Adoption and maltreatment of foster infants by rhesus macaque abusive mothers

Abstract

In this study we investigated whether infant characteristics play a causal role in the occurrence of maternal abuse of offspring in rhesus macaques (Macaca mulatta) and whether abusive mothers differ from controls in their tendency to adopt alien infants in a cross-fostering procedure. To this end, 13 infants born to mothers with a previous history of infant abuse were cross-fostered shortly after birth with infants born to nonabusive mothers and subsequently observed for 12 weeks. Abusive mothers were significantly more likely to reject foster infants than control mothers were. When adoption was successful, all of the abusive mothers maltreated their foster infants whereas none of the control mothers exhibited infant abuse. These findings suggest that infant characteristics do not play an important causal role in the occurrence of infant abuse and that abusive mothers may differ from nonabusive ones in maternal motivation or reactivity to stressful procedures.

Early experience affects the intergenerational transmission of infant abuse in rhesus monkeys

“…For example, the rate of infant abuse in this study was not significantly different in cross-fostered and non-cross-fostered infants. Moreover, abusive mothers abused their adopted infants with rates similar to those exhibited with their own biological offspring in previous years (21).…”

“…21 for details of the cross-fostering procedure). Seven female infants born to multiparous mothers with a history of abusive parenting were adopted and reared by unrelated control mothers (abuse͞control group), whereas nine female infants born to control mothers were adopted and reared by abusive mothers (control͞abuse group).…”

Neurobiological characteristics of rhesus macaque abusive mothers and their relation to social and maternal behavior

“…Furthermore, these individuals also abuse adopted infants with rates similar to those exhibited with their biological offspring, suggesting that infant characteristics play a minor role in the occurrence of abuse [24]. Instead, abusive behavior appears to be a stable maternal characteristic.…”

Is There Mother–Infant Bonding in Primates?

“…To investigate whether these claims are supported by empirical evidence, I analyzed a large set of infant cross-fostering data obtained from the following studies: Smith (1986), Holman and Goy (1988), Owren and Dieter (1989), and Maestripieri et al (2000). Data provided by these studies could be reanalyzed because these studies shared the following features: (1) mothers and infants lived in social groups rather than in individual cages; (2) mothers were born either in the wild or in captivity but had been raised by their own biological mothers rather than by humans; (3) the cross-fostering procedure consisted of temporarily removing two mother-infant pairs from their groups, placing mothers in standard squeeze cages, and switching infants between them; (4) the adoption attempt lasted a few minutes or hours and was immediately terminated if the infant was violently rejected (e.g., slapped or bitten) by the foster mother; no forced cohabitation lasting several days was imposed on mothers and rejected infants.…”

“…In both primates and humans, there exists considerable interindividual variability in maternal motivation during the postpartum period, and this variability also includes pathological expressions (e.g. Kumar, 1997;Maestripieri et al, 2000). The determinants of these individual differences in motivation and their consequences for later parenting and child development are still poorly understood.…”