Comprehension and Production in Early Language Development

Savage-Rumbaugh and her colleagues have provided us with yet another ground-breaking investigation into the linguistic abilities (or "quasi-linguistic abilities " — see below) of our nearest phylogenetic neighbor, the chimpanzee. Their monograph begins with some brief but useful reviews of the primate language literature, and the literature on early comprehension and production of language in human children. The authors document the peculiar bias toward production and the relative neglect of comprehension that have characterized the child language literature, and they ask a perfectly reasonable question: If we want to understand what an organism knows about language, isn't comprehension a better place to start? And if we want to compare knowledge of language in two related species, how can we draw any firm conclusions if our work is based exclusively on what the animal can produce?