they couldn't measure all the skulls, they do not know whether the average cranial capacities that Morton reported represent his sample accurately. The journal stated that Gould's opposition to racism may have biased his interpretation of Morton's data, but also noted that "Lewis and his colleagues have their own motivations. Several in the group have an association with the University of Pennsylvania, to whom Morton donated his collection of skulls, and have an interest in seeing the valuable but understudied skull collection freed from the stigma of bias and did not accept Gould's theory "that the scientific method is inevitably tainted by bias." In 2014, the group's paper was critically reviewed in the journal Evolution & Development by University of Pennsylvania philosopher professor Michael Weisberg, who tended to support Gould's original accusations, concluding that "there is prima facie evidence of a racial bias in Morton's measurements". Weisberg concludes that although Gould did make several errors and overstated his case in a number of places, Morton's work "remains a cautionary example of racial bias in the science of human differences". In 2015, biologists and philosophers Jonathan Kaplan, Massimo Pigliucci, and Joshua Banta published an article arguing that no meaningful conclusions could be drawn from Morton's data. They agreed with Gould, and disagreed with the 2011 study, insofar as Morton's study was seriously flawed, but they agreed with the 2011 study insofar as Gould's analysis was in many ways not better than Morton's. University of Pennsylvania anthropology doctoral student Paul Wolff Mitchell published an analysis of Morton's original, unpublished data, which neither Gould nor subsequent commentators had directly addressed. Mitchell concluded that Gould's specific argument about Morton's unconscious bias in measurement is not supported, but that it was true, as Gould had claimed, that Morton's racial biases influenced how he reported and interpreted his measurements, arguing that Morton's interpretation of his data was arbitrary and tendentious: Morton investigated averages and ignored variations in skull size so large that there was significant overlap. A contemporary of Morton, Friedrich Tiedemann, had collected almost identical skull data and drawn conclusions opposite to Morton's on the basis of this overlap, arguing strongly against any conception of a racial hierarchy.Mitchell, P.W. and Michael, J.S. (2019). "Bias, Brains, and Skulls Tracing the Legacy of Scientific Racism in the Nineteenth-Century Works of Samuel George Morton and Friedrich Tiedemann" In Jackson, Christina, and Thomas, Jamie (eds.). Embodied Difference: Divergent Bodies