The study of mother-infant bonding was stimulated by concepts and data impo
rted from animal research. However, the occurrence of mother-infant bonding
in nonhuman primates has not been systematically investigated. Information
obtained from naturalistic observations of infant adoption, experimental s
tudies of infant cross-fostering, and studies of mother-infant recognition
in primates suggest that the first few days of the postpartum period are a
sensitive period for maternal motivation. During this period, primate mothe
rs are highly attracted to infants and motivated to take care of them, and
therefore in optimal conditions to bond with their offspring. This does not
necessarily imply, however, that bonding cannot occur during subsequent po
stnatal periods or that small differences in time spent in contact by mothe
r and infant during the early postpartum days have long-lasting consequence
s for development or parenting. The determinants of temporal changes in mat
ernal motivation during the postpartum period or of individual differences
in maternal motivation have been poorly investigated in humans. The primate
evidence can stimulate human research in this area and enhance our underst
anding of some adaptive and maladaptive processes underlying parenting beha
vior and child development. (C) 2001 Academic Press.