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     

Population growth and social structure of confined colonies of mongolian gerbils: Scent gland size and marking behaviour as indices of social status

Male gerbils have larger ventral scent glands, and they mark more than females. In both sexes, scent gland activity is dependent on gonadal hormones. Observations on colonies of gerbils, living in enclosures or cages, showed that both scent gland size and marking behaviour were related to social status. In colonies founded by a single pair, breeding was confined to the original female. The infertility of the daughters was due to failure of sexual maturation. As this was always associated with a lack of development of the scent glands, the functional state of the latter could be used as an index of fecundity. A change in social organization (eg removal of the parents) caused previously infertile females to conceive and was accompanied by development of the scent glands If there was competition for dominance, the scent glands of the losers regressed; at autopsy, their ovaries and uteri appeared to be nonfunctional. The founding father usually had a larger scent gland than his sons, but the inhibition of sexual function was not as severe as in the females. However, the father characteristically showed much more marking behaviow in a neutral territory than his sons. None of the fem ales-except the mother-showed appreciable marking, and her scores were much lower than those of the dominant male. Asymptotic populations were reached at about the same level in enclosures and cages, implicating an intrinsic capacity for control independent of the number of animals per unit of space but probably related to the natural size of a social group. Stabilization of numbers was achieved not only by reproductive inhibition of young females, but also by cessation of breeding by the founding mother and death of litters. Littermates raised in enclosures without their parents showed delayed sexual maturation accompanied by fighting which resulted in the formation of a hierarchy headed by a breeding female and a dominant (marking) male.     

Sex differences in aggressive behaviour in various strains of mice

Two nonalbino inbred (C57 BL/6 and C3H/He) and one albino strain (Swiss) of mice were compared for female aggression toward intruders: 1 in period of lactation, 2 in nonlactating state and (3) in nonlactating state but previously rubbed with urine of lactating females; and for male aggression toward familiar or unfamiliar opponents. The results showed that resident females of the C57 and Swiss strain vigorously attack lactating intruders introduced into their cages. This effect was mediated by urinary cues emitted by the latter mice. It was also shown that Swiss residents displayed aggression towards nonlactating females, irrespective of their strain. Groups of C57 residents reacted most aggressively towards Swiss females, less aggressively towards C3H intruders, but did not show any aggression towards their own nonlactating conspecifics. In contrast, none of the C3H resident female groups displayed aggression towards intruding females of any category or strain. The results also showed that the males of the three strains displayed little (Swiss and C3H) or no aggression (C57) towards familiar opponents, whereas they directed increased aggressive responses towards unfamiliar ones. Comparisons among the three strains of mice revealed that Swiss males were the most aggressive in either situation. On the other hand, the finding that C3H males showed aggressive responses suggested that male and female aggression are, in this strain, under separate genetic or hormonal control.     

Growth and social behavior of previously undernourished mice

Developing mice were growth-retarded by underfeeding of their mothers during lactation. Control mothers were well nourished throughout. All offspring were fed ad libitum from weaning till their behaviour was tested in adulthood. The undernourished mice had weight deficits at weaning of 49% compared with controls. Nevertheless, they showed partial catch-up growth thereafter, in that their absolute weight deficits decreased between weaning and adulthood. Social behaviour observations were made on pairs of mice of the same treatment group. Previously undernourished mice were slower to start attacking one another, spent more time near or in contact with one another and did less tail-rattling than their controls.     

小规模群体开放式与封闭式讨论任务的工作特性比较

１４个小组的大学生共６８人参加两种不同的群体工作,其中７组进行开放式问题的讨论,７组进行封闭式问题的讨论。从工作进程、工作模式和工作特点等方面记录群体工作行为：工作进程各阶段所用时间,发言的针对性,发言的连续性,说明问题的方式和深度,群体的意见分歧与支持行为和表达方式。结果表明：封闭式问题需要更多的时间澄清问题并且更多引用例子来阐述观点;讨论开放式问题多采用归纳推理而封闭式问题多采用演绎推理;无论在哪种问题的讨论中,针对个体的发言都显著多于针对整体的发言,而且人们更多地以非言语的方式而不是口头方式表示赞成。本文对以上结果在电视、电话和计算机辅助会议系统设计中的应用作了进一步讨论     

Peer networks and bullying in schools

This study looked at how the social constellations in school classes relate to bullying problems. Using peer-evaluation questionnaires, the peer networks of children with different participant roles (such as victim, bully, assistant of bully, reinforcer of bully, defender of victim, outsider) were explored. The subjects were 459 sixth-grade-children (218 girls, 241 boys), aged 11 to 12 years, in Finland. The main findings were: 1) Children who tended to behave in either similar or complementary participant roles in situations of bullying formed networks with each other. The individual child's behavior in bullying situations was strongly connected to how the members of his/her network behaved in such situations. 2) Bullies, assistants, and reinforcers belonged to larger networks than did defenders, outsiders and victims. 3) Children outside the networks were most often victims. It was concluded that behavior in bullying situations can be said to be one feature around which the peer networks in school classes are organized. Thus prevention, as well as intervention strategies against bullying should focus not only on individual children, but also on the wider social context of the class.