Sunday, April 15, 2012

And the Walls Came Down, bah bum...



…. all the way to Hell... (Traveling Wilburys' Tweeter and the Monkey Man, 1988)

I finished a book a few months back, Reading in the Brain, by Stanislas Dehaene. It was an eternal slog, begun in the brief moments of respite I had while fulfilling my duties as summer school director in the district where I work, and continued through daily, 15-minute silent reading times throughout the school year. It was a tedious book, in some regards, at least to a lay person such as myself, far more interested in the implications of his findings (for reasons of both personal and professional curiosity), than in the minutia of how he came to them.

Fortunately, the reader's patience was well-rewarded. Because the implications of Dahaene's findings are both fascinating and profound. He begins from a readily observable fact- children acquire spoken language automatically, with almost no direct instruction, yet learning to read requires years of intensive, deliberate instruction and practice. Clearly, the brain is primed to acquire one of these skills, and the other can only be managed with sustained, deliberate and, often, frustrating effort. As the father of an emerging reader, and as a professional charged with teaching reading to a population whose background is one of almost universal illiteracy, I can attest to the significant difference between the effort required to master these two distinct aspects of language, as I am sure can many others.

The readily observable differences in the “acquireablility” of these two modes of language usage leads Dehaene to posit, without having to make too much of a leap, that while we have evolved to use spoken language, (and all the evidence suggests it has been in use by Homos for hundreds of thousands of years, if it does not pre-date our genus altogether), reading is a relatively new cultural artifact, a mere few thousand years old, which evolution has certainly not had time to adapt our brains to. Thus, while the mechanisms for spoken language are built into the brain, to acquire reading, one must co-opt and modify other parts of the brain which weren't “designed” for reading at all.

But which parts? Well, this is what Dehaene, as a neuroscientist, is most interested in, and what he devotes most of the book to. However, for the lay reader, a lot of hard science concerning neurons and synapses and Broca's region and the prefrontal cortex gets a little wearisome. So for our purposes, only two of his finds concern us. First, that reading in any language utilizes almost exactly the same regions of the left hemisphere of the brain. (In a healthy, expert, reader- though he spends a lot of time on what happens when a reader isn't these things.) This is true in alphabetic languages, such as English or French, as well as symbolic languages, such as Chinese and Japanese. Secondly, the neurons that the brain co-opts for the purposes of reading, in an expert adult reader, are stolen from use from other visual areas. In short, no matter what language a child is learning to read, the brain co-opts neurons from other visual processes to do so.

It's the answer to the next question that I found particularly fascinating- what parts of the brain's visual toolbox are the co-opted for reading? Dehaene suggests that, over time, languages, especially alphabetic ones, have evolved to be readily identifiable and accessible to the primate brain (more on other primates later). In other words, the letters of the alphabet, probably the most efficient form of written communication in the world, consist of shapes that would have stood out in a primate's three-dimensional visual brain. It is easy to see, when looking at letters such as X, O, I, S, T, Y and practically any other, shapes in the 3D visual field which correspond to these letters. More complex letters, such as R, are more likely compounds of several easily recognizable shapes.

This is part of his answer. The other part points to evidence that people who live in hunter-gather societies, and who are illiterate, are able to “see” signs in the natural world, in the context of hunting, for example, that a literate person, with any amount of training, simply can't see. Some of this evidence is circumstantial, and anecdotal, but it nevertheless makes a lot of sense, and is backed by a fair amount of harder evidence. Learning to read necessarily means losing the ability to see other aspects of the visual world, as the neurons that are normally designated for those aspects are co-opted for the task of reading.

So what do neurons have to do with an 80s supergroup? This. A study thatshows how readily adaptable the primate brain is to the act of visualrecognition of letters. Coming across this article this morning, it occurred to me just how well this would have fit into Dehaene's work. But there are larger implications for findings such as these.

The wall between us and other species is coming down. Almost daily, one can point to a new piece of evidence that something we once thought of as exclusively human is actually a trait or ability we share with many other species, often our cousins the other primates, but others as well. Some of the implications of this are obvious, others are more subtle.

One implication is so obvious that I barely need to mention it; that as it becomes evident that we differ from other species merely in certain degrees, not in any kind, there is less and less (read: no) reason to speculate that we have some divine or eternal soul instilled in us to explain our mental abilities. Our brains are just the same as any other brains on the planet, just very highly adapted for the particular purpose of negotiating the complex social interactions that come with being human, among other things.

The crumbling of this wall also has significant, I would say devastating, consequences for those who worship “culture” or “the social” as the ultimate arbiter of all human experience. The adherents of this faith, who refuse to abandon the patently absurd notion that only Nature or (for them) only Nurture can explain human behavior, rely on this fictitious distinction between human beings and other animals as the jumping off point for all of the subsequent branches of their “theories:” Marxism, radical feminism, race theory, queer theory, etc., as well as much fruitless work in anthropology, psychology and other social "sciences," when they choose to ignore the origins of the very subject they are studying- human beings.

Science moved beyond this argument long ago, recognizing that while our genes endow us with possibilities, culture determines a great deal of their manifestation. Reading, as Dehaene demonstrates, is a prime example of this. Our evolutionary history has given us brains that, with the right instruction, are capable of learning symbolic written language. In every healthy human being who acquires this skill, it occurs in the same place in the brain, is acquired at roughly the same rate, moves through the same stages and transforms our brains in the same predictable way. This is genes. What language we learn to read, and, indeed, if we learn to read at all, this is culture.

This is why the article linked above caught my attention. Because in this study of baboons, the clear beginnings of the eventual human tool of reading are manifest. The most logical explanation for the fact of our shared ability with baboons to recognize with accuracy the same written visual shapes is that a common ancestor of ours also had this ability. (The only other explanation that fits the evidence is that it evolved separately, which is unlikely in two so closely related species.) This pushes the emergence of all the underpinnings of “culture” way back into our evolutionary past, far back beyond the emergence of our species. (Of course, this is not the only evidence for that; the increasing evidence for morality, communication, tool use, self-consciousness, and even “culture” in other, non-human, species are all part of this argument as well.)

As mentioned above, the sciences that are concerned with these questions, biology, evolutionary theory, genetics, neuroscience, etc. have long moved past the Nature/ Nurture question, to the obvious answer- Both. This is also true of the leaders in any field that had traditionally been on the Nurture side of the debate: psychology, linguistics, anthropology, etc. However, there are still a large number of students at less-than-leading universities being taught by professors who are stuck in the middle of the previous century, and this trickles out into the population at large. I'm not entirely sure why it is so essential to some in the social sciences to resist the truce that the hard sciences declared so long ago. Perhaps it is a (justified) fear that many of their traditional methods of inquiry will be exposed as faulty, or rather that acknowledging that this occurred long ago will be embarrassing.

Or perhaps it is from the (totally unjustified) fear that accepting evolution's inescapable role in shaping aspects of our nature means that any and all of those aspects are “right” because they are “natural.” This is largely due to what might be called the “Whole Foods Fallacy”- the pervasive notion in our society that what is “natural” is automatically “good.” This is so obviously erroneous that it can be dismissed with two words- scorpion sting.

Despite the fact that there is no more intrinsic connection between what is “natural” and what is “good” than there is between “might” and “right,” this doesn't stop most people's brains from making the false connection between what they value in what they put in their body to and the wider world as a whole. And this leads people to a difficult position- if what is “natural” is “good” but this guy is saying things like male sexual opportunism are “natural” he must be saying that they are “good.” Ergo- either I must accept something which I find distasteful as “good” or I must dismiss it as not being “natural.” Despite the fact that choosing the later option requires dismissing mountains and mountains of evidence, many people choose this over letting go of one, simple, false tautology.

Of course, what is missed by those who choose option A above, the dismissal of the evidence uncovered by natural science, is the root of their own disgust. How is it that we are all almost universally disgusted by philanderers, yet somehow “culture,” and culture alone, is also responsible for their very existence, and if we could just change our “society” they would all go away? Or murders? Or rapists? Or racists? Or religious fanatics?

The evolutionary explanation does not run into this contradiction. In an evolutionary context, it is very easy to see how an individual can be inclined to act in a way that is counter to the social norms of their tribe, norms that they themselves would reinforce if someone else was the cheat. But enough digression...

At this point, it is impossible to ignore, without intentional self-deceptive blindness, the fact that we homo sapiens are more similar to other species than we are different. We share with them concepts of right and wrong, fairness, the in- group/ out- group dichotomy, tool use, mathematics, language, communication, culture. It is no longer possible to build a wall between “us” and “them” and claim that what is true of them, is not true of us, or vice versa. They have instincts, so do we. They have the capacity to learn, and so do we, just to a much greater degree. Our capacity for culture and learning has been driven by the frenzy of sexual selection, to the point where our brains have a lot of bells and whistles so extravagant that they seem almost a different beast than those of the beasts, but this is merely one of the illusions created by having the human equivalent of a peacock's tail in your skull. (I count 17 mixed metaphors in that last sentence...)

We no longer get to use “souls” or “culture” to pretend that we are playing by different rules than any other species on the planet. Our evolved ability to transmit culture- ideas, both true and false, our learnings about the natural world, stories of our own histories- to one another, across both space and time, has made us very, very good at playing this game, and made some of the rules other species have to concern themselves with almost irrelevant. But most of those rules are still those same concerns that trouble our minds on a minute-by-minute basis: finding dinner, finding mates, acquiring status, protecting it, raising offspring.

It is honestly silly, at this juncture of our understanding of the natural world, to continue to act as if our minds were somehow implanted in us from On High, regardless of what you wish to name the source. We scratched and clawed our way out of a primordial puddle, just like the rest of the gang.

Let's stop lying to ourselves about it.