Mechanisms of Cognitive Development: Domain-General Learning or Domain-Specific Constraints?

The issue of how people acquire knowledge in the course of individual development has fascinated researchers for thousands of years. Perhaps the earliest recorded effort to put forth a theoretical account belongs to Plato, who famously advocated the idea that knowledge of many abstract categories (e.g., ‘‘equivalence’’) is innate. Although Plato argued with his contemporaries who advocated the empirical basis of knowledge, it was the British empiricists who most forcefully put forth the idea of the empirical basis of knowledge, with John Locke offering the famous ‘‘tabula rasa’’ argument. The first comprehensive psychological treatment of the problem of knowledge acquisition was offered by Piaget (1954), who suggested that knowledge emerges as a result of interactions between individuals and their environments. This was a radical departure from both extreme nativism and extreme empiricism. However, these ideas, as well those of empiricist-minded behaviorists, fell short of providing a viable account of many human abilities, most notably, language acquisition. This inability prompted Chomsky to propose an argument that language cannot be acquired from the available linguistic input because it does not contain enough information to enable the learner to recover a particular grammar, while ruling out alternatives (Chomsky, 1980). Therefore, some knowledge of language must be innate to enable fast, efficient, and invariable language learning under the conditions of the impoverished linguistic input. This argument (i.e., known as the Poverty of the Stimulus argument) has been subsequently generalized to perceptual, lexical, and conceptual development. The 1990 Special Issue of Cognitive Science is an example of such generalization. The current Special Issue on the mechanisms of cognitive development has arrived exactly 20 years after the first Special Issue. In the introduction to the 1990 Special Issue of Cognitive Science, Rochel Gelman stated: