One author out of the bunch this week stood as an outlier to me: Professor Barrett, and not just because of the piece’s title. Deacon, Donald, and Renfrew seem to agree on the same basic progression, while Barrett seeks to upend most of it and raise some broader questions in the process. (Wong, meanwhile, tries to give everyone a voice.)
At the heart of Deacon’s hypothesis about what sets humans apart from the rest is what he calls the “core semiotic innovation.” He also calls this language. The evolution of the brain did not drive the development of language. Somehow the ability to make meaning, the basis for language, hit the scene, and after that brains and language co-evolved to become more complex. He gets relatively specific with this (icon-index-symbol progression), but the “critical learning threshold” came between indexes and symbolic reference. This jump allowed humans to start building a web of new meanings about things that already hold meaning, like words formed by indexical correlations. This web is formed in a special part of the brain—in the prefrontal cortex—Deacon argues.
Donald wants the focus to be on cultural networks, but he doesn’t seem to disagree with this broad-brushstroke, symbolic-reference-as-lightning-bolt progression. He argues that humans can “learn, vary or refine any action” through practice and improvement, and that this ability eventually led to language. Then things really took off. Memories could be stored externally and shared between generations (Wong describes this as a “watershed event” when detailing the view). Cultural networks made up of the “cognitive resources of many individuals” blossomed, and these shared resources conferred significant developmental advantages on their possessors. Renfrew says Donald’s explanation is missing something and adds the Symbolic Material Culture phase after mimesis, before humans developed language. During that stage, artifacts held meaning and conveyed information, driving development.
Barrett takes issue with a lot of this. He seems to reject the ideas that some sort of cognitive and symbolic revolution happened and that there’s an “agent that is responsible for establishing” what representations/experiences actually represent. He rejects the notion that the mind has specialized processing regions—not a fan of Deacon’s prefrontal cortex, I suppose. (He also describes other ideas that run contrary Deacon et al, such as Dennett’s reasoning that consciousness has little to do with the psychological and that it evolved out of the way the brain works.) Barrett’s bottom line, meanwhile, seems to be that humans developed what we now consider to be symbolic capabilities because of sense-driven needs shared between organisms (I confess I don’t quite grasp the specific mechanisms here), not because of some sudden move to ascribe meaning to something.
I scribbled down a number of notes-to-self about computers while I was reading all this. It seems there are similarities between some of these principles and the development of computing, and that perhaps some of the former drove the latter. The concept of indexes in databases jumps out, for instance. If I understand it correctly, entries in an index have a value, and those values are correlated to related records. Those values and records are then manipulated by outside forces. I also found myself wondering, if meaning evolved as Barrett says it did, does that mean that AI that truly replicates human intelligence will be impossible to develop? It’s also interesting to think about the development of technologies in general as compared to the selection of language, which Deacon describes.
Barrett, John C. “The Archaeology of Mind: It’s Not What You Think.” Cambridge Archaeological Journal 23, no. 01 (2013): 1-17.
Deacon, Terrence W. The Symbolic Species: The Co-evolution of Language and the Brain. New York: W. W. Norton & Company, 1998.
Donald, Merlin. “Evolutionary Origins of the Social Brain.” In Social Brain Matters: Stances on the Neurobiology of Social Cognition, edited by Oscar Vilarroya and Francesc Forn i Argimon, 215-222. Amsterdam: Rodophi, 2007.
Renfrew, Colin. “Mind and Matter: Cognitive Archaeology and External Symbolic Storage.” In Cognition and Material Culture: The Archaeology of Symbolic Storage, edited by Colin Renfrew, 1-6. Cambridge, UK: McDonald Institute for Archaeological Research, 1999.
Wong, Kate. “The Morning of the Modern Mind: Symbolic Culture.” Scientific American 292, no. 6 (June 2005): 86-95.