Gould's claim that Morton had
mismeasured crania based on race derived from his comparison of Morton's seed - based and lead shot — based measurements, with different races experiencing different changes in their average cranial capacity between the two methods [1].
If Gould was right and Morton had mismeasured some skulls because of racial bias, we would expect
the mismeasured crania to be non-randomly distributed by population: Morton's overestimates would be concentrated on the crania of «white» people, while his underestimates would be mostly «non-white».