Q. I read about an infamous and quickly-abandoned study decades ago in which babies in an orphanage were divided into two groups. The babies in one group had their physical needs met but were otherwise left alone; babies in the other group were also held and nurtured, in a word, loved. The unloved babies literally shriveled and died, while the loved babies thrived. I've also heard a little bit about studies of infant animals and maternal deprivation.

Does medical science have any actual physiological understanding as to why unloved babies can die? Would this suggest that further research and recognition of the importance of love, in its various forms, would be valuable to the understanding of health and healing in general and to the field of psychiatry in particular?

A. You are raising questions that were literally the life work of the great researcher, Harry Harlow (1906-81). His work with young monkeys provided with wire or cloth surrogate mothers established the principle that maternal nurturance is essential to the infant's physical and emotional well-being.

Harlow demonstrated that the need for affection creates a stronger bond between mother and infant than do physical needs, such as food. Some have certainly understood this research as proving an innate need for love, at least in young primates.

I'm not sure this can really be demonstrated scientifically--how, after all, do we measure "love"?--but we do have good data supporting Harlow's basic research, nevertheless. Regarding your question, though, we are just starting to understand the physiology of nurturance, maternal deprivation, maternal separation, and related issues. Most of the current biological research has been in animals, with very little in human infants, for obvious reasons.

Much of the research has focused on the effects of separation or deprivation on a hormone called cortisol, which is produced by the adrenal gland. This hormone normally equips us to handle both physical and emotional trauma and stress. However, if cortisol remains elevated for too long--or if the initial cortisol response to stress is inadequate--this may permanently affect the brain structure and function of the animal or human subject.

For example, one recent study found that early trauma--separation of the infant rat from the mother--predisposes the rats to intestinal problems, as adults (Solderholm et al, Am J Physiol Gastrointest Liver Physiol 2002 Dec;283(6):G1257-60). It was found that pretreatment of the separated rats with a chemical that stimulates cortisol production could actually prevent the stress-induced damage to the intestine.

There is growing evidence that early maternal separation or handling of neonatal rats can program widespread and lifelong changes in various brain chemicals that regulate cortisol production (Champagne & Meaney, Prog Brain Res 2001;133:287-302).

Whether similar factors are at work in abandoned or deprived human infants is not yet known, but we do know that individuals with post-traumatic stress disorders often show abnormalities of their cortisol system. Whether or not this argues for more research on love, I'm not sure--but I like the idea!

August 2003

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