Monday, January 09, 2006

Pinker Peeves

I’m about 50 pages into Steven Pinker’s The Blank Slate. Great stuff. But disagreement is interesting and agreement is boring, so I’ll focus my comments on points where I think Pinker goes astray.

First, Pinker, like so many before him, slanders the 19th century philosopher Herbert Spencer by saying he was a Social Darwinist who opposed all charity: “… Herbert Spencer wrote that do-gooders would only interfere with the progress of evolution if they tried to improve the lot of the impoverished classes and races who were, in Spencer’s view, biologically less fit” (15-16). This is a complete mischaracterization of Spencer’s position. Read Roderick Long’s excellent defense of Spencer against these scurrilous charges here. Protagoras reacts against the same passage in Pinker, and links to a couple more essays by Long.

Second, in making the case that the “unified self” is a myth, Pinker points to studies of people whose brain hemispheres have been separated by severing the corpus callosum. In such cases, the two halves of the brain think and act separately, sometimes contrary to each others’ wishes. More interestingly, Pinker notes, the left hemisphere will construct bogus rationalizations to explain the behavior of the right hemisphere:
For instance, if an experimenter flashes the command “WALK” to the right hemisphere (by keeping it in the part of the visual field that only the right hemisphere can see), the person will comply with the request and begin to walk out of the room. But when the person (specifically, the person’s left hemisphere) is asked why he just got up, he will say, in all sincerity, “To get a Coke” – rather than “I don’t really know” or “The urge just came over me”… (p. 43)
Okay, now that’s fascinating: the hemispheres perform different functions, and weird stuff happens when the hemispheres can’t communicate. But does this experiment really show, or even imply, the absence of a unified self? Only for the person whose hemispheres have been severed, as most of ours have not! One obvious interpretation is that the corpus callosum performs an integrative function in normal human beings. Cutting the corpus callosum and then citing the resulting inconsistent behavior as evidence against the notion of a unified self is not unlike unraveling the threads from a baseball and citing the ball’s coming apart as evidence against the notion of a unified baseball.

To be clear: I’m not necessarily saying that there is a unified self. I’m just saying the experiment discussed doesn’t show it.


Matt McIntosh said...

The thing you have to understand is that Pinker is in a very tricky place. He's constantly having to walk the tightrope of being willing to voice truths that many find unpleasent while maintaining his cred as a liberal. (Though I'm pretty sure he's liberal in the classical sense.) This balancing act occaisionally requires the knocking down of bogeymen in order to show what an evenhanded and reasonable guy he is. I just take it with a pinch of salt and carry on. Frankly his jokes are far more troubling.

As for the self, I have to recommend Daniel Dennett's essay on "The Self as a Center of Narrative Gravity". It clarified my thinking on that particular issue, as Dennett is wont to do.

Michael Yuri said...

I agree that the severed brain experiments don't alone disprove the unified self, but they do help to expose the powerful rationalization processes that are built into the brain. And these processes do undercut the unified self (along with certain conceptions of free will).

Along the same lines as Mr. McIntosh's comment, take a look at Pinker's defenses of various scientists who have been attacked for supporting the idea of human nature. He invariably cites the fact that they are political liberals as a defense against the charge that their science is corrupted by evil motives. Now, maybe this is an effective reply to liberal critics who view human nature as some sort of conservative plot, but I have to wonder what he would have said in defense of a biologist who is an outspoken conservative.

In any case, far more important than the actual science presented by Pinker in the Blank Slate are the arguments against a certain kind of moral thinking. If this fact is empirically true, it necessarily implies certain moral conclusions, and since these moral conclusions are abhorrent, we must refuse to believe this could be empirically true. Pinker does a good job of illustrating how the moral conclusions just don't follow from the factual premises.

Glen Whitman said...

I understand that Pinker has to establish some not-a-racist cred before saying the things he wants to say. But still, I wish he'd find a better strawman. Spencer doesn't deserve the shabby treatment.