WHAT'S GOING ON IN THERE?

This guided tour of “the wrinkly universe inside each child’s head” will fascinate most readers, but some may find themselves lost amid its complexity. In an era in which genes are given most of the credit for shaping our destinies, Eliot, a neuroscientist and mother of three, is especially interested in the other half of the development equation—“neural plasticity,” or, in layperson’s terms, how the brain is literally molded by experience. The book begins with an exhaustive survey of prenatal influences on the brain, including the experience of birth itself, and then takes us through the brain’s maturation, beginning with senses like touch, taste, and smell, which evolve in utero. Then Eliot explores the more gradual development of vision, hearing, motor skills, language, and social/emotional intelligence. Throughout, Eliot emphasizes that the brain operates according to a ruthlessly Darwinian principle: “Use it or lose it.” For most brain functions, Eliot asserts, there is a critical period in which “synapses that are rarely activated—whether because of languages never heard, music never made, sports never played, mountains never seen, love never felt—will wither and die.” Sometimes Eliot’s erudition overwhelms the reader; the book is longer than it needs to be, largely because the author bombards us with information on obscure syndromes and the like. Though Eliot occasionally writes a paragraph that reads like it came from a medical textbook, her prose is generally quite graceful, and her neuroscience-based advice to parents sometimes bucks current trends. She advises, for example, that children should not delay kindergarten, arguing that holding them back stunts rather than aids their natural cognitive development. Eliot also explains, among other things, why young children crave sweets and fats, why preschoolers can’t control themselves, how male and female brains differ, and how a simple “marshmallow test” can help predict later achievement. An engrossing, challenging work that more than answers the question its title raises. (For two other studies of earliest childhood development, see John Bruer, The Myth of the First Three Years, p. 1010, and Alison Gopnik, et al., The Scientist in the Crib, p. 1016.)