Breastfeeding and "Instinct"

In his New York Times  op-ed piece of July 11, Nicholas Kristof described a situation in Mali where a 3-week-old-baby was not-very-slowly starving to death because his teenage mother did not really know how to nurse him. As Kristof commented, “Nursing a baby might seem instinctive, but plenty goes wrong”, and this is very true.

I want to comment on this by examining first the issue of “instinct” in breastfeeding, and then talking about how customs and past history can interfere with nursing a baby.

When people describe a human behavior as “instinctive”, they commonly mean that the behavior does not have to be learned or practiced, but simply emerges, fully organized and in the right sequence, when a certain stimulating situation is present. In this way of thinking, often, most people of the right age and sex are expected to display a particular “instinctive” behavior, but it’s also possible for someone to be lacking the entire behavior--  for example, to have “no maternal instinct”.  Some “instincts” are thought of primarily as motivations, so a woman who did not want to have children might be said to have no maternal instinct, but one who wanted children but was a poor caregiver might also be spoken of in that way.

People talk about human “instincts” as just described because they are working with the analogy of humans to animals, and they believe that animals of all species from worms through mammals are determined in complex, survival-related behavior by unlearned, innate factors. However, this is true only to a limited extent. Lower animals respond to specific stimuli by a series of reflexes, each of which is indeed unlearned, but all of which occur in an effective sequence only when a series of environmental events triggers them. Mammals do not show these complex behaviors like courtship or infant care unless they have had related learning opportunities. For example, it was shown many years ago that female rats that wore a “cone” protector ) like those used after dogs have surgery) during pregnancy, and who thus could not do their usual grooming sequence, which includes the genitals, did not after giving birth go through the normal steps like tearing open the amniotic sac, licking the pups to clean them, and eating the placenta. In similar work, male rats and virgin female rats who had never seen rat pups did not care for them by retrieving them when they wandered from the nest, but after they were able to see the pups for several days, they began to behave as if a “maternal instinct” were at work in them.

Analogies between human and animal behavior are not always productive, but they are certain to be problematic when they are based on a misunderstanding of “instincts” in animals. As it turns out, the more complex the organism, the more experience and the environment affect behavior, and the less behaviors like breastfeeding can be regarded as automatic and innate.

So, what are the factors that guide breastfeeding, and help decide whether human mothers will nurse thriving babies, or will find themselves in the situation that Nicholas Kristof describes? There are certainly some biological factors at work. Colostrum and, later, milk are secreted initially in response to hormonal stimulation. Lactation, or milk production, is followed by actual breastfeeding, the transfer of milk from the breast into the baby’s mouth. Breastfeeding involves two maternal reflexes--  yes, these are innate by definition--- the erection of the nipple so the baby can take it into the mouth, and the “let-down” or ejection reflex that squirts milk out of the breast (it doesn’t flow passively as if the baby were sucking from a straw).  These reflexes are triggered by the baby’s own reflex actions. When the baby’s cheek is touched (for instance, by being held against the mother’s chest), he or she reflexively “roots” with a pecking action that brings the mouth to the nipple. The touch of the nipple far back in the mouth triggers the baby’s sucking reflex; this is again not like sucking from a straw, but  more like “chomping” on the area just behind the nipple, and that pressure stimulates the mother’s ejection reflex, squirting milk into the baby’s mouth.

It all sounds wonderfully organized, and it is--  but when mothers are very inexperienced, when they have no or the wrong advice, or when the baby is weak or sick, there may well occur the vicious circle that Kristof’s column described. What are some of the problems? These are different from one cultural group to another, but some of them are as follows:

In some parts of the world, it is held that babies should not be put to the breast right after birth and should not be allowed to suck colostrum, the sticky fluid that is secreted before the true milk develops. Prohibiting colostrum starts a whole cascade of unfortunate events. Colostrum contains a large dose of antibodies that the baby cannot yet make for itself; colostrum is available at the time when the baby’s sucking reflex is strongest and mother and baby are most likely to get off to a good start. Early sucking stimulates the breast and gives a head-start on establishing the milk supply, which can easily diminish or dry up during the first two weeks after birth. (After the milk supply is established, it is maintained much more easily without so much sucking.)

It’s hard to overcome customs that can interfere with breastfeeding. Unfortunately, several decades ago, there were also some events that interfered even more with breastfeeding than customs did, especially in African nations. The repercussions of these events are still being felt.

In the 1960s and ‘70s, Western formula manufacturers started an advertising campaign in Africa that declared that formula feeding was the way to have healthy babies. This would not have been so harmful, except that formula feeding only works well when there is refrigeration, methods for sterilizing bottles, clean water to make up the formula with, and an understanding of infectious disease. Where these were absent, babies died in their thousands over a period of years. In addition, the mothers who should have learned breastfeeding methods from older women did not do so, and so could not later help new mothers as they began to breastfeed.   

Because this happened, the chain of intergenerational transmission of knowledge about breastfeeding was broken. Most young mothers can benefit from some advice about how to hold the baby and how to be sure that the nipple is taken far enough into the baby’s mouth, but without the traditional access to knowledgeable older women, only those who were fully literate had a good chance of finding solutions to common problems like apparent lack of milk or like painful nipples. As a result, we now see babies dying even though their mothers have abandoned the formula-feeding approach and very much want to breastfeed.

If people make the wrong assumptions about “instincts”, they won’t see that the solution to this problem lies in compensating with helpful support to young mothers for the intergenerational break that started a generation ago.