The program for this week, in our favorite radio program, In OurTime on BBCRadio 4 (applauded recently in The New York Times, and The London Review of Books, so clearly we're not alone!), is about the infant brain. Three psychologists discuss the history of modern ideas on how the brain works and develops, as an infant grows towards fully functional status.
The discussion contrasts a complete tabula rasa (blank slate) view that the infant learns everything from experience, to a totally nativist view that everything is built in. The former was advocated by Jean Piaget, the latter by Noam Chomsky. The discussants went over many intriguing experiments that have been done.
Clearly the way the brain actually develops is in the middle somewhere: the brain has regions that are dedicated to or specialize in some function, such as processing retinal images from the eye, or verbal sounds, or smells. Some parts of the brain regulate things like heartbeat and blood pressure, or secrete hormones. Except when adaptively relocating in recovery from injury, these seem at least generally to be in similar places in different individuals. That is a kind of functional hard-wiring, but it's very generic. It is a regionalization of areas that are set up, so to speak, to learn from experience--to learn sounds, language, the way animate and inanimate objects behave, and so on.
In interesting and important ways, this contrasts sharply with the dream of Darwinian psychologists and similar schools of thought, that want to be able to pry (rather pruriently, we might say) into a person's brain and claim the ability to see what they're really like, rather than how they fancy themselves to be.
The need to find a selective or even essentially deterministic explanation for the evolution of everything and anything mental is strong in our current culture, even if it's manifestly naive. If we are hard-wired for anything, overall, it is not to be hard-wired any more than was necessary. Humans are par excellence the learning and assessing organism, not one pre-programmed for our various tasks and traits. Pre-programmed to be able to scope out a new situation and figure out how to respond to it. That's what human beings are.
This is also the most parsimonious (simplest and easiest to explain) view of the human mind, if one feels a need for a selective explanation: if you were too rigidly hard-wired, you got caught by surprise and eaten at an early age! You didn't need countless specific selective adventures to weed out vagueness in any and every aspect of your thought. But it's harder to understand neurologically how unprogramming evolved than the 'genes-for' kind of dream. It also isn't as sexy and media-genic a view. Unfortunately, in our society oversimplified determinism and darwinism seems to be the order of the day.
In addition, the anthropocentric explanations of brain function are undermined by the fact that psychologists have shown that many of our traits are found in all sorts of other species, at least of mammals. Things found in dolphins and hedgehogs do not need a human-specific, much less a recent-evolutionary explanation. Such explanations are redundant, not parsimonious--not good science.
How the ability to recognize simple phonetic (sound) contrasts and the like, that is present in other species, led to our ability to build language, symbolic behavior, and all that goes with it, is the core question. Very interesting, but very hard to answer.