REVIEW Maternal influences on primate social development Dario Maestripieri 1 Received: 17 January 2018 /Revised: 4 July 2018 /Accepted: 7 July 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Primate mothers have the potential to influence the development of species-typical aspects of their offspring’ s behavior as well as their individual sociosexual and reproductive strategies. If mothers experience psychosocial stress during pregnancy or lactation, their own stress hormones can have a long-term impact on their offspring’ s physiology. The mother’ s own behavior, especially weaning-related rejection, can be stressful to infants and have long-lasting effects on their infants’ neuroendocrine reactivity to stress. Exposure to variable maternal style early in life has long-term effects on the development of offspring behavior, including exploration and play, affiliation and aggression, and parenting. Primate mothers influence the kinship- and rank-related social preferences of their offspring, typically by providing opportunities to interact with some individuals more than others. Although mothers can contribute to the development of sex-typical behavior in the offspring (along with other environmental and genetic factors), sex-typical behavior is generally not the product of maternal socialization. Mothers provide their offspring with oppor- tunities for social learning but rarely teach their infants new skills. In primate species with despotic dominance hierarchies, maternal transmission of rank through agonistic aid to their offspring makes a crucial contribution to the offspring’ s fitness (as the daughters of high-ranking mothers reproduce more successfully than the daughters of low-ranking mothers). Future studies of maternal influences on social development could benefit from a deeper theoretical and experimental investigation of the evolu- tionary significance of these effects as well as of their underlying proximate mechanisms. Keywords Maternal effects . Social development . Stress reactivity . Sex differences . Social learning . Primates Introduction In nonhuman primates, mothers bear most (and in many cases, all) of the burden of childrearing across a wide range of parental activities (nutrition, transport, protection, social support, educa- tion) and for almost their entire lifespan, as maternal investment often continues into adulthood. Significant paternal investment is extremely rare and limited to highly specific socioecological and reproductive contexts: for example, in marmosets and tamarins, fathers Bare forced^ to carry their offspring because females give birth to twins and incur significant energetic constraints (Clutton- Brock 1991). Help in raising offspring from older siblings, other relatives, and unrelated adults is also rare (Maestripieri 1994). Primate mothers establish intimate physiological connec- tions with their offspring from the day of conception until their offspring are weaned from breast milk (a period of time that can last several years) as well as strong socio-emotional bonds from the birth of the offspring (or even earlier) through the last day of their own life. Primate mothers, therefore, have the potential to influence virtually any aspect of their offspring’ s phenotype through a variety of different mechanisms: genetic, nutritional, hormonal, immunological, emotional, cognitive, social, and environmental (Maestripieri 2009). Mothers can even influence their offspring’ s reproductive decisions and their investment in their own descendants for several subse- quent generations (Maestripieri 2009). Many maternal influences on offspring development con- cern basic aspects of their survival or their growth; this is the case for effects that occur through maternal nutrition of the offspring or through the transfer of immunological substances to them through the placenta or breast milk. However, there is a lot more to fitness in primates than nutrition and growth. For example, in most species of primates, and especially in humans, social success is a crucial component of reproductive success, as making friends and allies, achieving high status, This article is a contribution to the Topical Collection An evolutionary perspective on the development of primate sociality – Guest Editors: Federica Amici and Anja Widdig * Dario Maestripieri dario@uchicago.edu 1 Department of Comparative Human Development, The University of Chicago, 940 E. 57th street, Chicago, IL 60637, USA Behavioral Ecology and Sociobiology (2018) 72:130 https://doi.org/10.1007/s00265-018-2547-x