Friday, September 09, 2005

The "Science Marches on in My Name" Fallacy

Ernie and I aren't particularly fond of NRO writer John Derbyshire. He's supposed to be a conservative, but he's really a right-wing Social Darwinist who takes a majoritarian stance towards issues such as abortion and embryonic stem cell research. Of course, this label wouldn't bother him in the least, and my aim here is not to attack his views; it's to describe a particular fallacy that Derbyshire commits now and again. Let's call it the "Science Marches on in My Name" fallacy. To commit this fallacy, follow these easy steps:

  1. Find a scientific study that seems to support one of your political or philosphical beliefs.
  2. Take that study at face value and accept the truth of its conclusion as a fait accompli.
  3. Now conflate the truth of your belief and the truth of the study's conclusion.
  4. Finally, now that your belief is allied with Holy Science, sound a triumphalist note about how Holy Science will vanquish its enemies and crush the forces of ignorance and superstition. You might even sing a hymn at this point.
What am I talking about? Take a look at this proposition:
Intelligence in humans is distributed in such a way that levels of intelligence differ not only among individuals but among racial groups as well, and this difference has a genetic basis.

This proposition is obviously controversial, but it is also contingent; it might be true, or it might be false. Either way, however, it is not obviously true right at this moment. It has not been established with any degree of scientific certainty.

Nonetheless, Derbyshire and other right-wing Darwinists take the proposition for granted. Hence the mere possibility that scientific research supports it is enough for them to declare victory. For example, Derbyshire points to a recent study suggesting that among geographical populations there is a non-random distribution of two genes responsible for brain size. Despite the fact that scientists urge caution about the study and point out that there may not be a correlation between brain size and intelligence, Derbyshire blithely declares it to be a well-known fact that:

Evolution, including brain evolution, did not proceed in precisely the same direction, at precisely the same rate, in every human group, in every region and environment.

Moreover, he draws a philosophical-political conclusion: the "blank-slate" view of human nature is false, and we shouldn't base social policies on that view. Indeed, it doesn't even matter if the study passes peer review, because similar studies in the future "won't all fail on peer review."

That's where the fallacy comes in. Derbyshire holds to the above proposition, and he just knows that science is going to vindicate it some day. Now I don't care whether the proposition is true or not; my point is that it is a contingent proposition that is not obviously true given our current scientific knowledge. Maybe science will further support it, and maybe science won't. But the direction that science goes can't be dictated in advance by one's philosophical and political prejudices. To do so is to misappropriate science.

1 comment:

Bill Ramey said...

Gould was indeed a critic of the notion that human brain size correlated with human intelligence. So in "Broca's Brain" he describes and criticizes a Victorian scientist who thought he proved the intellectual inferiority of women by showing that they have smaller brains.

Gould also hated the drawing of grand conclusions from singular empirical facts, a tendency that put him at odds with sociobiology. And that's also my beef with Derbyshire.