Myrtle McGraw's Unrecognized Conceptual Contribution to Developmental Psychology

In the late nineteenth century and through much of the twentieth century, the notion of the early developmental autonomy of motor behavior pervaded behavioral embryology and the developmental psychology of infant behavior. In the midst of this predeterministic climate of opinion concerning motor development, Myrtle McGraw briefly and tentatively broached the probabilistic epigenetic notion of a bidirectional or reciprocal relationship between structural maturation and function, whereby structural maturation of the nervous system is influenced by functional activity as well as the other way around. Myrtle McGraw thus anticipated our current understanding of the role of experience in the cortical and motor maturation of infants in the first year of postnatal life. It is all the more remarkable that she made this contribution when the theoretical climate of opinion was epitomized by predeterministic epigenetic thinking. In the same vein, McGraw's second unrecognized contribution is her clear formulation of a suitably flexible critical period concept in 1935, one that is consonant with our current understanding.