Jean E. Fox Tree

Jean E. Fox Tree is a professor in the Department of Psychology at the University of California at Santa Cruz. Fox Tree studies collateral signals that people use in spontaneous speech, such as fillers (e.g. ‘you know’), prosodic information (e.g. pauses between words, the melody of a sentence), fillers (e.g. ‘uh’ and ‘um’), and speech disfluencies.

Traditionally, such phenomena were given little attention by scholars, either because they were viewed as flaws in speech to be avoided or ignored, or because many psycholinguistic studies focused on speech that was prepared in advance rather than spontaneous speech. Rather than unwanted errors, Fox Tree's research has shown that collateral signals are actually meaningful and relevant to both speaker and listener, and that removing them from speech can negatively effect comprehension.

This view counters that proposed by Noam Chomsky, the well-known linguist from MIT who regarded such utterances as errors in performance and not part of proper language. Fox Tree showed, however, collateral signals are essential to successful communication in everyday situations and are beneficial to listeners.