These results falsify the claim that Morton physically mismeasured crania based on his a priori biases

Scientists Measure the Accuracy of a Racism Claim by Nicholas Wade. This is disappointing. I had a long run of reading Stephen Jay Gould's articles and books and found them erudite and entertaining. I particularly enjoyed his The Mismeasure of Man and have occassionally used his example of measuring brain capacity to illustrate the subtle influence of unconscious bias.

And now it appears that it was Gould who was biased.

Scientists have often been accused of letting their ideology influence their results, and one of the most famous cases is that of Morton’s skulls — the global collection amassed by the 19th-century physical anthropologist Samuel George Morton.

In a 1981 book, “The Mismeasure of Man,” the paleontologist Stephen Jay Gould asserted that Morton, believing that brain size was a measure of intelligence, had subconsciously manipulated the brain volumes of European, Asian and African skulls to favor his bias that Europeans had larger brains and Africans smaller ones.

But now physical anthropologists at the University of Pennsylvania, which owns Morton’s collection, have remeasured the skulls, and in an article that does little to burnish Dr. Gould’s reputation as a scholar, they conclude that almost every detail of his analysis is wrong.

“Our results resolve this historical controversy, demonstrating that Morton did not manipulate his data to support his preconceptions, contra Gould,” they write in the current PLoS Biology.

Dr. Gould, who died in 2002, based his attack on the premise that Morton believed that brain size was correlated with intelligence. But there is no evidence that Morton believed this or was trying to prove it, said Jason E. Lewis, the leader of the Pennsylvania team. Rather, Morton was measuring his skulls to study human variation, as part of his inquiry into whether God had created the human races separately (a lively issue before Darwin decreed that everyone belonged to the same species).

In his book, Dr. Gould contended that Morton’s results were “a patchwork of fudging and finagling in the clear interest of controlling a priori convictions.” This fudging was not deliberate, Dr. Gould said, but rather an instance of unconscious doctoring of data, a practice he believed was “rampant, endemic and unavoidable” in science. His finding is widely cited as an instance of scientific bias and fallibility.

But the Penn team finds Morton’s results were neither fudged nor influenced by his convictions. They identified and remeasured half of the skulls used in his reports, finding that in only 2 percent of cases did Morton’s measurements differ significantly from their own. These errors either were random or gave a larger than accurate volume to African skulls, the reverse of the bias that Dr. Gould imputed to Morton.

“These results falsify the claim that Morton physically mismeasured crania based on his a priori biases,” the Pennsylvania team writes.

Dr. Gould did not measure any of the skulls himself but merely did a paper reanalysis of Morton’s results. He accused Morton of various subterfuges, like leaving out subgroups to manipulate a group’s overall score. When these errors were corrected, Dr. Gould said, “there are no differences to speak of among Morton’s races.”

Gould was always something of a lightning rod but that was part of what made him fun to read. You felt that here was someone unconstrained by convention, willing to tackle anything and bringing an inspiring breadth and depth of knowledge to every inquiry.

So I am left a little disillusioned to find a hero's reputation tarnished. What is particularly striking to me though are two items. I do not recall being aware at the time of reading The Mismeasure of Man, that Gould's analysis was not based on a physical replication of Morton's measurements. I think I must have assumed that he did. That assumption combined with his credibility made for a powerful argument. Back to the old time religion - Trust but verify even from trusted sources, Never assume, etc.

The second striking item is the time frame. The Mismeasure of Man was published in 1981, excited much comment, was quite influential and among the reasons for its influence was the striking claim of Gould that Morton had been subtly and unconsciously influenced by his own biases. 31 years later, someone actually tests the data by reproducing the experiment.

Sometimes it seems as if we don't deserve the scientific method because we are so casual about it. Gould had a good story and we ran with that for a whole generation before anyone bothered to validate the data - Step 1 for any significant claim.

Oh dear.

UPDATE: This article, When Bad Theories Happen to Good Scientists by Matt Ridley would seem to suggest that the 31 year lag between proposition and testing might be because we want to believe that in the olden days, scientists were biased and racially prejudiced. When Gould came along with a good story confirming that assumption, we allowed our confirmation bias to play so well that we never got around to testing Gould's assertion for thirty one years. Someday we will learn to be humble. But not today.