Mark Changizi is an evolutionary neurobiologist and director of human cognition at 2AI Labs. He is the author of
The Brain from 25000 Feet, The Vision Revolution, and his newest book, Harnessed: How Language and Music Mimicked Nature and Transformed Ape to Man."
Earlier this week there was a debate on the origins of music at the Atlantic between two well-known psychologists. Geoffrey Miller (author of The Mating Mind) thinks music is an instinct, one due to sexual selection. On the other side is Gary Marcus (author of Guitar Zero), who believes music is a cultural invention. Given my recent book on the issue, Harnessed, many have asked me where I fall on the question, Is music an instinct or an invention? My answer is that music is neither instinct nor invention---or, from another perspective, music is both---and this debate provides an opportunity to remind ourselves that there is a third option for the origins of music, an option that I have argued may also underlie our writing and language capabilities.
What if music only has the illusion of instinct? Might there be processes that could lead to music that is exquisitely shaped for our brains, even though music wasn’t something we ever evolved by natural seletion to process? Music in this case wouldn’t be merely an invention, one of the countless things we do that we’re not “supposed” to be doing and that we’re not particularly good at---like logic or rock-climbing. Instead, music would fit our brain like a glove, tightly inter-weaved amongst our instincts…but yet not be an instinct itself. There is such a process that can give the gleamy shine of instinct to capabilities we never evolved to possess. It’s cultural evolution. Once humans were sufficiently smart and social that cultural evolution could pick up steam, a new blind watchmaker was let loose on the world, one that could muster designs worthy of natural selection, and in a fraction of the time. Cultural selection could shape our artifacts to co-opt our innate capabilities. Cultural evolution is an old idea, but there has been a resurgence of interest in it thanks to researchers like Stanislas Dehaene and Laurent Cohen, who have studied how writing neuronally recycles parts of our visual object-recognition hardware (see Reading in the Brain). And in my research I have tried to get down to brass tacks on how culture manages to harness our brain hardware. I started with the shapes of writing, providing evidence that stroke conglomerations found in writing systems here on Earth tend to match the sorts of contour conglomerations found in nature, specifically among opaque objects (the main furniture of our terrestrial world). This was the topic of the last part of my previous book,
We can read with the efficiency of an instinct because writing got shaped like nature, thereby harnessing---or “nature-harnessing”---our visual system (see also the recent reading-baboons story). I then wondered whether culture may have used the same trick for spoken language. Just as writing looks like opaque objects strewn about, might speech sound like the fundamental auditory furniture of our terrestrial world? If cultural evolution could do this, then no specialized auditory speech-processing instincts would be needed for language. For terrestrial animals the principal source of event sounds comes from solid objects---they hit, they slide, they vibrate---and so I spent a couple years trying to work out the “grammar” of sounds found among solid-object events. In Harnessed I walk through these signature sounds of solid objects, and show that these signatures are found in a wide variety of spoken languages. Processing the sounds of speech thereby comes easy, and one wonders to what extent syntax and semantics harness our earlier hardware as well. (I have argued in my research that the large-scale organization of our language lexicon might be shaped well for our brain.) If language harnesses us, then the fact that language appears to be dripping with instinct is exactly what we’d expect, even though there would be no language instinct. Which brings us back to music. Like speech, music processing is an auditory talent. But it differs in that it is deeply evocative. My own theoretical inclinations are that emotionally steeped stimuli tend to mimic in some respect human emotional stimuli (e.g., colors are evocative because they’re found on human skin), and so I wondered, What sort of human sound might music somehow have culturally evolved to mimic? The idea has been floating around since the Greeks that music might sound in some sense like movement, and so I pushed forward for a couple years on the idea, working out dozens of regularities found in the sounds people make when moving about. And in Harnessed I provide evidence that music tends to possess these regularities: music is a fictional story of someone moving evocatively in your midst. (By the way, I’d characterize my theory as an “auditory cheesecake” variant---music is a treat for our ears and minds, but not important for survival or evolution.) Music gets into our heads because our heads evolved to be especially tuned to the sounds of human behavior. If the origins of music comes from nature-harnessing as I argue, then it will have many or all the signature signs of instinct. But it won’t be an instinct. Instead, it will be a product of cultural evolution, of nature-harnessing. And it won’t be a mere invention that we must learn. In a sense, the brain doesn’t have anything to learn---cultural evolution did all the learning instead, figuring out just the right stimulus shapes that would flow right into our emotional centers and get us hooked. Not instinct. Not invention. And, in my view, the same is true for writing and language, all via culture’s strategy of nature-harnessing.
For some related discussion between Gary Marcus and myself, see this link at G+.