more frequently than non-kin did. Receiving aggression increased and reconciliation reduced the probability of being re-attacked after aggressive interactions, supporting the hypothesis that reconciliation repairs relationships. Victims' self-directed behaviour (SDB) – a behavioural index of stress comprising increases in scratching, self-grooming, and body-shaking – was elevated following aggression but decreased rapidly following reconciliation, supporting the idea that reconciliation functions to reduce post-conflict stress. Post-conflict SDB varied as follows: (1) victims showed a higher level of stress following aggression with kin than with non-kin, and (2) juvenile victims were less distressed than adults. The level of post-conflict SDB performed by juveniles following conflicts with kin was indistinguishable from that performed by adults but was greatly reduced following attacks from non-kin. These results indicate that post-conflict SDB keenly reflects the value of relationships between opponents, and that the post-conflict behaviour of free-ranging Japanese macaques fits the predictions of the integrated hypothesis. Accepted after revision: 11 September 2001 Electronic Publication     

Aggressive behavior in a confined troop of Japanese macaques: Effects of density,season, and gender

A troop of Japanese macaques (Macaca fuscata) confined in a 2-acre outdoor corral increased from 107 to 192 individuals during the 5-year tenure of a project that assessed the effects of density, season, and gender on the expression of adult aggressive behavior. Two statistical subgroups of 16 males and 28 females that were adults at the start of the project and that survived until its completion were studied intensively. There were significant season and sex differences in all groups: males were much more aggressive than females, and males were most aggressive during the fall and and winter mating season; females were most aggressive during the spring and summer birth season. Only the 16 adult males increased their frequency of aggressive behavior as the population density increased. This increase was due to the greater number of potential antagonists available each year.     

Object individuation using property/kind information in rhesus macaques (Macaca mulatta)

Around 1 year of age, infants develop the ability to individuate objects in the absence of spatiotemporal information. Some have proposed that this capacity relies on the emergence of language and, in particular, that comprehending an object's label is required to individuate it as a particular kind. One approach to testing this hypothesis is to conduct experiments on pre-linguistic human infants. A second is to test non-linguistic animals. We followed the second approach, exploring whether semi-free-ranging rhesus macaques can individuate objects using property/kind information. To make the results most directly comparable, we adapted a reaching paradigm used to examine property/kind individuation in infants. Results from three experiments demonstrate that, like 12-month-old infants, adult rhesus macaques can use both spatiotemporal and property/kind information to individuate food objects. In a fourth experiment designed to examine which properties are used to individuate food objects, results revealed that rhesus use color, but not shape. These results, together with experiments involving different procedures, provide support for the conclusion that in the absence of linguistic abilities, some non-human primates spontaneously use property/kind information to individuate objects.     

Variability in behavior frequencies and consistency in transactions across seasons in captive Japanese macaques (Macaca fuscata)

Consistent interspecific differences are found in macaque species, ranging from highly hierarchical and nepotistic societies to more tolerant and open social organizations. It still remains to be demonstrated whether intraspecific variation is narrower than interspecific variation. Herein, we quantified social behavior in a captive group of Japanese macaques (Macaca fuscata) to estimate the range of intraspecific variation for a full array of measurements in three different seasons. Despite an increased frequency of aggression found on the part of males during the mating season, the form of the behaviors performed remained relatively unchanged. Transactions during conflicts, approaches, or grooming did not undergo significant variations in relation to season. Frequencies and durations seemed more sensitive to demographic and environmental variations. The values measured in the study group are representative of the Japanese macaque. The results validate the use of transaction measurements in interspecific comparisons, providing that additional factors such as age and sex are taken into account. Aggr. Behav. 29:81–93, 2003. © 2003 Wiley‐Liss, Inc.     

Conditioning of appetitive and consummatory sexual behavior in male Japanese quail.

Two different types of stimulus objects, a live female quail artificially adorned with bright orange feathers and an inanimate toy dog, served as conditioned stimuli. For subjects in experimental groups, the conditioned stimuli were presented shortly before access to a sexually receptive normal female quail. For subjects in control groups, exposure to the conditioned stimuli was unpaired with copulatory opportunity. Subjects in the experimental but not in the control groups quickly came to approach the location of the conditioned stimulus objects. When an adorned female quail served as the conditioned stimulus, the conditioned approach behavior was controlled by a combination of the presence of the orange adornments and the visual cues of the head and neck of the female bird, and the approach behavior persisted as the adorned female moved to new locations. When the toy dog served as the conditioned stimulus, the conditioned approach behavior was limited to the spatial cues that surrounded the toy dog during conditioning trials. Although both types of stimulus objects evoked conditioned approach behavior, only the adorned female stimulus supported copulatory behavior. This last finding indicates that copulatory behavior can become redirected toward novel stimuli as a result of conditioning, but only under special circumstances. The results are consistent with the suggestion that appetitive components of reproductive behavior are more susceptible to conditioning than consummatory components. Possible reasons for this are discussed, together with implications of the results for the contribution of conditioning processes to sexual selection.     

The role of modeling in prevention and extinction of phobic behaviour in cynomolgus monkeys (Macaca Fascicularis)

In previous studies surrogate reared cynomolgus monkeys have been shown to become phobic of an unprepared harmless object. In the present study an attempt was made to prevent the development of phobic behaviour in young monkeys and to extinguish avoidance behaviour in phobic monkeys. In the first experiment subjects were exposed to the object in company of their (surrogate) mothers which approached the object. In the second experiment phobic subjects were exposed to the object in company of non-phobic conspecifics which approached the object. The results of the first experiment show that modeling was unsuccessful in preventing the acquisition of phobia in the surrogate-reared monkeys but seemed successful in accelerating approach in the mother-reared subjects. The results of the second experiment show that during the modeling treatment the phobic subjects followed the model and approached the object. However, in post treatment tests all subjects but one relapsed into avoidance. The effect of modeling during treatment is interpreted in terms of coaclive facilitation.     

Sex categorization of conspecific pictures in Japanese monkeys (Macaca fuscata)

We investigated whether monkeys discriminate the sex of individuals from their pictures. Whole-body pictures of adult and nonadult monkeys were used as stimuli. Two male Japanese monkeys were trained for a two-choice sex categorization task in which each of two choice pictures were assigned to male and female, respectively. Following the training, the monkeys were presented with novel monkey pictures, and whether they had acquired the categorization task was tested. The results suggested that while monkeys discriminate between the pictures of adult males and females, discrimination of nonadult pictures was difficult. Partial presentations of the pictures showed that conspicuous and sexually characteristic parts (i.e., underbellies including male scrotums or breasts including female nipples) played an important role in the sex categorization.     

A comparison of body perceptions in relation to measured body composition in young Japanese males and females

The body composition of 139 Japanese females and 84 Japanese males (aged 18–30 years) was measured using anthropometry to assess gender differences in body perceptions in relation to their measured values. Participants were asked to rate perceptions of their own “heaviness” and “fatness” and these were compared to their BMI and percent body fat (%BF). Japanese females showed a significantly greater desire to lose body weight (−4.20 ± 0.6 kg) compared to males (0.27 ± 1.4 kg). Females also showed poor understanding of their “heaviness” and “fatness” in relation to actual body composition compared to males. The results confirmed distinct gender differences in body perception in relation to actual body composition and attitudes to weight management. Further promotion of “healthy” body image is recommended for the Japanese population.     

我国骨髓移植的过去,现在与未来

骨髓移植是近２０年来得到飞速发展的一项高科技治疗方法,目前广泛应用于治疗一些恶性和非恶性疾病,如：急,慢性白血病,恶性肿瘤,再生障碍性贫血,先天免疫失调和代谢障碍病等,我国于５０年代末开始实验性骨髓移植研究,现已有众多单位可以开展此项工作,但仍不能满足患者迫切需要,本文回顾了世界和我国骨髓移植发展史,就我国骨髓移植所存在的问题,面临的挑战和机遇以及今后的发展前景做了简要的论述。     

Perception of the motion trajectory of objects from moving cast shadows in infant Japanese macaques (Macaca fuscata)

The shadows cast by moving objects enable human adults and infants to infer the motion trajectories of objects. Nonhuman animals must also be able to discriminate between objects and their shadows and infer the spatial layout of objects from cast shadows. However, the evolutionary and comparative developmental origins of sensitivity to cast shadows have not been investigated. In this study, we used a familiarity/novelty preferential looking procedure to assess the ability of infant macaques, aged 7–24 weeks, to discriminate between a ‘depth’ display containing a ball and cast shadow moving diagonally and an ‘up’ display containing a ball with a diagonal trajectory and a shadow with a horizontal trajectory. The infant macaques could discriminate the trajectories of the balls based on the moving shadows. These findings suggest that the ability to perceive the motion trajectory of an object from the moving shadow is common to both humans and macaques.     

Conformism in the food processing techniques of white-faced capuchin monkeys (Cebus capucinus)

Researchers of “culture” have long been interested in the role of social learning in establishing patterns of behavioral variation in wild animals, but very few studies examine this issue using a developmental approach. This 7-year study examines the acquisition of techniques used to process Luehea candida fruits in a wild population of white-faced capuchin monkeys, Cebus capucinus, residing in and near Lomas Barbudal Biological Reserve, Costa Rica. The two techniques for extracting seeds (pounding or scrubbing) were approximately equal in efficiency, and subjects experimented with both techniques before settling on one technique—typically the one they most frequently observed. In a sample of 106 subjects that had already settled on a preferred technique, the females adopted the maternal technique significantly more often than expected by chance, but the males did not. Using a longitudinal approach, I examined the acquisition of Luehea processing techniques during the first 5 years of life. Regression analysis revealed that the technique most frequently observed (measured as proportion of Luehea processing bouts observed that used pounding as opposed to scrubbing) significantly predicted the technique adopted by female observers, particularly in the second year of life; the amount of impact of the observed technique on the practiced technique was somewhat less significant for male observers. These results held true for (a) observations of maternal technique only, (b) observations of technique used by all individuals other than the mother, and (c) observations of maternal and non-maternal techniques combined. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Complexity in object manipulation by Japanese macaques (Macaca fuscata): a cross-sectional analysis of manual coordination in stone handling patterns

Defined as a spontaneous stone-directed noninstrumental manipulative behavior, and comprised of multiple one-handed and (a)symmetrical/(un)coordinated two-handed patterns, stone handling (SH) is a good candidate for the study of complexity in object manipulation. We present a cross-sectional developmental analysis of SH complexity in Japanese macaques (Macaca fuscata), through the combined investigation of bimanuality, coordination, and symmetry in hand use. Bimanual SH patterns were more frequent than unimanual patterns. Among bimanual patterns, coordinated actions were more frequent than uncoordinated ones. We recorded five asymmetrical coordinated SH patterns with manual role differentiation, a form of hand use reminiscent of complex actions involving the use of tools in monkeys and apes. Bimanuality in SH was affected by body posture. Aging individuals performed less bimanual and less coordinated SH patterns than younger individuals. Our result on senescent males performing less bimanual patterns than senescent females was consistent with sex differences found in the late deterioration of complex manual movements in other species. Although some SH patterns represent a high degree of behavioral complexity, our results suggest that SH behavior is not as complex as tool-use or tool-manufacture in other nonhuman primates and hominids.     

Patterns of agonistic interactions in three species of macaque (Macaca mulatta,M fascicularis,M tonkeana)

Patterns of aggression and response to aggression were studied in three groups of macaques living in semiliberty, each group representing a different species: Macaca mulatta, M fascicularis, and M tonkeana. In Macaca mulatta, intensity of aggression is high (biting is frequent) and symmetry in aggression is low: the aggressee most often flees or submits. In Macaca tonkeana, in contrast, biting is exceptional, aggression is very often bidirectional, and appeasement behaviors are frequently observed. Intermediate patterns are found in Macaca fascicularis with, in addition, especially frequent mild forms of submission. It is argued that relationships exist between intensity of aggression, symmetry in aggression, and development of behaviors controlling aggresssion. Whether balances between these variables are species-specific is discussed.     

Personality in Barbary macaques (Macaca sylvanus): Temporal stability and social rank

Tracing the evolutionary origins of species-specific personality structures requires comparative personality research. We used a 51 item questionnaire to examine the personality structure of 26 semi-free-ranging Barbary macaques assessed at two time points. Principal-components analysis revealed four dimensions: Friendliness, Activity/Excitability, Confidence, and Opportunism. These dimensions were reliable across raters, stable over time, and both similar to and different from the personality dimensions of free-ranging rhesus macaques and male Hanuman langurs. We modeled the relationships between Confidence and a behavioral measure of rank at both time points. The stability of rank over time could be explained by Confidence but not vice versa. These findings highlight how interspecies differences in personality structure reflect personality evolution and how rank is related to personality.     

Genetic and experiential manipulation of fear-related behavior in Japanese quail chicks (Coturnix coturnix japonica)

We examined effects of environmental enrichment and regular handling on fear-related responses in chicks of Japanese quail (Coturnix coturnix japonica) selected over several generations for short or long tonic immobility (STI and LTI, respectively). STI chicks froze less, vocalized and walked sooner and more in an open field, emerged sooner from a hole-in-the-wall box, and showed shorter TI reactions than did chicks of the LTI line. Similarly, environmental enrichment reduced silence and inactivity in the open field, accelerated emergence, and attenuated TI. Regular handling promoted open-field vocalization and reduced the duration of TI but exerted no other significant effects. Principal component analysis showed that the responses in the 3 tests were not independent, which implies that they measured the same underlying factor. The genetic and experiential manipulation of stimulus-specific fears and of general fearfulness is discussed.     

The Portuguese version of the Knowledge of Infant Development Inventory-P (KIDI-P)

Several studies show that parental knowledge about child development and education is relevant to parenting actions. Considering that the lack of assessment instruments specific to this domain in Portugal is an obstacle to cross-cultural research and programme evaluation, the objective of this study was to make available a Portuguese version of the Knowledge of Infant Development Inventory-P (KIDI-P). This inventory (58 items) allows for the calculation of three summary scores (Attempted, Accuracy and Total) that reflect correctness and confidence in one's knowledge. The Portuguese version of the KIDI-P confirmed a unidimensional structure and revealed good internal consistency (α = .89). In a sample of 252 mothers and fathers, educational level showed to be related to KIDI-P scores, unlike parents’ sex and age.