The "Swimming Babies" reference
You might wonder, as one thoughtful
participant in the online AAT/H debates did, why do so many babies drown
in bathtubs and swimming pools each year?
For AAT/H proponents tell us, as evidence
for their theory, that human babies naturally hold their breath and swim.
This is a hoary chestnut indeed
which has been used for quite some time by many AAT/H proponents (including Hardy, Morgan, and Verhaegen).
This time they usually actually give the reference: "M. McGraw, Journal of Pediatrics,
1939:485-490.", so one might assume they've read this research paper and
know what it says.
They always seem to mention the human infants and how
their movements are usually "rhythmical and organized" and are "ordinarily
sufficiently forceful to propel the baby a short distance through the water".
So far so good.
But they don't seem to ever mention the fact that
the same study looked at other mammalian infants (opossum, rat, kitten,
rabbit, guinea pig, and rhesus monkey) and found that they behaved the
same way: "these rhythmical movements of the human infant are quite similar
to those of other young quadrupeds in water".
AAT/H proponents consistently
report only the info about human infants, and state that they react
in a unique manner, ignoring the contrary facts the study reports
regarding non-human infants, even though the info about both human and
non-human infants is reported on the same page.
Note that an older chimpanzee
was also tested and, just like older human infants, was inactive when placed
in the water.
Note too that this study found that "at no time did any baby
show himself capable of raising his head above the water level for the
purpose of breathing".
So that's the sad secret of the drowning infants;
what we actually find here is not so much "swimming babies" as infant mammals
slowly drowning without a struggle.
Let me take this lead-in to make another point about the supposedly instinctive ability of humans to swim:
It's been a common, even central, claim from various versions of the AAT/H that humans have some special, inbred, and unusual-for-primates knack for swimming. But they don't. In fact, ironically, it seems likely that swimming is one area where -- for similar reasons due to their locomotion specializations -- humans, chimps and bonobos (probably before they diverged from each other), and gorillas all independently evolved a similar trait: the relative inability to swim in an easy, natural, way that allows the animal to swim instinctively. So the 3 groups all independently lost the ability to swim instinctively. In each group it's due to their primary locomotion, knucklewalking for chimps, bonobos, and gorillas, and bipedalism for humans. The knucklewalking adaptation seems to be even worse for swimming than the bipedalism adaptation. It makes one tend to dip down headfirst, which is disastrous unless you learn to overcome it (which according to observers some few -- apparently some very few -- gorillas and chimps have managed to do), while the bipedalism adaptation makes you tend to tip back, which also helps you drown but can be overcome somewhat more easily. But both are worse by far than other quadrupedal methods, from what the swimming abilities of other primates and other mammals shows us, and contribute to the high drowning rates seen in humans, including infants, children, and adults. They make the instinctive swimming motions seen in mammals, and the ability to raise the head to breath, counterproductive.
This has been ignored by AAT/H proponents, especially hypocritical of them due to the fact that this has been handily described by Jan Wind in the volume The Aquatic Ape: Fact or Fiction?, a volume those same proponents regularly insist others read and not ignore.
Wind also made a point about the ubiquity of instinctive swimming ability in most mammals, including primates, and reported on a test where he placed a tree shrew and a macaque, neither of which had any swimming experience, in water and they both immediately swam perfectly well, quite unlike the typical human experience.
There seem to be few mammals which definitely cannot swim, or which cannot swim instinctively, although many have been erronously said to be unable (for instance I've seen it claimed erronously that rabbits, bats, sloths, and kangaroos are unable to do so). And of course there are many mammals which do not ordinarily try swimming, which makes it hard to say whether or not they could. As far as I have seen, humans and the African apes are among the very few which are known to not swim instinctively; two which cannot swim are (as far as I've seen) giraffes (they wade well enough, as you'd expect for an animal which has little trouble keeping its head out of water) and -- ironically enough -- adult hippos, which walk on the bottom but apparently cannot swim (juveniles can). The interesting thing about all of these -- adult hippos, giraffes, African ape, and humans -- is that their shared difficulties are due to mechanics -- weight and denseness in hippos and imbalance due to physical specializations in giraffes, African apes, and humans.