Where Shall I Put the Baby?

The women’s  movement has made serious contributions to the study of human evolution by considering issues that male scholars ignored. Anthropologist Dean Falk has explored mother and infant relations among primates and produced a book, Finding Our Tongues: Mothers, Infants, and the Origins of Language, that explores new ground. Theoretically, anybody could have studied its issues, but men don’t seem to have gotten around to it. Take lullabies, for example. We all know something of them, but women appear to have wondered about them. The footnotes on the topic all refer to women (Sandra Trehub, Anna Unyk, and Laurel Trainor).

Lullabies are used throughout the world to soothe infants and lull them to sleep. They are distinctive from other songs—so much so, in fact, that adults listening to songs in unfamiliar languages can distinguish the lullabies from the equally slow nonlullabies. [p. 36]

 So there we have another item to the very short list of things that are unique and universal to the human group. Why wasn’t that one pointed out by somebody 50 years ago? Why didn’t I wonder about it 40 years ago?

So without question this book has a lot to add to the stew of inquiry into speech origins. But it  goes too far in setting down an actual would-be explanation for the cause of it all. The book’s critical passage comes in the 4^th chapter.

Long before baby slings were invented, mothers put their helpless babies down nearby as they went about their daily tasks. … I believe that at this point in evolution, mothers started maintaining vocal contact with their infants. Soothing voices would have periodically substituted for cradling arms as busy mothers lulled their babies to sleep or reassured them that they were near. I have dubbed this the “putting the baby down” (PTBD) hypothesis. [57-58]

This hypothesis rests on a couple of points. The main one is that as the human lineage became increasingly erectit became difficult for the females to deliver babies easy. The evolutionary solution was to give birth to immature babies small enough to squeeze through the birth canal. This solution had its own difficulty, the immature babies were not yet strong enough to hold on to the mother’s hair and required constant support. The mothers had to hold them up, not for just a few days as chimpanzee mothers do, but for weeks, even months. Holding newborn chimps slows the mothers down for only a few days, but mothers who cannot feed themselves easily are themselves at risk. Individuals cannot lag behind for months and expect to survive, especially when they need to eat enough both to keep themselves fit and to nurse a healthy newborn.

It is an important point: infants in the human lineage have been unusually dependent on others for a very long time and this dependence rests on special evolutionary adaptations.

There is, of course, the question of which came first, the dependence or the adaptation. Falk assumes the dependence led to the adaptation, but offers no evidence for it. Things might have changed socially so that the dependence became possible. Or, this being biology, the two might have co-evolved.

Another issue is something slipped into the argument. It is notable that putting the baby on the ground is very rare now. I have seen many village women working hard in the fields with their babies on their backs. The babies were not hanging on like monkeys, but were supported by cloth. Falk calls these supports “baby slings” and says they are almost universal:

Everywhere in the world nonindustrialized world, babies are carried on their mothers’s or babysitters’ backs, hips, or bellies in baby slings. [34]

The reference to “babysitters” is important, because babies are raised socially throughout the world: by grandmothers, aunts, neighbors, and older siblings. Even fathers join in the effort. Any one of these people are liable to carry an infant. I have seen little girls carrying toddler-sized brothers or sisters on their back. Falk’s book includes a fine pair of photos [p. 33] showing an Ethiopian girl with a sibling in a baby sling, and next to her is Falk’s  granddaughter holding a doll. The human maternal  instinct is not limited to human mothers. Human society is quite remarkable for its distribution of responsibility for the young. As Falk points out, this sharing of the responsibility by the group and trusting of the others by the mother is unknown among other primates. So that’s a second adaptation that supports the survival of dependent infants.

We have two unknowns in this story:

1. when were baby slings invented; and,
2. when did human mothers become so social they trusted others to hold their babies?
   

So when Falk writes, “Long before baby slings were invented…,” she doesn’t know when that was. Homo habilis was using stone tools about two and a half million years ago. If they were smart enough to create slicing blades, weren’t they smart enough to create baby slings? I don’t  know, but I cannot just rule it out a priori. They might have been made from vines tied together (I have seen villagers create rope that way), or they might have made them from skins. With blades, they could have cut tough vines or prepared hides. So, while we certainly do not know, we cannot assume baby slings were impossible that long ago.

Another thing about slings, the fact that they have become universal, suggests that whatever intermediary solution was found between their need and their invention was an inadequate substitute. If vocalizations were the substitute, they did not satisfy.

If two million-year-old baby slings seems too much of a stretch, we still have the business of baby sitters. When did they become  common? Instead of putting the baby down and maintaining contact through vocalization, they might have created a mutually dependent community. Some tended to the children while others foraged for food, and then everybody came together for a shared meal. Indeed, that system did appear at some point. Why not 3 million years ago?

By the way, there is a clear evolutionary alternative to the vocalization solution: silent immobility. A savanna species whose mothers are unable to transport their young and also lacking the social support that humans enjoy is the Thompson’s gazelle. Their young survive by not moving. They wait patiently, without moving until their mother’s return to nurse them. If the mother never reappears, they stay still until they die. The human lineage could have gone that way if they lacked both baby slings and social support.

Ultimately, my doubt rests on something more fundamental. Speech’s unprecedented quality comes from its triangular nature: speaker and listener pay joint attention to a third thing, a topic. The mother-baby vocalization is interesting, but pairs like that are nothing new in nature. I would be more open to the suggestion that babies were the original new topic. –“Can I hold the baby?” –“Of course.” –“Wow, look at this smile. Isn’t she beautiful.”  Now that’s the speech triangle.

Falk’s book is well worth reading, despite the grave questions about its primary thesis, and next week I’ll discuss some of the many intriguing thoughts it provokes. I cannot imagine anyone who is interested in this blog who would not be interested in what the book has to say.

Comments

[JoseAngel]

A very suggestive entry, and book I should say. It suggests, too, that the link between bipedality, difficult births, neotenical (and helpless) infants, and community bonding needs further reflection and research. And the issue of speech comes right in the middle of that, of course.

[Mariana]

Very interesting, I learned a lot about the basics of human beings. Txs.
I am happy cause my blog is called singyourownlullaby, and now I know information about lullabies I did not know before. Txs again

[Ergo Baby Carrier]

As Falk points out, this sharing of the responsibility by the group and trusting of the others by the mother is unknown among other primates.
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BLOGGER: I'm letting this comment stand even though I suspect it is an ad. Doubt goes to the runner.

[Moby Wrap]

A savanna species whose mothers are unable to transport their young and also lacking the social support that humans enjoy is the Thompson’s gazelle. Their young survive by not moving. They wait patiently, without moving until their mother’s return to nurse them.
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BLOGGER: Yes, and I once saw a jackal kill a young gazelle who made the mistake of moving when a hawk swooped at it. However, Tommy gazelles have a fixed territory, so the mothers don't go too far.

[Katherine]

You might be interested in the article by Archaeologist and anthropologist Timothy Taylor who hypothesises that tools use came before Homo species, that Australopithecines were responsible for the stone tools and used these to create baby slings to carry their young. Enabling the development of bipedalism and big brains. http://gizmodo.com/5619821/artificial-ape-man-how-technology-created-humans.

Here http://www.duncancaldwell.com/Site/Baby_Sling_Adaptations.html Duncan Caldwell hypothesises slings allowed for premature birth and brain development post natally and that hair loss resulted to combat parasites in hide slings.