Babies must crawl before they walk, parents and pediatricians agree. Crawling has also been held up as a prerequisite to the normal progression of other aspects of neuromuscular and neurological development, such as hand-eye coordination and social maturation. But new research may knock the legs out from under this conventional wisdom.
According to anthropologist David Tracer of the University of Colorado at Boulder, babies of the Au hunter-gatherers of Papua New Guinea do not go through a crawling stage. Instead their parents and other caregivers carry them until they can walk. Yet Au children do not appear to suffer any ill effects from skipping this phase. In a presentation given to the American Association of Physical Anthropologists in Chicago this past April, Tracer argued that, in fact, not crawling may be entirely normal and possibly even adaptive.
In his observations of 113 Au mother-child pairs, Tracer found that babies up to 12 months old were carried upright in a sling 86 percent of the time. On the rare occasions when the mothers put their infants on the ground, they propped them up in a sitting position, rather than placing them down on their stomachs. As a result of spending all of that time upright, Au kids never learn to crawl. (They do, however, go through a scoot phase in which they sit upright and propel themselves along on their bottoms. Tracer says the Au believe that this scooting, rather than crawling, is the universal human prewalking phase.)
The Au are not alone in discouraging their children from crawling. Tracer notes that babies in a number of other traditional societies—including ones in Paraguay, Mali and Indonesia—are raised this way. Furthermore, he observes, neither do our closest living relatives, chimpanzees and gorillas, put their youngsters on the ground very often. Thus, it may well be that our early hominid ancestors toted their babies around, too, rather than letting them crawl.
Citing a study of Bangladeshi children showing that crawling significantly increases the risk of contracting diarrhea, Tracer proposes that carrying infants limits their exposure to ground pathogens. It also protects them from predators. He therefore contends that the crawling stage is a recent invention—one that emerged only within the past century or two, after humans began living in elevated houses with flooring, which would have been much more hygienic than dirt.
Wenda Trevathan, an anthropologist at New Mexico State University, agrees that babies were probably rarely placed on the ground in the past, adding glowing embers as another potential hazard. Tracer’s work “highlights how narrowly we view normal infant development,” she remarks, “and calls into question the tendency to judge all human infants on the basis of Western infants.”
Note: This article was originally printed with the title, "Hitching a Ride."
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13 Comments
Add CommentThis is another fascinating insight into not only the varieties of supposedly "normal" human development but also into the biases scientists wear when we study phenomena. As a physical therapist I was taught that all infants progress through the crawling stage, as a means of developing reciprocal movement necessary for walking, as well as postural reflexes and strength. Pediatric therapy to this day often includes attempts to facilitate crawling in developmentally delayed children. Anectdotal reports of children who never babbled or spoke at all until a delayed date, when they spoke in full sentences, also suggests that theories purporting the "function" of babble in normal speech development may be questionable. I'm sure there are other examples. It truly is amazing how much is hardwired into infant development, from a neuromotor standpoint.
Reply | Report Abuse | Link to thisAt ten months, our tiny daughter stood up and started walking. Old wives tongues clucked, warning that having skipped the critical crawling stage, she would surely have trouble later with reading and fine motor skills. My mother countered that doing the same thing hadnt prevented me from learning to read at four. Later, as the tiniest and youngest in her class, she inspired a series of grade school teachers to warn that she was an over achiever who would eventually and surely run out of steam and fall behind her peers. Thirty years, a PhD at Yale and a full professorship at Harvard later, we are still ready to console her when that happens.
Reply | Report Abuse | Link to thisWhile it appears that the crawling stage is not required for normal development, as the article and sellenwright assert, I think the article's author might have been too quick to suggest that the ideal of a "crawling stage" is an artifact of the last century or so of Western culture. The Riddle of the Sphinx (at least seventh or eighth century BC) suggests that the crawling stage was a common human experience in Greece.
Reply | Report Abuse | Link to thisThere is some reason to suspect that a major factor in sudden infant death is placing the infant in a horizontal position, whether face up, face down or sideways. If so then prevention of SIDS could be achieved as described in this article. Are there any data on SIDS among the Au of New Guinea or other remote populations where use of the upright posture is exclusive at all times?
Reply | Report Abuse | Link to thisRE Tracy RTRACY@LSUHSC.EDU
My daughter never crawled. She learned early to 'scoot' around on her buttox and went directly to walking.
Reply | Report Abuse | Link to thisI certainly see the benefits under the circumstances described of "avoiding" the crawling stage (disease, etc.). But the article fails to mention the average age at which those who don't crawl first start walking vs. those that do. My child for example started her "scoot to crawl" phase very early and I can't help but believe her coordination and core muscle development is better because of it. She will be walking very soon at almost 9 mos. The exploration and visual stimuli that a baby experiences while crawling is also another benefit in development that phase provides. I think that it would probaby impact the development of their independence as well. In this society your independence is definitely a survival tool. The "fact" that crawling may not be necessary doesn't mean that the crawling phase is not beneficial or even a stage that was a next step in our evolutionary process.
Reply | Report Abuse | Link to thisI certainly see the benefits under the circumstances described of "avoiding" the crawling stage (disease, etc.). But the article fails to mention the average age at which those who don't crawl first start walking vs. those that do. My child for example started her "scoot to crawl" phase very early and I can't help but believe her coordination and core muscle development is better because of it. She will be walking very soon at almost 9 mos. The exploration and visual stimuli that a baby experiences while crawling is also another benefit in development that phase provides. I think that it would probaby impact the development of their independence as well. In this society your independence is definitely a survival tool. The "fact" that crawling may not be necessary doesn't mean that the crawling phase is not beneficial or even a stage that was a next step in our evolutionary process.
Reply | Report Abuse | Link to thisPerhaps being carried for such a long time makes the child feel more secure as well as experience the adult world it will mature into. The constant movement of the Mother may also help in developing balance , since that head with it's inner ear balance mechanism, is always in motion and may be a better "prerequisite to the normal progression . . . of neuromuscular and neurological development, such as hand-eye coordination and social maturation." than crawling! My oldest son never crawled. I carried him on a sling and was teased for it and warned I would make him into a spoiled weakling - well, he has always been at the top of his class, attended college on full scholarship and is know for his incredible sense of balance. He is a powerful and graceful Modern Dance dancer with Pilobolus Dance Company. He has done quite well for himself and is no mama's boy.
Reply | Report Abuse | Link to thisJamesDavis- you say to let the child decide which is better for them, but then in that same comment you state that, if they happen to choose scooting, you will judge them as "a little retarded and post-ape"? Holy Cow!
Reply | Report Abuse | Link to thisbierluvre, other people find that their crawling babies walk LATER than their non-crawling babies and chalk it up to the fact that the ones who crawl already have a way to get around, while the ones who start walking from the get-go use that as their only form of locomotion.
Reply | Report Abuse | Link to thisIronically, this anecdote demonstrates the perils of anecdata quite nicely, I should think.
Good point. I thought I might have been the only one who noticed that. Moreover, I may be no expert on ape behavior, but I wasn't aware that infant apes "scooted". The article seems to imply that they are simply carried until they can move around on their own. As such, I wouldn't think that "scooting" would be best described as "post-ape".
Reply | Report Abuse | Link to thisI isn't surprising that non-traditional theories would be challenged. The author of this article makes a good point when he reminds us how narrow our views are. We tend to view history and judge the world based on modern western standards as though our imaginations and perspective were limited to our small experience of life.
Really? This is a theory? Why mention the few cultures where babies don't crawl and not all the ones where they do?
Reply | Report Abuse | Link to thisI agree with PT's comment: "This is another fascinating insight into not only the varieties of supposedly "normal" human development but also into the biases scientists wear when we study phenomena."
Reply | Report Abuse | Link to thisWe are ready to throw out all of evolution because in one tribe crawling is not practical--there are dangers in the jungle, including snakes,etc. although in THE CONTINUUM CONCEPT, author Leidloff describes native babies crawling up to the edge of tiger pits, but never falling in.
This author misses that the core genius of our species is amazing adaptability: Native Americans who use cradle boards (although they still encourage crawling) walk differently as a result--but they survived in a mobile, horse adapted lifestyle, where creadle boards were needed.
What did NOT work were pediatricians proclaiming that SIDS could only be avoided by preventing infants from lying on their bellies, despite millenia of babies doing just that. After PTs saw that such "back lying" resulted in delayed development, lack of cervical curves, and the inability to access the Righting Reflex or the ability to roll over (Nature's ways of avoiding SIDS), the pediatricians allowed "tummy time," but with great cautioning of worried parents.
Actually, data show that SIDS is less frequent in societies where infants sleep with the mother, whose breathing stimulates the newborn's breathing patterns. Having babies "sleep in their own rooms" was a notion created by turn of the last century architects who had built flats in London with an "extra" room they marketed as "the nursery." From that marketing has sprung two centuries of leaving babies to cry all night for their parents, and parents hiding in their bedroom, both parties suffering so the babies "can develop independence." Sure.
I have also worked with many patients who missed crawling or another normal phase--or were severely injured and in order to reclaim mobility found those phases "filled in the blanks" very quickly.