The late scientific icon, Stephen Jay Gould, botched and perhaps faked his critique of a racist 19th-Century scientist's skull collection, suggests a second look at his efforts.

In a 1978 Science paper, Gould (1941 - 2002) , reported that the Samuel George Morton (1799-1851), "a prominent Philadelphia physician," had mis-measured the cranial capacities of his 1,000-skull "American Golgotha" collection gathered from around the world, to suit his racist beliefs. The finding led to one of Gould's best-known books, The Mismeasure of Man, a critique of scientific racism.

"Morton is now viewed as a canonical example of scientific misconduct. But did Morton really fudge his data?," asks a PLoS Biology study led by anthropologist Jason Lewis of Stanford University. "Are studies of human variation inevitably biased, as per Gould, or are objective accounts attainable, as Morton attempted?"

So, the study team remeasured the skulls collected by Morton, now owned largely by the University of Pennsylvania Museum of Archaeology and Anthropology in Philadelphia.

Overall, they find, Morton did make mistakes in measuring skull capacity (he first stuffed them with seeds, and later lead shot to measure their brain size). But the mistakes were random. The random mistakes didn't favor any racial theory of larger brain sizes for white people over others.

"Given how long Gould's work has been criticized in this arena, I'm a little surprised that it took this long for the work to be done to write this article," says the University of Texas's David Prindle, author of Stephen Jay Gould and the Politics of Evolution. "People who dislike Gould's work will likely go on disliking him even more after this article. People who are fans of his writing will likely go on supporting his views."

Today, researchers know that larger average skull size is largely a function of cold weather:

In reevaluating Morton and Gould, we do not dispute that racist views were unfortunately common in 19th-century science or that bias has inappropriately influenced research in some cases. Furthermore, studies have demonstrated that modern human variation is generally continuous, rather than discrete or ''racial,'' and that most variation in modern humans is within, rather than between, populations. In particular, cranial capacity variation in human populations appears to be largely a function of climate, so, for example, the full range of average capacities is seen in Native American groups, as they historically occupied the full range of latitudes, say the study authors.

Morton neither manipulated his skull samples, unfairly selected which data to report, skewed results by gender, or ignored his mistakes to favor racist interpretations of his skulls, the PLoS Biology study authors conclude -- all charges made by Gould against the long-dead physician.

What's more, the researchers found Gould made some mistakes in his re-analysis of Morton. "Our analysis of Gould's claims reveals that most of Gould's criticisms are poorly supported or falsified," they conclude: