Published online by Cambridge University Press: 12 August 2005
Arbib presents a reasoned explanation for language evolution from nonhuman to human primates, one that I argue can be equally applied to animals trained in forms of interspecies communication. I apply his criteria for language readiness and language (in actuality, protolanguage) to the behavior of a Grey parrot (Psittacus erithacus) taught to communicate with humans using rudiments of English speech.
1. Expression of the ZENK gene, a songbird analog to a human transcription factor, egr-1, is driven by actions of singing and hearing. Hence, it is used to form a functional map of avian brains for behavior related to both auditory processing and vocal production (Jarvis & Mello 2000).