Changes in relationships of nulliparous and parous females of Japanese monkeys at arashiyama with some aspects of troop organization

Social interactions of the adult females (nulliparous, primiparous, multiparous young, and multiparous old) of the Arashiyama-B troop of Japanese monkeys were studied. Using focal-animal and instantaneous sampling techniques, specifically identified social interactions involving allogrooming, social play, and agonism, nonspecific body-contact with and proximity to other animals were recorded from 1975 to 1978. By identifying the animals who had the above mentioned social interactions with the focal females, an attempt has been made to analyze the changes in relationships between the females of different classes and their closest kins, distant kins, and non-kins. Multiparous young females spend more time in social interactions involving allogrooming, nonspecific body-contact, and proximity than do females of the other classes and most of their social interactions are centered around their own offspring. Social interactions of the nulliparous females are fewer than those of the young mothers. But, the social interactions of the nulliparous females with their kins are much more frequent than those of the other females, i.e., once a female bears offspring, she concentrates her efforts in raising it and her social life becomes closed than before. Social interactions of the old mothers decrease and their social life is also centered more around their own young offspring. However, the social interactions of the females with non-kins, the interactions which strengthen troop integration, are independent of the class of the females. This report constitutes one part of the thesis submitted by the author to the Faculty of Science of Kyoto University in 1979 for the award of degree of Doctor of Science.     

Female dominance and female social relationships among yellow baboons (Papio hamadryas cynocephalus)

Adult females in a female-bonded, cercopithecine species such as baboons are characterized by hierarchically ranked matrilines, i.e., female offspring assume rankings just beneath those of their mothers. In this system of closely ranked matrilines, a female should engage in significantly more affiliative interactions with those individuals who are closely ranked to herself than with those individuals who are more distantly ranked. We examine the hypothesis that females in this troop of feral yellow baboons (Papio hamadryas cynocephalus) who are closely ranked will also show close social affiliation. We collected focal data on 23 feral, adult female subjects (253 possible dyads) over approximately 1 year at the Tana River National Primate Reserve, Kenya. Following Bramblett's [Behav Brain Sci 4: 435, 1981] method of dominance tabulation and utilizing a modified version of Smuts' [Sex and friendship in baboons, Hawthorne: Aldine Publishing Co., 1985] preferred partner index, we describe and compare the dominance matrix and hierarchy, preferred proximity partner and grooming partner sociograms, and the social networks of these 23 focal females. Over 1,400 interactions were utilized in the dominance tabulations, 41 statistically significant proximity partner preferences were documented, and 100 grooming dyads were recorded. We examine both partners' ranks and the presence of an infant as possible factors influencing proximity and grooming partner preferences. We find that in this population there is no direct correspondence between females' ranks and their affiliation partners. Neither proximity nor grooming preferences are consistently predictable from partners' ranks. While proximity preferences were not significantly influenced by the presence of an infant, grooming partner preferences were. Females with infants had more grooming partners and were more often involved in unidirectional grooming relationships as the recipients than were females without infants. We conclude that females' dominance rankings are not good predictors of either proximity partner or grooming partner preferences and that the presence of an infant does have a significant impact on grooming partner preferences in this population.     

Birth-season interactions of adult female Japanese Macaques(Macaca fuscata) without newborn infants

The affiliative interactions of 11 adult female Japanese macaques that did not deliver an infant during the 1981 birth season of the Arashiyama West troop were examined. Consideration was given to the effects of kinship as a structuring element in these birth-season interactions and to the degree of association with various categories of troop members based on age, sex, and (in the case of adult females) whether or not the females were new mothers. Females without infants interacted predominantly with their yearling off-spring, although it was the behavior of the offspring that precipitated the interaction. These females were active in soliciting affiliation with nonkin new mothers, whereas female matrilineal relatives with new infants approached and remained in proximity to them more than did nonrelated new mothers. Females without newborns groomed and approached nonkin infants more than infants within their own matriline, and these infants were predominantly those of females in the highest-ranking matriline of the troop. Adult males were responsible for 40% of all grooming received from nonkin by the females without newborns, and these males approached them significantly more than did other adult females without infants. These patterns demonstrate that the structure of social relationships is influenced by the particular dynamics of troop contexts such as birth seasons, as well as by enduring, broad-based affinities which are less affected by cyclic changes in troop context.     

Long-term grooming partnerships between unrelated adult females in a free-ranging group of Japanese monkeys (Macaca fuscata)

In order to examine the presence of long-term grooming relationships among unrelated females, grooming interactions of 18 adult females (range: 16-32 years) in a free-ranging group of Japanese monkeys (Macaca fuscata) were recorded in 2003 and compared with those recorded 10 years earlier, i.e., in 1993. In 2003, on average, each female who had survived the 10 years had grooming interactions with 2.2 surviving old partners with whom she was recorded to have grooming interactions in 1993, 3.5 females related to the surviving old partners, and 4.5 unrelated females who were other than the surviving old partners or their related females. By calculating the ratio of actual grooming partners to available females in 2003, we concluded that females had a greater possibility of selecting surviving old partners as their grooming partners than other unrelated partners, and that they also had a greater possibility of selecting females related to surviving old partners than females other than surviving old partners and their related females. These findings indicate that with regard to grooming relationships, female Japanese monkeys are basically conservative, showing a tendency to concentrate their grooming interactions on closely related females and certain familiar unrelated females such as surviving old partners and some females closely related to these partners. At the same time, however, female Japanese monkeys also showed a progressive trait for grooming since they formed grooming relationships with new partners. The necessity of long-term psychological bonding for long-term grooming relationships between unrelated females is discussed in this work.     

Grooming relationships of adolescent orphans in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama: a comparison among orphans with sisters, orphans without sisters, and females with a surviving mother

The present study examined grooming relationships of adolescent females in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama. To assess whether the loss of the mother influenced the grooming relationships of adolescent females (5–7 years old), we compared the time spent in grooming interactions and the number of grooming partners among the following three groups: 6 adolescent orphans with sisters, 9 adolescent orphans without sisters, and 11 adolescent non-orphans with surviving mothers. In Japanese macaques, grooming most frequently occurs between mothers and their daughters. Therefore, it is expected that if the mother is lost, orphans will devote less time to grooming interactions than non-orphans. However, the time spent in overall grooming interactions did not differ among the three groups. While non-orphans maintained grooming relationships with their mothers, orphans acquired alternative grooming relationships with other group members. Orphans adopted two kinds of tactics to compensate for the loss of the mother. First, adolescent orphans with sisters developed more affiliative grooming relationships with their sisters than non-orphans with sisters. Secondly, adolescent orphans without sisters spent more time in grooming interactions with same-aged females and non-related adult females. Moreover, regarding grooming interactions with same-aged females and non-related adult females, orphans without sisters had a larger number of grooming partners than non-orphans. These results indicate that adolescent females have enough flexibility to develop their grooming network after the loss of their mothers, and that the lack of mother and sisters might accelerate socialization of adolescent females and enable them to be integrated in reciprocal adult grooming relationships.     

Social Relationships Among Ring-Tailed Lemurs (Lemur catta) in Two Free-Ranging Troops at Berenty Reserve, Madagascar

We observed two free-ranging troops of ring-tailed lemurs at the Berenty Reserve, Madagascar. Kinship affinities in these troops are known only for mothers and their offspring 4 years of age. We attempted to quantify social relationships. Almost all agonistic interactions were dyadic, and triadic agonistic interactions, such as alliances, were very rare. Dominance hierarchies in both sexes in the two troops were not linear. As in cercopithecine monkeys, mothers were dominant over their adult daughters. However, the daughters were not ranked immediately below their mothers. Close proximity and social grooming occurred more frequently between closely related females, such as mother–daughter and sister–sister dyads, than between unrelated females. Frequent-proximity relations also occurred between adult males that had emigrated from another troop and entered the present troop together, even though they did not rank closely to one another. Subordinates were likely to groom and to greet dominants more frequently than vice versa. During group encounters, particular females were involved in agonistic interactions with animals of other troops, regardless of dominance rank. Adult males, regardless of their dominance rank, but not adult females, constantly tried to drive solitary males away.     

Aggression, grooming and group-level cooperation in white-faced capuchins (Cebus capucinus): insights from social networks

The form of animal social systems depends on the nature of agonistic and affiliative interactions. Social network theory provides tools for characterizing social structure that go beyond simple dyadic interactions and consider the group as a whole. We show three groups of capuchin monkeys from Barro Colorado Island, Panama, where there are strong connections between key aspects of aggression, grooming, and proximity networks, and, at least among females, those who incur risk to defend their group have particular "social personalities." Although there is no significant correlation for any of the network measures between giving and receiving aggression, suggesting that dominance relationships do not follow a simple hierarchy, strong correlations emerge for many measures between the aggression and grooming networks. At the local, but not global, scale, receiving aggression and giving grooming are strongly linked in all groups. Proximity shows no correlation with aggression at either the local or the global scale, suggesting that individuals neither seek out nor avoid aggressors. Yet, grooming has a global but not local connection to proximity. Extensive groomers who tend to direct their efforts at other extensive groomers also spend time in close proximity to many other individuals. These results indicate the important role that prosociality plays in shaping female social relationships. We also show that females who receive the least aggression, and thus pay low costs for group living, are most likely to participate in group defense. No consistent "social personality" traits characterize the males who invest in group defense.     

Adolescent male chimpanzees (Pan troglodytes) form social bonds with their brothers and others during the transition to adulthood

Social relationships play an important role in animal behavior. Bonds with kin provide indirect fitness benefits, and those with nonkin may furnish direct benefits. Adult male chimpanzees (Pan troglodytes) exhibit social bonds with maternal brothers as well as unrelated adult males, facilitating cooperative behavior, but it is unclear when these bonds develop. Prior studies suggest that social bonds emerge during adolescence. Alternatively, bonds may develop during adulthood when male chimpanzees can gain fitness benefits through alliances used to compete for dominance status. To investigate these possibilities and to determine who formed bonds, we studied the social relationships of adolescent and young adult male chimpanzees (N = 18) at Ngogo in Kibale National Park, Uganda. Adolescent male chimpanzees displayed social bonds with other males, and they did so as often as did young adult males. Adolescent and young adult males frequently joined subgroups with old males. They spent time in proximity to and grooming with old males, although they also did so with their age peers. Controlling for age and age difference, males formed strong association and proximity relationships with their maternal brothers and grooming relationships with their fathers. Grooming bonds between chimpanzee fathers and their adolescent and young adult sons have not been documented before and are unexpected because female chimpanzees mate with multiple males. How fathers recognize their sons and vice versa remains unclear but may be due to familiarity created by relationships earlier in development.     

Sexually dimorphic transitions revealed in the relationships of yearling rhesus monkeys following the birth of siblings

We report here that in a large captive group of monkeys, Macaca mulatta,sudden sex-related changes occur in social interactions in one short phase of an infant’s development. Social interactions of 1-year-old animals (males, N =12; females, N =8) 6 weeks before the birth of siblings were compared with interactions occurring 6 weeks after the birth. On the day of the siblings’ birth, depression-like postures were seen in two yearling males (YMs); 10 YMs showed hyperactivity. In the postbirth period, YMs refocused their attentions away from their mother and toward other, often unrelated members of the group. Although YMs initiated disengagement of interactions with their mothers, there was evidence that mothers attempted to lessen this disengagement. The YMs had close relationships with specific (“preferred”) male individuals. These relationships (particularly those with adult males) became more pronounced following the birth of the sibling. The adult-male group also took an active role in maintaining interactions with YMs. The preferred partners in the YM-other male relationship before the birth of the sibling were, however, not always the same as those in the period after the birth. Dominance relationships and probably genetic factors determined patterns of interaction between YMs and their preferred male partners. Among yearling females (YFs), no dramatic changes in interactions with their mothers or with other group members were detected after their mothers gave birth. Relationships in YF-mother and YF-other-individual pairs (especially when the other individual was kin) seemed to be consolidated during the postbirth interval. There was little evidence of jealousy between the YFs and their younger siblings. Thus, sibling birth acted as a stimulus for the occurrence of sexually dimorphic interactions in yearlings. We suggest that in natural environments, social interactions in YFs promote relationships that will serve to integrate them into the matrilineal social structure, whereas comparable behavior in YMs encourages relationships with males that they may emigrate with into, or meet again in, nonnatal troops.     

Social structures in Pan paniscus: testing the female bonding hypothesis

Based on previous research in captivity, bonobos, Pan paniscus, have been called a female-bonded species. However, genetic and behavioural data indicate that wild females migrate. Bonding between these unrelated females would then be in contradiction with socio-ecological models. It has been argued that female bonding has been overemphasized in captive bonobos. We examine patterns of proximity, grooming and support behaviour in six well established captive groups of bonobos. We find that female bonding was not a typical characteristic of all captive bonobo groups. In only two groups there was a trend for females to prefer proximity with other females over association with males. We found no evidence that following or grooming between females was more frequent than between males and unrelated females or between males. Only in coalitions, females supported each other more than male–female or male–male dyads. We also investigated five mother–son pairs. Grooming was more frequent among mothers and sons than in any other dyad, but sons did not groom their mothers more than males groomed unrelated females. Mothers groomed their sons, or provided more support to them than females groomed or supported unrelated males. Thus, while bonds between females were clearly present, intersexual relations between males and either unrelated females or their mothers are of more, or equal importance.     

Grooming interactions among adult chimpanzees at Bossou,Guinea, with special reference to social structure

Grooming and proximity interactions among chimpanzees at Bossou, Republic of Guinea, were analyzed as an index of friendly and affinitive relationships among adult males, among adult females, and between the sexes. Data from the first (1976–1977) and the third (1982–1983) study period were used. The expected value of their interactions was calculated from the number of adult males and females in the group and also from the observed frequency of combinations of adult males and females in the parties (temporary foraging groups). In the pooled data from the two periods, there was little difference between grooming and proximity (without grooming). The frequency of male-female grooming and proximity interactions was lower than expected, and that of female-female interactions was higher than expected. The frequencies of male-male grooming and proximity were intermediate but fluctuated. Male-male grooming frequency was lower than that recorded in chimpanzees of East Africa. Characteristics of same-sex affinitive interactions, especially between Bossou chimpanzee females, clearly differ from those of East African chimpanzees and are more like those recorded for female-related groups of Japanese macaques (Macaca fuscata).These differences indicate the variability and flexibility of chimpanzee social structure.     

Social behaviour and infant carrying in a group of moustached tamarins,Saguinus mystax (primates: Platyrrhini: Callitrichidae), on Padre Isla,Peruvian Amazonia

The social behaviour of a group of eight moustached tamarins,Saguinus mystax, (five males, three females) was studied on Padre Isla in northeastern Peru. About 60% of all allogrooming was done by the two adult males in the group, and about 11% by a young adult female. All other group members groomed very little. The adult breeding female received more grooming than any other group member. After the death of the adult female (preyed upon by an anaconda) the amount of active allogrooming remained constant for all group members except for the young adult female, who increased her contribution to about 30%. Her preferred grooming partner was the subadult female, which generally screamed when being groomed by the young adult female and terminated grooming by going away. This kind of grooming relation is termed “forced grooming” and is interpreted as a possible social control mechanism. The young adult female groomed the adult males more often after the death of the adult female than before. This might have had the function of strengthening the social bond with the adult males and in obtaining the breeding position in the group. After the death of the adult female, the vulva of the young adult female grew to full adult size. Agonistic behaviour was less frequent than allogrooming. Most aggressive interactions (50%) originated from the subadult male of the group. The young adult female was the target of most of these aggressions. Extremely little aggression occurred between the three females. The young adult female was the only individual who tried to emigrate from the group during the study period. Her attempt to join a neighbour group failed due to rejection by all four members of this group. All group members participated in carrying an infant, but the adult males and the young adult female carried most frequently. Contribution to infant carrying varied with the infant's age.     

Proximity association in polygynous western black crested gibbons (Nomascus concolor jingdongensis): network structure and seasonality

We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally and was affected by temperature and rainfall. Preferred proximity association was not distributed randomly among individuals. Kinship was one explanation for the social structure, as offspring preferred to maintain close proximity with their mothers. The proximity of infants to mothers decreased with age, and independent offspring had lower proximity to mothers than dependent ones. We found that the adult male had different proximity relationships with two different adult females. The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group. Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences. Temperature influenced group proximity association, with individual proximity increasing in the cold months and decreasing in the hot months. Group proximity decreased in months with higher anthropogenic disturbance.     

Proximity and grooming patterns reveal opposite-sex bonding in Rwenzori Angolan colobus monkeys (<Emphasis Type="Italic">Colobus angolensis ruwenzorii</Emphasis>)

Close proximity and social grooming are important bonding mechanisms in primates. These behaviors show the social structure of a species and many studies have found positive correlations between the degree of kinship and grooming and proximity. We used 1 year of data collected via instantaneous scan sampling on a large “supertroop” of Colobus angolensis ruwenzorii at Lake Nabugabo, Uganda, to examine partner preferences for grooming and nearest neighbors in each age-sex class. Little is known about this species, so we based our hypotheses on congeners. Of the five species of black-and-white colobus, data on sex-biased dispersal patterns are available for three (C. guereza, C. vellerosus, and C. polykomos), all of which show male-biased dispersal with occasional female dispersal. We thus predicted that female C. a. ruwenzorii would be more strongly bonded than males, showing greater proximity and grooming. We did not expect bonding between the sexes since congeners do not show this pattern. We found that among adult dyads, males and females were more likely to be found in loose proximity, and to groom, than would be expected given group composition. Conversely, both males and females had relatively weak same-sex relationships. Between the sexes, adult males had higher proximity and grooming indices with adult females without infants than with females with infants. These observations indicate that this subspecies is cross-bonded and that both sexes may disperse. Furthermore, our findings suggest that the social organization and social structure of C. a. ruwenzorii differ greatly from other black-and-white colobus species.     

Affiliative relationships and reciprocity among adult male bonnet macaques (Macaca radiata) at Arunachala Hill, India

In captivity, male bonnet macaques (Macaca radiata) frequently express "friendship" toward one another, including affiliative behavior such as huddling, grooming, coalitionary support, and sitting in close proximity. The purpose of this study was to determine whether wild adult male bonnet macaques also express "friendship" by investigating whether or not (1) adult male bonnet macaques have affiliative social relationships with other males, (2) the strength of social relationships varies among dyads, (3) there is time-matched reciprocity in allogrooming among dyads, and if so, whether the level of reciprocity occurs within a bout of grooming, a day, or over 2 months (the limit of this study), and (4) a correlation exists between the strength of social relationships and dominance ranks among adult males. Focal samples totaling 150 hr on all seven adult males in one study group were conducted to record both agonistic and affiliative interactions. Agonistic interactions were used to construct a dominance hierarchy, whereas affiliative interactions (sitting in proximity to within 1 m with and without grooming) were used to quantify the existence and strength of social bonds within dyads. Results show that adult male bonnet macaques had differentiated affiliative relationships with other males in their group. There was little reciprocity of grooming within a bout of grooming or within a day, but greater reciprocity over the study period of 2 months. There was no correlation between dominance ranking distance and the strength of affiliative relationship within dyads; however, within dyads lower-ranking males groomed higher-ranking males more than vice versa. This study suggests that friendships in male bonnet macaques are characterized not by immediate tit-for-tat reciprocal altruism, but by reciprocity over a longer time span, and that affiliative social relationships may be less constrained by agonistic relationships than is the case in more despotic species of macaques.     

The social grooming of captive female rhesus monkeys: Effects of the births of their infants

We observed the grooming interactions of 13 female rhesus monkeys (Macaca mulatta)before and for 12 weeks after the births of their infants. Mothers groomed for similar amounts of time before and after the birth of their infants, but after the birth, the grooming they directed to their infants may have been at the expense of that directed to other partners. Lactating females did not receive more grooming from other females but were approached more often, suggesting that they were more attractive. Mothers that groomed their infants most groomed others least, as if grooming time was limited for each mother or as if she was trying to compensate for avoiding interactions with other partners. Mothers of male infants groomed others more than mothers with female infants did, which might be due to mothers with daughters receiving more aggression and therefore avoiding interaction. Experienced and high-ranking mothers groomed their newborn infants considerably more than primiparous mothers did in the 24 hr following birth. Grooming was preferentially directed at close kin before the births of the infants. Mothers tended to groom higher-ranked partners more than they were groomed by them, and they tended to receive more grooming from lower-ranked partners than they gave, as suggested in models of rank attractiveness.     

Social relationships between adult male and female rhesus macaques: II. non-sexual affiliative behaviour

The social relationships of adult male rhesus macaques (Macaca mulatta) in Group I of the Cayo Santiago colony were studied over a period of 14 months. Relationships were found in which adult males and sexually mature females were persistently close to one another in nonsexual contexts, both within and across seasons. Males of long tenure and high dominance rank tended to have more female partners, and more persistent relationships, than more recent immigrants of lower rank. Correlations with length of tenure were stronger than those with dominance rank. Closely-related females tended to have persistent relationships with the same male. In most cases the female was primarily responsible for maintaining proximity in non-sexual contexts. Dyads which were persistently within 5 m of each other in the birth season were more likely to form a consortship in the subsequent mating season than those which had a brief relationship. A similar tendency was apparent in the 1 m data but it was not statistically significant. There was no association between persistent proximity during the birth season and the occurrence of long, or multiple consortships, nor with the maintenance of proximity or direction of grooming between consort partners. The pattern of consortships was not closely related to the formation of persistent relationships in the subsequent birth season. Females occasionally received protection from their male partners and, in some cases, spent more time in the feeding corral with them than did other females. Affiliative relationships can be very enduring and may have long-term benefits that were not apparent during the study period.     

Social relationships between adult females and the alpha male in wild tufted capuchin monkeys

Primates are notable for the widespread presence of long-term female-male associations which go beyond the mating context. However, little attention has been given to the factors that affect within-species variation in female-male relationships, especially among New World primates. Although detailed accounts of heterosexual relationships in Cebus species are scarce, a few studies have suggested the occurrence of strong associations between adult females and high-ranking males. This study explores affiliative relationships between females and the alpha male during the nonbreeding season in wild tufted capuchin monkeys (Cebus apella nigritus). Affiliative relationships were explored through female-male patterns of spatial proximity and grooming. By adopting a social network approach, we analyzed: (1) whether the alpha male is the preferred male partner for females and, (2) whether variation (if any) in female-alpha male affiliation can be explained through both female individual characteristics and social network metrics. Our results showed that alpha males were the favorite male partner for adult females in the proximity networks, but this did not hold true in the grooming networks. In addition, female-alpha male interaction patterns showed considerable variation, with only some females being strongly associated with the alpha male. Our results suggest that such a variation can be explained by female dominance rank, level of centrality (the quantity and intensity of spatial connection with other females) and prestige (the quantity of grooming received by other females) in female-female social networks. Taken together, these findings highlight two aspects of female-alpha male relationships in tufted capuchin monkeys: the alpha male represents the most socially integrated male in the group, and females with high dominance ranks and high centrality in both proximity and grooming networks show stronger relationships with the alpha male.     

Social behavior of infant and mother Japanese Macaques (Macaca fuscata): Effects of kinship,partner sex,and infant sex

The behavioral interactions of 22 infant and mother Japanese macaques with other group members were studied. Focal-animal observations were made from the time of each infant’s birth until 1 year of age. Infants and mothers both displayed exceedingly strong preferences for associating with matrilineal kin and, specifically, for female kin. The degree of genetic relatedness was positively correlated with levels of spatial proximity, contact, grooming, aggression, and play. Overall frequencies of interactions with nonkin were very low, and partner sex was not an important factor in interactions with nonkin. There were no significant differences between male and female infants in interactions with kin versus nonkin. There was only one significant difference between male and female infants in interactions with males versus females: female infants showed stronger preferences for initiating proximity with females over males than did male infants. Because mothers provide the focal point for infant interactions during the first year of life, we compared the behavior of infants and mothers. Mothers were the recipients of more social interactions than were infants, mothers engaged in more grooming than did infants, and infants engaged in more social play than did mothers. These findings are only partially consistent with kin-selection theory, and the inadequacies of studying matrilineal kin discrimination to test kin selection are reviewed. The near-absence of infant sex differences in associations with social partners suggests that although maternal kin other than the mother are important to infant socialization, they probably do not contribute to the development of behavioral sex differences until after the first year of life.     

Interplay between various aspects in social relationships of young rhesus monkeys: Dominance,agonistic help,and affiliation

Relationships between group-living primates depend strongly on their position in the group dominance hierarchy and on their relationships with other group members. The influence of various behaviours on social relationships of immature rhesus monkeys (Macaca mulatta) was investigated here. Dominance ranks were established and related to the degree of affiliation in a dyad. Older monkeys were mostly dominant to the younger ones, regardless of kinship. Subordinate monkeys left proximity of their dominant members more often than they were left by them both among siblings and non-siblings, but the effect of dominance rank on the amount of play initiation and grooming in a dyad differed between these two types of dyads. The amount of agonistic help two individuals provided for each other was low among immatures. Nevertheless, pairs of siblings gave help to each other in agonistic conflicts more often than non-siblings, and such help was more often reciprocated between siblings than between non-siblings. Help in agonistic conflicts was positively correlated with the amount of time monkeys spent playing, grooming, or in proximity. Adults tended to interfere less in conflicts of frequent sibling play partners or non-sibling grooming partners. No evidence was found for young monkeys to exchange reciprocally grooming for agonistic help. It is argued that the time monkeys spend interacting with each other in affiliative interactions increases their familiarity and thus promotes close relationships between them. On the whole, young monkeys' relationships, like those between adults, are influenced strongly by their kinship, and position in the dominance hierarchy.