Estimating the Statistical Significance of Hominin Encephalization

Abstract

Encephalization, the increase in endocranial volume through the Pleistocene, is examined from a creationist perspective. By correcting for body size using a linear regression model based on extant primates, the residual can be used to estimate the significance of the encephalization of fossil taxa. Using this method, significant encephalization is seen only in Homo and two australopiths, A. africanus and A. sediba. Since Wood (2010, 2016b) classifies all of Homo and A. sediba as human, these results indicate that all humans except H. naledi and only one nonhuman (A. africanus) are significantly encephalized. Based on these results, creationist neuroscientists ought to consider the possible causes of the encephalization trend in humans.