Despite the author's ambitious promise, and despite the inclusion of some elegant experiments on infants – the well-known preference studies that demonstrate a sense of "object permanence" in three-month-olds, and a lovely task in which children are introduced to the word "whisk" in connection with a picture, and go on to apply it immediately to whisks themselves, not to further images – many of the chapters give only cursory attention to child development. In a treatment of artifact concepts, three pages deal with their early acquisition; and the theory of morality is ninety per cent evolution, ten per cent sprog.
The most striking and dramatic doctrine of the book is about infant development. According to Bloom, we are "Descartes' babies" in that we are "natural-born dualists": more or less from birth "we see the world as containing bodies and souls". Among the "basic notions" that are absent only in "psychopaths […and] severely autistic children" are the recognition that "your body will change radically as you age, but you will remain the same person" and that "when you die, your soul may live on".
This is certainly impressive, if it is true: Cartesian dualism comes to us automatically, as part of the package in which we understand our own persistence through time. But it is terribly misleading as an account of what Bloom's evidence supports. His principal observation is that infants deploy quite different strategies of explanation for the activities of intelligent creatures than they do for physical goings-on. The most one could conclude from this is that we are Davidson's babies, that we make an innate distinction between the natural and human sciences – not that we accept a dualism of substance. And in fact, this weaker view is echoed in some of Bloom's more cautious formulations, according to which we have "two ways of looking at the world: in terms of bodies and in terms of souls."
Bloom cites only one experiment on behalf of ontological rather then explanatory dualism in infants, which is due to Henry Wellman:
For instance, one tale [told to young children in the experiment] was about a boy who had a cookie and another boy who was thinking about a cookie. Even three-year-olds understand the difference between a real cookie, which can be seen and touched by another person, and an imagined cookie, which cannot be.
Read as an argument for Bloom's conclusion, this passage makes an elementary mistake: it confuses the object of a mental act, which may not be a material thing because it may be something that doesn't exist, with the mental goings-on themselves.
It is possible that Bloom has simply failed to report on a wealth of evidence for his Cartesian hypothesis. But even if it is out there, that would not make the title of this book more apt: it does not argue that we are Descartes' babies; and its theory of human nature does not mainly derive from the science of the child.