Re: Becoming altricial/bi

J. Moore (
Thu, 5 Oct 95 15:24:00 -0500

Tk> >Pa> My case is that the development of *bipedalism* necessarily
Tk> >Pa> involved an altricial period. The physical development
Tk> >Pa> would be that you see in your own children. They have to
Tk> >Pa> learn to walk. But the real thrust of

Tk> Yes.. they have to learn to walk. And it is interesting to note that
Tk> much of what Hardy developed his originial AAT theory about was the fact
Tk> that infants can actually swim BEFORE they can walk. I hope I don't have
Tk> to defend this post. I have posted references to this post before. But

Yes, you have, and I have posted the actual full information from
the "Baby Swimming Ref", including the parts that AATers
(suspiciously enough) never seem to manage to mention.
I repeat it below.

Tk> normal healthy human infants are capable of breath control, and swiming
Tk> actions which propel them in a specific direction up to the age of about
Tk> 3 or 4 months, at which point they misterously loose this ability. My
Tk> guess is that they become too heavy to be completely supported by their
Tk> fat deposits.

>From my post of 9-12-95:

JM>> You mention the "enigma" of "swimming human infants". This is a
JM>> hoary chestnut indeed which has been used for quite some time by
JM>> many AATers. The reference they give is "M. McGraw, Journal of
JM>> Pediatrics, 1939:485-490.", and they do give the reference, so one
JM>> can assume they've read it and know what it says. They always
JM>> seem to mention the human infants and how their movements are
JM>> usually "rhythmical and organized" and are "ordinarily sufficiently
JM>> forceful to propel the baby a short distance through the water".
JM>> They don't seem to ever mention the fact that the same study
JM>> looked at other mammalian infants (opposum, rat, kitten, rabbit,
JM>> guinea pig, and rhesus monkey) and found that they behaved the
JM>> same way: "these rhythmical movements of the human infant are
JM>> quite similar to those of other young quadrupeds in water".
JM>> (Note that an older chimpanzee was also tested and, just like
JM>> older human infants, was inactive when placed in the water. Note
JM>> too that this study found that "at no time did any baby show
JM>> himself capable of raising his head above the water level for the
JM>> purpose of breathing". So what we really find here is not so much
JM>> "swimming" as infant mammals slowly drowning without a struggle.)

Tk> Does say a lot though, swimming before walking?
Tk> Troy

Says a lot that you and other AATers never mention that this
"swimming response" (holding breath and rhythymical movements)
has been shown to be a general mammalian infant response, and that
this information that showed this is contained in the same article
(on the same page!) as the info on human babies. Funny that you
managed to miss it then. Funny, or suspiciously "convenient".

Jim Moore (

* Q-Blue 2.0 *