Sensitive periods in cognitive development: A mutualistic perspective

The theory of mutualism posits that general cognitive ability emerges, at least in part, due to positive reciprocal interaction between distinct cognitive abilities during development. In other words, cognitive abilities at a given developmental time point govern the rate of growth in other cognitive abilities. Moreover, this emerging field of work finds that the strength as well as the nature of these interactions differs during developmental time: In other words, there are sensitive periods when small individual differences may have especially pronounced, long-lasting consequences for cognitive development. Here I review the literature on mutualistic effects, and show how it can shed new light on sensitive periods. I do so by considering sensitive periods as periods where interactions between (cognitive) domains differ in strength and/or in kind.