Compared to the animal literature, the human literature on genetic, hormonal and neural mechanisms underlying the initiation, establishment and maintenance of maternal behaviour is small. While there are obvious parallels in the behaviour itself between human mothers and other mammals, there is little evidence for the primacy of biological mechanisms as opposed to cultural and experiential factors. In particular the concept of a human sensitive period after birth when ‘bonding’ must occur, analogous to the sensitive period in mammals, has lost importance. However there are important similarities between the effects of poor maternal care in other mammals and in human children, specifically inappropriate overactivation of the hypothalamo-pituitary-adrenal axis (HPA) and a subsequent cascade of diverse and adverse consequences. It is likely that such enhanced stress responsiveness and its results does impact on future maternal care, creating the possibility of transgenerational cycles of inadequate maternal behaviour. The implications for antenatal, postnatal and child protection interventions are briefly discussed.