15 June 2011

Personal bias: the blind spot of science

Science is indisputably the best tool for us to acquire knowledge about reality, both its contents and mechanisms. Science’s efficacy is its own validation; whether through technology or new insight into the true nature of things, our lives are tangibly affected by the processes and products of science. This is an observation that only a die-hard po-mo theorist or committed supernaturalist would challenge.

But this acknowledgement of science’s preeminence as a path to truth does not mean that science is flawless. Science is carried out by people, and people are not perfect. The subjective beliefs of scientists can, unfortunately, contaminate the objective purity of the scientific process. A recent paper published in the journal PLoS Biology, ‘The Mismeasure of Science: Stephen Jay Gould versus Samuel George Morton on Skulls and Bias’, by Jason Lewis et al, reveals how an eminent scientist, in his attempt to debunk the work of another scientist as being tainted by personal prejudice, ironically succumbs to personal prejudices of his own.

In his 1981 book The Mismeasure of Man, the late paleontologist Stephen Jay Gould set out to discredit the ideas of race and intelligence that he found appallingly bigoted and incorrect. Gould’s primary target was the 19th century racial scientist Samuel George Morton, who enjoyed a great reputation in his time for his somewhat macabre studies of the differences – chiefly in intelligence – between ‘races’. In his book, Gould essentially accused Morton of fudging the data he collected from measuring various skulls collected from all over the world in order to ‘prove’ that Europeans were naturally more intelligent than non-Europeans. Gould argued that Morton manipulated the data to arrive at conclusions about European intellectual superiority that the racial scientist already had in mind from the outset.

Gould had good intentions; he was keen to slap down what he perceived to be racist ideas with pernicious consequences. But the PLoS Biology paper shows how Gould was mistaken in his criticism of Morton and his work. More pertinently, the paper lays out evidence that Gould indulged in some data fudging of his own to arrive at his biased conclusions about Morton’s supposed bigotry.

Cultural critic Kenan Malik has written an incisive and in-depth article on this discomfiting case. Malik presents the PLoS authors’ arguments showing how Gould selectively picked those parts of Morton’s data that confirmed his suspicions of Morton’s racist agenda. Bear in mind that the point isn’t that Morton wasn’t biased (or incorrect) with his ideas of race; clearly he was, as were most people of his era. The point is that Gould had set out to paint Morton as a dodgy scientist who deliberately manipulated his findings to confirm an a priori assumption of European racial superiority. Yet the PLoS authors show that Gould's criticisms of Morton were often unfounded.

Another critic of Gould’s zealous anti-racist view of Morton’s work was John S Michael, who in 1988 wrote in a paper published in the journal Current Anthropology that:

Contrary to Gould’s interpretation, I conclude that Morton’s research was conducted with integrity… He was trying to understand racial variation and not, as Gould claims, trying to prove Caucasian racial or intellectual superiority.

But even Michael does not escape the analytical rigour of the PLoS authors, who wrote the following in an appendix to their paper:

While we come to largely similar conclusions as Michael, his analysis does not support his findings… Michael’s remeasurements are reported erroneously, lack specifics on individual comparisons, and are missing the key data on the population affinity of potentially mis-measured specimens… [Michael’s] defense of Morton against Gould’s claims overlooks the most relevant charges made by Gould.

Science is inescapably embedded in social and cultural contexts. Morton’s now discredited ideas about race and its connection to intelligence were largely a product of the limited knowledge and technology of his time. While Morton’s honest, if flawed, research has been vindicated by the PLoS paper, his racial ideas were eventually superseded by a more accurate conception of our species, thanks to advances in genetics and anthropology. The PLoS authors made it clear that they were defending Morton’s reputation as a meticulous scientist, not his ideas:

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. It is thus with substantial reluctance that we use various racial labels, but it is impossible to discuss Morton and Gould’s work without using the terms they employed.

As for Gould, he has been revealed to be a scientist who allowed his personal convictions – noble though they may have been – to unduly influence his assessment of a predecessor. As Kenan Malik put it:

The real importance of the expose of Gould’s dissembling is the light that it throws not on the issue of race but on the often complex relationship between science and ideology. In one sense Gould has been proved right, though not in the way he would have wanted. His distortion of Morton’s data reveals how strongly held ideological beliefs – in this case not racism but anti-racism – can persuade one to see what one wants to see among the thicket of facts.

All this criticism, counter-criticism and counter-counter criticism highlights two important points about science: Firstly, for all its vaunted claims to objectivity, science is susceptible to personal bias and subjective beliefs that affect its practice and outcomes. Secondly, despite this blind spot, science contains within itself the very antidote to its ailments of subjectivity, namely the stringent analysis, peer review and criticism carried out by scientists on other scientists. Those who engage in the scientific process act as checks on their fellow practitioners, resulting in a system that is effectively self-policing, as the PLoS authors and their paper aptly demonstrate.


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