Most of what I know isn’t in my head. It’s out there in my books. I know how to do a lot of integrals in calculus, for example. But, really, what I mean by that is that I know where my book of integrals is, and I know where in the book any particular method is. I know all that stuff in all those books in my house because I can find my way there.
Books in a bookshelf possess lots of visual cues, so I can quickly find my way to the right book — “Oh, it’s on the bottom left of the shelf by the window in the living room, just below that big blue art book.”
And once I find the book, when I open it up I can use visual cues within it to find my way to the right page. After all, it’s not as if I remember the page number. No, I remember roughly where it is in the book, roughly what the page looks like, and roughly what the surrounding pages might look like. Pages in a book might not initially seem to have a look, but they very often do. There are often figures, or tables, or unique and recognizable features to the way the paragraphs are aligned. These visuo-spatial cues guide me further and further along to the goal, the piece of my knowledge out there in my library.
Mess with my library and books, and you mess with my brain.
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.