Open Thoughts

July 2011 archive

Bias corrected

July 28, 2011

In 1839, Samuel George Morton published what was to be a series of works on human skulls. In an amazing series of highly detailed experiments, he objectively studied the difference in cranial capacities between human populations. In this pre-Darwinian era, his systematic approach of measuring large numbers of specimens was revolutionary. In the end he had measurements of up to 1000 skulls.

With the new century, the question he was asking (whether humans had a single origin or multiple origins) faded into obscurity, along with his work. Up till 1978, when Stephen Jay Gould published a paper in Science claiming that scientists are inherently biased. His prime example was Morton's experiments, arguing that Morton's results (caucasians had the biggest brains, Indians in the middle, and negros having the smallest) were flawed. This Science paper would probably have also lapsed into obscurity except for the fact that Gould is a wonderful communicator. His 1981 book "The mismeasure of Man" was a bestseller, and people took notice of the fact that scientists were after all human.

Did Morton fudge his results?

Forward to June 2011. Because Morton made all his results publicly available, and he had maintained exquisite details of his experiments (the equivalent of open access and open source today), paleoanthropologist Jason E. Lewis, with a team of other scientists, had another look at the orignal work. It turns out that Gould didn't look at the skulls, but just read the papers. Lewis went down to U. Penn and took measurements again from 308 of the 670 original skulls. The conclusion?

Morton did not bias his results.

This amazing saga shows how important it is to question the "truth", and furthermore how important it is to keep records and materials such that the "truth" can be reinvestigated. To quote the PLoS Biology paper: "Our results resolve this historical controversy, demonstrating that Morton did not manipulate data to support his preconceptions, contra Gould. In fact, the Morton case provides an example of how the scientific method can shield results from cultural biases."