Terrence Deacon is an American anthropologist (Ph.D. in Biological Anthropology, Harvard University), currently Professor of Biological Anthropology and Linguistics at Berkeley. Prior to coming to Berkeley, Prof. Deacon taught at Boston University and, prior to that, at Harvard University.

Prof. Deacon's theoretical interests include the study of evolution-like processes at multiple levels, including their role in embryonic development, neural signal processing, language change, and social processes, and focusing especially on how these different processes interact and depend on each other. He has long stated an interest in developing a scientific semiotics that would contribute to both linguistic theory and cognitive neuroscience.

Deacon's research combines human evolutionary biology and neuroscience, with the aim of investigating the evolution of human cognition. His work extends from laboratory-based cellular-molecular neurobiology to the study of semiotic processes underlying animal and human communication, especially language and language origins . His neurobiological research is focused on determining the nature of the human divergence from typical primate brain anatomy, the cellular-molecular mechanisms producing this difference, and the correlations between these anatomical differences and special human cognitive abilities, again, particularly language.

He plans to focus his future research on isolating elements of the developmental genetic mechanisms that distinguish human brains from other ape brains, and attempting to study the cognitive consequences of human brain differences using in vivo brain imaging.

His 1997 book, The Symbolic Species: The Coevolution of Language and the Brain is widely considered a seminal work in the subject of evolutionary cognition. His approach to semiotics, throughly described in the book, is fueled by a career-long interest in the ideas of the late 19th-century American philosopher, Charles Sanders Peirce.