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Two Steps Forward, One Step Back.

There is much to like in Campos et al.’s (this issue) comprehensive and thoughtful target article on the psychological changes impelled by the onset of self-produced locomotion. The critical role of motor abilities in development is reestablished in the midst of an era preoccupied with infants’ precocious worldly knowledge and children’s emerging theories of mind. The complexity, indirectness, and nonlinearity of development are also wonderfully illustrated. Who would have thought that crawling promotes the understanding of referential gestures, until Campos et al. point out an obvious connection via the increase in parents’ distal prohibitions and commands? The article also draws on a wealth of evidence, showcasing all of the classic methodologies in developmental psychology, from deprivation designs and parent interviews to animal models and cross-cultural comparisons. It will be a terrific article to teach from in methods and design courses. Along with its many virtues, however, Campos et al.’s strong emphasis on locomotor experience as an agent of change seems to sharpen several distinctions that developmental psychologists have been working hard to blur. The first of these is the well-known “nature versus nurture” dichotomy, once the reason for and now the bane of the discipline’s existence. Early in the article, Campos et al. state their aim of showing that the broad-scale transition in infancy involving search for hidden objects, secondary intersubjectivity, reactions to heights, and so forth “is not necessarily mediated by maturational factors (i.e., by the unfolding of a genetic blueprint for psychological changes), but instead, is intimately linked to experience” (pp. 153–154). They go on to argue persuasively that these diverse cognitive and social acquisitions are related to experiences and attentional biases that in turn are the inevitable consequences of self-produced locomotion. Hence, once an indiINFANCY, 1(2), 225–230 Copyright © 2000, Lawrence Erlbaum Associates, Inc.