He is the author of a dozen books, mostly for general readers, about brains and evolution. The latest is A Brief History of the Mind: From Apes to Intellect and Beyond. Out in paperback is A Brain for All Seasons: Human Evolution and Abrupt Climate Change, about paleoanthropology, paleoclimate, and considerations from neurobiology and evolutionary biology, which won the 2002 Phi Beta Kappa book award for science. His book with Derek Bickerton, Lingua ex Machina: Reconciling Darwin and Chomsky with the Human Brain, is about the evolution of structured language.
His research interests include the recurrent excitatory circuitry of cerebral cortex used for split-second versions of the Darwinian bootstrapping of quality, the four-fold enlargement of the hominid brain during the ice ages, and the brain reorganization for language and planning during "The Mind's Big Bang" which occurred about 50,000 years ago, long after our brains had reached their current size.