The Question of Capacity: Why Enculturated and Trained Animals have much to Tell Us about the Evolution of Language.

For more than a century researchers have used enculturated animals-those extensively trained or reared by humans-to explore the effects of learning and environment on the capacities for linguistic abilities outside of the human line. Unfortunately, due to many controversies, the findings of these studies frequently have been dismissed or outright ignored. However, experimental exploration of the capacities of nonhumans is the only option to determine which, if any, language-associated capacities are unique to humans. Researchers continue to publish findings from language projects that move our understanding forward, including descriptions of capacities, such as gestural comprehension, declarative communication, and categorization, that are frequently considered to be specific biological adaptations.