Michael Arbib: USC Neuroscience

Human language is far more than speech and its derivatives such as writing. Human signed languages like
American Sign Language are fully expressive human languages, and speakers normally accompany their
speech with facial and manual gestures. Thus any theory of language evolution must address these integral
roles that manual signs and gestures play today. What are the capabilities of the human brain that make it
possible for humans to learn language while other creatures can not? How much structure must the social
environment offer a child to acquire language? We probe these questions by studying two sign languages of
recent vintage. Nicaraguan Sign anguage developed in just 25 years while Al-Sayyid Bedouin Sign Language
developed over at most 70 years, and are still developing. We examine the emergence and dynamics of these
languages to advance discussion of what supports society offered to allow these communities to exploit the
human brain’s readiness for language in novel ways.
http://www.bec.ucla.edu/ArbibPaper.doc