By A.M., IANtB Science Editor
Jamie’s blog inspires some of the most colorful commenters. Recently, in response to an article that featured a breastfeeding five year-old, one very articulate individual commented, “This is how serial killers are made.” Well, this happens to be an area that has lately been of great interest among child psychologists, sociologists, and pediatric anthropologists. But let me start with extended breastfeeding itself, then I’ll talk about how serial killers are made. (When a mommy serial killer loves a daddy serial killer very, very much…)
What is the scientific consensus?
There is little data available on children who breastfeed past age twoish, because it is so infrequently done in the West and is therefore difficult to assemble a sample size that would yield valid results. However, given the data that we do have, and also given what we know about child development in general, the general consensus is that such concerns are unfounded. That is to say that every study that has examined this issue has found either no significant psychological effects, or has actually found positive outcomes associated with it. One very interesting study, for example, specifically found fewer mental health problems in adults who had breastfed longer than a year. And generally speaking, there is nothing about extended breastfeeding in and of itself that scientists view as cause for concern in terms of emotional, social, or cognitive development. In fact, quite the opposite is the case, as I will discuss in a moment.
It is well-known in the United States that the American Academy of Pediatrics recommends breastfeeding until at least age one, “and continuation of breastfeeding for as long as mutually desired by mother and baby.” I don’t feel like I should have to state this, because it is quite obvious, but they would not have included the “continuation for as long as mutually desired” part if they thought it was harmful in any way. (Remember, this is the same organization that does not trust parents to follow the simple rules of safe cosleeping, and therefore instructs them to simply not do it at all.) Notice that they didn’t write “and continuation of breastfeeding until they start to talk” or “until age four.” It just says “for as long as mutually desired.” They left it open. This is precisely how confident scientists and clinicians (who don’t always agree, lol) are that culturally-constructed concerns about weaning age are unfounded.
What is lesser-known in the U.S. is that the World Health Organization recommends breastfeeding for a whole year longer, until age two. And this is not a special recommendation for poor or at-risk mothers in developing countries. This is a recommendation based on what is biologically appropriate for our species. In 2008, the American Academy of Family Physicians released a position statement that included commentary that supported the WHO recommendations (emphasis mine):
As recommended by the WHO, breastfeeding should ideally continue beyond infancy, but this is not the cultural norm in the United States and requires ongoing support and encouragement. It has been estimated that a natural weaning age for humans is between two and seven years. Family physicians should be knowledgeable regarding the ongoing benefits to the child of extended breastfeeding, including continued immune protection, better social adjustment, and having a sustainable food source in times of emergency. The longer women breastfeed, the greater the decrease in their risk of breast cancer. Mothers who have immigrated from cultures in which breastfeeding beyond infancy is routine should be encouraged to continue this tradition. There is no evidence that extended breastfeeding is harmful to mother or child. Breastfeeding during a subsequent pregnancy is not unusual. If the pregnancy is normal and the mother is healthy, breastfeeding during pregnancy is the woman’s personal decision. If the child is younger than two years, the child is at increased risk of illness if weaned. Breastfeeding the nursing child after delivery of the next child (tandem nursing) may help provide a smooth transition psychologically for the older child.
Given that the average birth interval in the United States is about 2.7 years, that latter statement is an outright endorsement of breastfeeding a three year-old.
The AAFP’s statement acknowledges that many non-western cultures have much more relaxed social norms about weaning. Many of these cultures are in regions that are too poor for it to be a choice. I want to note that scientists or clinicians have made no observations, in any of these cultures, that indicate any differences in the psychological well-being of children who breastfeed beyond infancy when compared to the rest of the population. And given that we are all the same species, we are talking about more or less the same brains, here, and the same basic measures of psychological health.
I would also like to point out that I know of no reason to assume that any of the benefits (physiological or psychological) associated with breastfeeding have any sort of “expiration” date. The demonstrated benefits of breastfeeding at all ages is so compelling that I personally know scientists who breastfed/still breastfeed well into preschool years. We do know that the complex sucking instinct seems to disappear in humans around age 6 or 7. That is to say that, at some point, children seem to “forget” how to suck. So there are no breastfeeding college kids. Every kid weans. Every single one. Older kids refusing to wean is rare and simply isn’t enough of a problem for us to even bother researching it.
Breastfeeding for emotional health
So there you have it. Breastfeed until the cows come home (lol I’m so punny), because there are no known negative psychological effects. And as I hinted at earlier, there are potential benefits. So what are they? And what’s this got to do with serial killers?
Now, this is an area that gets a bit more into somewhat speculative territory. Here is where we infer some things based on what we know about child development, maternal-child attachment, and the complex set of behaviors associated with breastfeeding.
Laying the foundation
…Which brings me to my first point that is foundational to a complete understanding of breastfeeding. This is going to sound like it has more to do with the case for breastfeeding in general than for extended breastfeeding specifically, but frankly there is no reason to think that there is some kind of expiration date or definitive end to any of the developmental processes I’m about to describe.
You see, in addition to being nutritive, breastfeeding is also behavioral. In fact, some of the breastfeeding benefits you hear about, such as improved IQ and school performance, may be as much attributed to the behaviors associated with it as it could be to the nutrients in the milk. (Some may say even more so, depending on what kind of researcher you are talking to!) This is by virtue of the fact that breastfeeding requires a level of physical closeness to baby and active participation for the mother that aids the baby in its neurological and social development. First, a call-and-response feedback loop is set up wherein a baby learns that crying=warmth, food, and mommy awesomeness. Then, the eye contact, touching, talking, etc that occurs during the act of breastfeeding—and the responsiveness that these behaviors (and the associated hormones) elicit in the mother—conspire to create a reciprocal relationship between the mother and child that is reinforced by a hormonal reward system. (A similar process does occur in fathers, if you’re wondering.)
Through this relationship, the infant is developing an internal working model of how the world works. Is it safe or is it secure? Do I have agency or not? Can I rely on people or not? This reciprocity that I described—which many mothers describe as a “dance” or being “in sync”—is the foundation for the development of empathy—and empathy is what stops you from hurting other people.
…Sure, a lot of this can be, more or less, reproduced without the breast–if you work very, very hard at it and know what you’re striving for. But breastfeeding provides a biologically-based structure within which the mother-infant bond is reinforced, and both individuals are trained to communicate more effectively. Via instinctual behavior and hormones, breastfeeding makes everything run a whole lot smoother and with less effort on everybody’s part. So deeply ingrained is this system in our biology, so long evolved, and so finely calibrated by natural selection, that I am compelled to wonder, sometimes, if breastfeeding could—dare I say it!—save the world.
Anyway, this is a pretty hot area of research right now, especially in light of concerns over violence in schools, teen suicide, etc.
Building on the foundation: the Evil Baby Orphanage
“So breastfeed your kid for the recommended year, then stop,” you might say. But like I said before, we have no indication of any sort of expiration date on any of this. And also here’s a thing: Social development doesn’t stop at a year. Theory of mind, one of the major milestones in the development of empathy, doesn’t appear until around age 5. The vast majority of brain growth occurs during the first 6 years of life.
And as for creating serial killers…Unfortuntately, we can’t all become time-nannies and travel back in time so we can put Baby Hitler in an Evil Baby Orphanage run by monks in Tibet who would teach them anger-management skills and love them unconditionally. …But we can raise well-adjusted kids who don’t want to murder people. And yes, that responsibility lies most squarely on the shoulders of parents. It’s hard to fathom, but there’s always that potential that it could be your kid…Okay, maybe we don’t want to be that extreme. Say we’re just talking about any kind of antisocial personality or behaviors, such as manipulating or hurting others. These can all have a major genetic component, in addition to environmental variables. And in those people who have a genetic predisposition towards antisocial behavior, breastfeeding and other highly responsive parenting practices may have the potential to have a moderating effect on the bad deck of genetic cards that kid got. And this is important to note because you don’t always know, while the kid is still in preschool, that he or she will have antisocial tendencies as an adult.
It sounds a little extreme, but whenever I talk about this, I am reminded of the psychopath researcher James Fallon, who found out that he himself has brain structures that resembled the individuals in his study. He believes that he never fulfilled the predictions of his genetics because he was born after several miscarriages, and therefore was deeply cherished by his parents and given a very happy childhood. “I was loved, and that protected me,” he told Smithsonian Magazine last year.
Whatever antisocial behavior, in your mind, is scary and you want to protect your child from—whatever that is for you, I’m not saying you can prevent it with extended breastfeeding. I’m saying it can have a moderating effect. I’m saying it can help, if you want to let it. Help you, and help them.
Breastfeeding: the meltdown killer
And never is there a time when parents feel like they could use all the help they can get than during the “terrible twos.” In general, breastfeeding during the toddler years can be an absolute godsend because, when it is done on demand (within reason, of course — they are able to start learning to accept reasonable limits at this age) it allows the child to regulate his or her own blood sugar, thereby helping to prevent meltdowns or even stopping one in it’s tracks. Even if you are offended by the sight of a toddler breastfeeding in a restaurant, wouldn’t you rather simply look away and enjoy your meal in peace than listen to a tantrum?
I know it seems backwards to view parent-assisted regulation of emotions as beneficial, especially since it sort of goes against idealized notions of “self-soothing” and independence that is characteristic of American values. But the field of developmental psychology has really showed this to be the case. The longitudinal studies that look at the varying characteristics of the parent-child relationship and compare them to the behaviors observed in the child as an adult seem to suggest that an intense parental investment early on seems to yield greater independence later on in life — even beginning in middle childhood. In the instance of breastfeeding in assisting the child in developing emotional regulation, what’s basically happening is not so much that the mom whips out her boob every time her kid makes a peep. It may be like that at first, when the kid is small, but later on the child learns to recognize when he/she needs comfort — this is the beginning of emotional self-awareness — and then initiating the feed on his/her own, either by latching on or asking to latch on.
Other concerns within the larger issue of extended breastfeeding and mental health
Maybe it’s the norm in other cultures, but not in ‘Murica!
One might be able to make the case that breastfeeding beyond the normal accepted age in a given culture is maladaptive within the context of that particular culture, and then you would definitely have an argument. However, no such evidence has been found to support this notion within our own culture. It is simply uncommon, and therefore is a bit of a pain for mothers to do by virtue of the fact that they cannot do it in public for fear of being shamed. And as the child becomes more aware of the social attitudes around her, her parents would do well to remember that the child will social reference them for how to react and model a sense of parental self efficacy, reassuring the child as necessary. However, that is really the only downside to it that I know—and again, even when this is considered, there are no lasting affects on emotional or social development.
The kid will get bullied
Along a similar vein are concerns that a school-aged child will get bullied if peers find out that a child is breastfeeding. Again, this is so rare, and often done in secret, so there are no studies that I know of to cite. However, it may just be that it is simply not enough of a problem to even make it worth a researcher’s time. Given how infrequently a school-aged child breastfeeds in a given day, it is not likely that his friends will ever see him do it or even ever know about it. At this age, breastfeeding sessions are so infrequent, and their duration so short, that I can think of many other possible parental choices that I could potentially be far more consequential in terms of the child’s development, such as their overall parenting style, their level of sensitivity to the child, school choice, nutrition choices, etc.
You’ll give him a boob fetish/make him gay/make her gay
This one is just stupid. It appears to be based on an understanding of psychology that results from not paying attention at all in Psych 101, where Freud is taught in a historical context and not as if he were right about everything. When it comes to raising children, people love to pull out the psychspeak, but it seems like everyone’s knowledge of psychological research ends with the behaviorists of the first half of the 20th century. “Don’t respond to whining! It’ll reinforce the behavior!” Spoiler alert: We’ve learned a lot since the 1950’s. Amazing, how science works.
A note about autism
Autism, another common concern among parents, is difficult to diagnose before age two, and often that is merely a preliminary diagnosis and requires several more doctors visits (with a specialist, that is) before the doctor can be sure of the diagnosis. Most kids are not diagnosed until well into kindergarten, and almost a third of children on the autistic spectrum are still not diagnosed by age 8. We know of at least one study that has associated early weaning with increased risk of autism, and one of the hypothesis regarding the etiology of autism suggests that one of the ingredients in breast milk, insulin-like growth factor (IGF), might have a moderating effect on the development of autism. My review of this literature revealed that this is an area that is indeed in dire need of further research. However, if I had autism in my family (which I do) and felt my child was at risk for developing the disorder, I’d consider the nutritional composition of breast milk, as well as what I know about breastfeeding behavior and social development, and the fact that this intimate social component of breastfeeding is so similar to the sort of “floor time” therapies that are recommended for children with autism, and conclude that I had enough reasons enough to continue breastfeeding at least until I could reasonably assume that we were “in the clear.”