Monkey and human mother-child relations are strikingly similar
Monkey and human mother-child relations are strikingly similar

Language means that we have self-consciousness, which makes us a unique species able to control ourselves and our environments in ways that other animals cannot. However, a visit to the Monkey Sanctuary, near Looe in Cornwall, provided striking evidence to me of connections between monkey mother-child relations and that in humans.

The monkeys there have usually been badly deprived of love or maltreated by humans. The scientists use their understanding and painstaking care to nurture the monkeys back to a more stable emotional state. As a review paper shows, there are important parallels between the impact of early maltreatment in other mammals and humans, and key implications for prevention of human emotional problems.

The kind of early care a monkey receives precisely predicts its brain chemistry and the kind of adult it will become. Rhesus monkeys separated from their mothers at birth and reared without an alternative parent, only with their peers until the age of six months, are more easily scared of strangers and unfamiliar experiences than mother-reared ones. They slide to the bottom of monkey status hierarchies, whereas the more secure, socially assured, mother-reared monkeys are at the top.

When threatened by social separation or isolation in later life, those monkeys separated from their mothers at birth have different brain and body chemistry. When they become mothers themselves, they are significantly more neglectful or abusive of their offspring than those who were mother-reared, repeating the cycle of deprivation.

Less extreme variations in early care also emerge as having powerful and enduring effects on monkeys. If a group of infants are only briefly and occasionally separated from their mothers during the first 14 weeks of life, they are fully as insecure as young monkeys reared solely away from their mothers; tested at four years old they still have depleted brain chemicals.

Patterns of mothering are passed down from mother to daughter through the specific amount of care given and received. Amount of contact with mother precisely predicts the amount that she bestows on her own daughter.

The similarity in mothering across generations could be simply a genetic inheritance, but this has been disproved. The amount of contact with the particular daughter has been compared with the mother's average for all of her daughters. A daughter's subsequent mothering reflects her particular experience rather than the average for all of her sisters. The unique care received determines subsequent pattern of mothering, rather than a genetic tendency inherited from the mother.

Another theory is that a genetically difficult baby could make the mother uncaring. This was contradicted by a study of what are called highly reactive infant monkeys – ones that are very difficult to care for because they overreact to the slightest sound or movement.

They were fostered out to either average mothers or exceptionally nurturing ones. The exceptionally nurtured young monkeys grew up even more socially well-adjusted than normal infants fostered by average mothers. Nurture was so influential, in other words, that it could turn a difficult infant into a superior adult. Furthermore, when the generation of offspring in the study grew up and themselves had infants, their parenting style, whether exceptionally nurturing or average, exactly mirrored the kind of care they had received as infants. This was regardless of whether their original infant personality had been highly reactive or not.

Much of what goes for monkeys seems to go for humans too. It's a simple but important point: babies and toddlers need consistent loving care if they are to grow up secure and mentally healthy. Well-conceived and executed interventions that improve mother-infant relationships can make all the difference.

Review: O'Connor TG et al, 2006, American Journal of Preventive Medicine, 31, 175-81. More Oliver James at