He has long stated an interest in developing a scientific semiotics (particularly biosemiotics) that would contribute to both linguistic theory and cognitive neuroscience.

[1] His 1997 book, The Symbolic Species: The Co-evolution of Language and the Brain is widely considered a seminal work in the subject of evolutionary cognition.

His approach to semiotics, thoroughly described in the book, is fueled by a career-long interest in the ideas of the late 19th-century American philosopher, Charles Sanders Peirce.

The book speculates on how properties such as information, value, purpose, meaning, and end-directed behavior emerged from physics and chemistry.

[3] Instead, Deacon argues that life- or mind-like properties only emerge from a higher-order reciprocal relationship between self-organizing processes.