Susan A. Gelman's psychological study is complex and very well researched. In spite of the title, it is a book not so much about childhood as about human cognition, employing children's conceptualizations as a way of studying human reasoning at its origin.
Gelman's overarching concern is the phenomenon called "essentialism," which means, "[r]oughly... the view that categories have an underlying reality or true nature that one cannot observe directly but that gives an object its identity" (p. 3; see also 8). Essentialism, Gelman says, is universal: everyone feels that the world around us is understandable on the basis of certain categories, and moreover that these categories are "natural", in the sense that they reflect the real world, and are not invented. Second, she maintains, we believe that things are how they are, and what they are, because of "some unobservable property... the essence" (p. 7). Finally, we believe that "everyday" language (including words such as "dog" or "tree") truly corresponds to how things actually are.
Gelman's main concern is why we essentialize. Is essentialism innate, or learned? If it is innate, is it simply a necessary component of cognition in general, or do we essentialize because it is advantageous for various evolutionary purposes? Is it innate because it truly reflects the structure of the world? On the other hand, if essentialism is learned, at what point is the belief acquired, and how? And again: what purpose would it serve? Children's essentialist beliefs are thus the core of her study, for they allow us to discern, through the sometimes messy and comical process of coming to know the world around us, why it is that we perceive it the way that we do.
Her book is her defense of three assertions. First: "essentialism is an early cognitive bias" (p. 7). Children essentialize naturally, Gelman convincingly argues; which means that all children, and in fact all people, have this tendency regardless of cultures or time. This "cognitive bias" is, she says, the "requirement" of cognition - at least in "certain domains" of thought (p. 7). Second: because children attribute identity to non-observable causal factors, this means (contrary to the current assertions of many developmental psychologists) that knowledge does not proceed simply from the observable and concrete to the abstract and theoretical. Even young children seek to understand the world; they do not simply mimic others' understanding of it (pp. 5, 239, 248). Children are naturally developing and constantly correcting theories about the world as they encounter it more and more. The observable and the theoretical are "two distinct though interrelated levels" of human cognition (p. 292). Third: Gelman asserts that language profoundly shapes and reinforces the bias of essentialism, even though primarily essentialism has to do with reasoning (cognition) rather than expressing (language).
The Essential Child is not without its problems. For one, Gelman at times does not apply her own theory consistently. As an example of an "egregious essentialist error," she recounts an episode when her daughter told her that "Mommies wear dresses," even though Gelman was wearing jeans at the time (p. 294). Yet, as we have seen, she has asserted that even very young children essentialize not only on the basis of surface appearances but as the result of the interaction of outward cues and theory-based reasoning. There should be no reason to think that her daughter meant to imply that "Mommies alwayswear dresses"; and any cognitively normal child knows that (for the most part) Daddies never wear dresses. It is hardly an "egregious" error, therefore, to postulate that an important difference between Mommies and Daddies is dress-wearing, however much it may be a childish simplification and a generalization.
A second problem is the meaning of "essence" itself, as employed by Gelman. Consistent with the modern worldview that can make neither heads nor tails of the concept of a "whole," essence becomes for her merely that part of a thing that is causally or sortally responsible for the identity we assign to it. She therefore defines "essence" as that part which remains unchanging as a living organism develops, or as an unliving object fluctuates in size or state; and we cannot help but think it would perhaps be better for this reason for her to speak of "essential parts" or "essential features" rather than "essences." If, however, the thing's essence is only a part of it (and generally, an inaccessible part at that), there can be little wonder why she is of the opinion that evolutionary theory proves that essentialism is a delusion.
For it is obvious that there is no such thing as essences in the sense of "parts" of things which are shared by each and every member of a kind; and certainly there is no empirically verifiable "part" of any thing that remains unchanging throughout the duration of its existence - except perhaps the chemical composition of elements such as gold, or the DNA of an individual (e.g., pp. 139, 298). But an individual's DNA can hardly be equated with his or her "essence," unless even "essence" is not shared with other members of my species, because the DNA of any given individual is different in some respects from every other individual's DNA (there simply is no such thing as "the" human genome). But this directly contradicts a key part of the definition of an "essence," that it be transferrable from parent to offspring (p. 306). The very notion of a species, of a nature, slips through the fingers of the one who pushes this logic to its conclusion.
"Nature" in the sense of a "whole" has been the meaning of "essence" throughout human thought, even in the modern era when young children look at the world around them and discern that it is made up of "people," "dogs," "houses," "airplanes," "water," "fire trucks," and the like. That is to say: when children, and adults, posit an "essence," they are concerned precisely with wholes: this thing is a "tree." The question is never simply about some hidden and ultimately inaccessible "part." It is, "What is this thing before me, as it presents itself to me in all of its aspects?" For this reason, Gelman's book fails as a study of its intended topic: the belief in essences.
Most problematic is Gelman's ambivalence on the admittedly difficult question of the relationship between human cognition and the real world. As a psychologist, Gelman is concerned - or tries to be concerned - with human cognition, not with whether essentialism is true; she wants to avoid metaphysics (pp. 7, 8). In other words, her goal is not to discuss the actual existence of essences, but the psychological question of how people perceive the world, and why. But this delimitation proves impossible to maintain in practice. She states, for instance, that I may believe that what comes out of my tap is "water"; but as a whole, I have neither "the time or resources to check out the chemical structure of what I am drinking before I name it" (p. 301). For convenience's sake, I need not pull out my electron microscope every time I fill my glass; but the belief that I "know" that I am drinking water is for this very reason mistaken. This, however, suggests that essentialism would not be illusory were I to undertake the process of verification - which suggests in turn that it makes a great deal of difference for essentialism whether there actually is a correspondence between it and the real world, unless Gelman does not believe that there is such a thing as "water" after all.
The attempt to concern oneself only with psychology and to avoid metaphysics is shown to be doomed from the outset; Gelman proves to be more interested in the ontological implications (and foundations) of her psychology than she cares to admit. Significant in this regard is one of the opening quotes of her tenth chapter, from Douglas Medin: "Psychological essentialism is bad metaphysics,... [but] may prove to be good epistemology." But Gelman's prognosis is that essences (if they exist) remain inaccessible, and in the end, irrelevant for essentialist belief. She seems to want to assert that essentialism is a way of "knowing" the world for merely practical purposes, albeit with both advantages and dangers. But she also wants to maintain that evolutionary biology proves that essentialism does not accurately reflect the world. Were this true, essentialism would not be "knowledge"; it would be delusion. Medin's quote would then only make sense if "good epistemology" means knowing precisely nothing.
Gelman's study does prove, however, that the human person's first and original posture before the world is - universally! - dependent upon a metaphysics vastly different from the nominalism and atomism on the foundations of which the modern era was constructed. It is given to us by nature to perceive, and to seek to perceive ever more truly, form. Far from being "inaccessible" and unimportant, essence in its true sense has, in fact, everything to do with my interaction with the world. We could further say that, contrary to Medin's epistemology of utility, the universal epistemology of children is one of trust. A child moves about unselfconsciously in the world, never thinking to doubt his or her own unity, and curious and happy to encounter other entities whose unity the child likewise has no thought to doubt. A child's natural epistemology (and we were all children once) thus serves as a powerful testimony to the fact that, behind the promise of disillusionment made by evolutionary biology, inevitably lurks a profound self-alienation. It seems a legitimate question to ask whether a science that demands of us the loss of our selves is worth the price - and even more to the point, whether it can truly be called "science."