The Symbolic Species: The Co-evolution of Language and the Brain. Terrence W. Deacon. W. W. Norton & Company.

The Symbolic Species: The Co-evolution of Language and the Brain Book Cover The Symbolic Species: The Co-evolution of Language and the Brain
Terrence W. Deacon
W. W. Norton & Company
July 1997

This revolutionary book offers fresh answers to long-standing questions of human origins and consciousness. Drawing on his breakthrough research and comparative neuroscience, Terrence Deacon shows that:

  • The evolution of language did not involve a language organ or instinct, and did not result simply from a larger, more complex brain.
  • Language reflected a new mode of thinking: symbolic thinking.
  • Symbolic thinking triggered a co-evolutionary exchange between languages and brains over two million years of hominid evolution – “many of the physical traits that distinguish human bodies and brains were ultimately caused by ideas shared down the generations.”
  • The grammars of the world’s languages are remarkably similar and, despite their complexity, are easily learned by young children, not because of innate grammatical knowledge but because languages have themselves evolved structural adaptations to human cognitive constraints, particularly those of immature brains.
  • The first symbolic communication evolved as the only means our hominid ancestors had to overcome the evolutionary difficulties of combining long-term sexual exclusivity, mostly in pair bonds, with cooperative group foraging, which became a critical factor with the utilization of animal foods.
  • The reorganization of the brain for language brought with it many indirect and serendipitous consequences, including unprecedented local control, unusual “innate” calls like laughter and sobbing, a susceptibility to such mental disorders as schizophrenia and autism, and a compulsion to assign symbolic import to almost every aspect of the physical world.
  • An understanding of symbolic communication allows us to reinterpret such aspects of consciousness as rational intention, meaning, belief, and self-consciousness as emergent properties of the virtual world created by symbols. It also points the way to building machines that don’t just manipulate symbols, but understand them.
  • Symbolic abilities created a species that for the first time in the history of life had access to others’ thoughts and emotions – and thus confronted an ethical dimension to social behavior.

Informing all these insights is a new understanding, based on the author’s own research and the latest findings in the neurosciences and genetics, of how Darwinian processes underlie the brain’s development and function as well as its evolution. On the road to explaining how this works, Deacon introduces us to Hoover, the world’s one and only talking seal; Sherman and Austin, two chimpanzees struggling with the counter-intuitive nature of symbols; and Kanzi, another chimpanzee, who easily acquired advanced language abilities as he observed his mother’s failure to learn symbols.

In contrast to much contemporary neuroscience that treats the brain as no more or less than a computer, Deacon leads us on a carefully grounded neurobiological expedition into a view of mind that does not reduce to soulless, clockwork mechanism, but is instead an emergent feature of a universe that is “nascent heart and mind.” This book not only provides a new clarity of vision into the mechanism of mind. It injects a renewed sense of adventure into the experience of being human.

Terrence W. Deacon is a world-renowned researcher in neuroscience and evolutionary anthropology. He conducts research in laboratories at Boston University, where he is associate professor of biological anthropology, and at McLean Hospital at Harvard Medical School. In addition to his research in brain evolution and development, he has played a significant role in the innovation of neural transplantation techniques for the treatment of human brain disorders. He lives with his wife and two children in Concord, Massachusetts.