Mothers make a difference: Mothers develop weaker bonds with immature sons than daughters

Among mammals, individuals form strong social bonds preferentially with their kin. Differences in these relationships are linked to differential kin availability due to sex-specific dispersal patterns, but there is some indication that differential bonding among sexes already occurs prior to maturation. However, little is known about how these patterns arise during individual development. Here we investigated sex differences in the development of mother-offspring bonds in rhesus macaques (Macaca mulatta). Our results revealed that mothers showed sex-biased bonding toward their offspring. Sons had a distinctly higher probability of receiving aggression from their mothers than did daughters in the first year of life, while no differences were found with respect to affiliative interactions. After the first year, probabilities of all affiliative and aggressive behaviours investigated were higher for daughters than for sons, although generally declining. Furthermore, sons spending less time with their mother and receiving more maternal aggression tended to disperse earlier. The results of our study suggest that mothers influence their bonding strength with offspring by interacting less affiliative with sons than daughters

Mother-male bond, but not paternity, influences male-infant affiliation in wild crested macaques

In promiscuous primates, interactions between adult males and infants have rarely been investigated. However, recent evidence suggests that male affiliation towards infants has an influence on several aspects of the infants’ life. Furthermore, affiliations may be associated with male reproductive strategy. In this study, we examined which social factors influenced male-infant affiliation initiated by either male or infant, in wild crested macaques (Macaca nigra). We combined behavioral data and genetic paternity analysis from 30 infants living in three wild groups in Tangkoko Reserve, Indonesia. Our results indicate that adult males and infants do not interact at random, but rather form preferential associations. The social factors with the highest influence on infant-initiated interactions were male rank and male association with the infant’s mother. While infants initiated affiliations with males more often in the absence of their mothers, adult males initiated more affiliations with infants when their mothers were present. Furthermore, males initiated affiliations more often when they were in the same group at the time the infant was conceived, when they held a high dominance rank or when they had a close relationship with the mother. Interestingly, paternity did not affect male-infant affiliation despite being highly skewed in this species. Overall, our results suggest that adult males potentially associate with an infant to secure future mating with the mother. Infants are more likely to associate with a male to receive better support, suggesting a strategy to increase the chance of infant survival in a primate society with high infant mortality

Growing into adulthood – a review on sex differences in the development of sociality across macaques

Preferential affiliative relationships, or social bonds, play a crucial role in primate social life, but little is known about their development. Here, we review macaque studies investigating the social development of both sexes. Firstly, we highlight the emergence of sex differences in mother–offspring bonds, as macaque mothers form stronger bonds with daughters, while being more aggressive towards sons, possibly contributing to maintain female philopatry and/or male dispersal. Secondly, despite paternity uncertainty, we discuss studies reporting that fathers of several macaque species preferentially engage with their offspring, but less than mothers and only in periods of high infant mortality. Thirdly, we show that immature females, the philopatric sex in macaques, already form stronger bonds with close maternal kin than immature males, mirroring social patterns during adulthood. However, this bias seems not caused by kin availability, as kin availability is similar for both sexes prior to male dispersal. Moreover, immature males might preferentially affiliate with paternal kin over non-kin, possibly because of lower maternal integration in their maternal family and/or in preparation of dispersal. Fourthly, we discuss how immature females engage in grooming and proximity with female partners as they grow older, while immature males preferentially interact with adult males and peers, playing more than females from early on. Finally, we show that most developmental changes in sociality happen around 2–3 years of age, probably representing a milestone in macaque social development. We conclude that sex differences in sociality emerge early in development and increase through time, with sexes gradually growing into their adult roles

Sex differences in the development of social relationships in rhesus macaques (Macaca mulatta)

Several studies have documented the importance of social bonding for the enhancement of individual fitness. However, little is known about how social relationships develop through ontogeny, and whether their development follows the same trajectory in males and females. Here we analyzed affiliative interactions (proximity, social grooming, play) combined with demographic and genetic data in semi-free-ranging rhesus macaques (Macaca mulatta) on Cayo Santiago over their first 4 yr of life (from birth to sexual maturation) to understand how these interactions change through development in both sexes. Generalized linear mixed models revealed that social behaviors mostly followed different developmental trajectories in males and females and were highly dependent on the social context. In particular, sex differences in social behavior varied through development depending on the partner’s sex and age. Females engaged in more social interactions than males, especially with other females, and were more involved in grooming around the time of maturation. In contrast, males interacted more with males and age peers, especially around maturation. Sex differences in social behavior varied through development, but also depended on rank, partner’s rank, and kin line, although not consistently. High-ranking individuals, especially older females, were generally preferred as social partners. Moreover, both male and female individuals interacted mostly with maternal kin, although males also preferred paternal kin over nonkin. Importantly, most developmental changes in sociality happened when individuals were ca. 2 yr old, suggesting that this might be a milestone in the development of sociality in rhesus macaques. The only notable exception to this pattern was play, which was more pronounced in males from the beginning of their lives. We propose that play might serve as a trigger of sex differences in social behavior, with sex differences emerging early in development and increasing through time as males and females gradually grow into their adult social roles

Privacy-Preserving Abuse Detection in Future Decentralised Online Social Networks

International audienceFuture online social networks need to not only protect sensitive data of their users, but also protect them from abusive behavior coming from malicious participants in the network. We investigate the use of supervised learning techniques to detect abusive behavior and describe privacy-preserving protocols to compute the feature set required by abuse classification algorithms in a secure and privacy-preserving way. While our method is not yet fully resilient against a strong adaptive adversary, our evaluation suggests that it will be useful to detect abusive behavior with a minimal impact on privacy