I had already known that the number of human chromosomes had been incorrectly reported as 48 (it’s actually 46), and that observers maintained that number for decades, seeing what they expected to see. I’ve used it as an example for years to tell students to clear their heads of preconceptions when making observations, trust what you see, and report your measurements as accurately as you can, because this tendency favoring confirmation bias can corrupt science surprisingly easily. It sounds like a relatively benign example: oops, early investigator makes a mistake counting chromosomes (I’ve done some chromosome work, it’s easy to do), and the initial observation gets perpetuated through the literature until superior techniques make the correct value obvious. Ha ha, don’t do that.
Now Dan Graur digs into the details of the mistake, and it turns out to be a goddamn horror story. There are more lessons here than I thought.
The guy who made the mistake was named Theophilus Painter, and he seems to have stumbled upwards throughout his career by being a terrible person.
The first horror: the specimens he used to make those initial chromosome counts were human testicles lopped off prisoners in an asylum. They were castrated for the crime of excessive masturbation. The methods discuss some grisly details I really didn’t need to know.
“The material upon which this study is based was obtained from three inmates of the Texas State Insane Asylum through the interest and cooperation of Dr. T. E. Cook, a physician at that institution. Two of these individuals were negroes and one was a young white man. In all three cases, the cause for the removal of the testes was excessive self abuse… The operation for the removal of the testes was made, in all three cases, under local anesthesia. An hour or two prior to the operation, the patients were given hypodermic injections of morphine in order to quiet them. This was followed by local injections of Novocain in the operating room. None of the patients exhibited any interest or excitement during the operation, nor did they show any signs of pain except when the vas deferens and the accompanying nerves were cut. One of the negroes went to sleep during the operation.”
Yikes. I guess mutilation of your patients was a routine practice in 1923. No big deal, Negroes don’t feel pain.
The second horror: as you might guess from the passage above, the whole affair was soaking in racism. Painter got the same erroneous chromosome count from all 3 of his victims, but always reported the count separately for his black and white subjects. There may also have been confirmation bias in Painter’s work, because more recent examination of his slides, which still exist, reveal that his methods were a cytological mess and it’s difficult to count chromosome numbers from them at all.
The third horror: Painter later got appointed to the presidency of the University of Texas because he was a reliably negligent creature who would happily turn a blind eye to blatantly discriminatory admission policies, and would allow segregation to continue.
Read Graur for all the details. I’m just dismayed that a point I’ve always used casually as an example of a simple error with long-term consequences is now going to have to be presented as a deeper point about bad science being used for evil. Oh, well, students should know how genetics can be misused for wicked purposes, and here’s yet another case.