Biological categorization within Homo sapiens and its consequences for differences in behavior – or not

Abstract

Charles Darwin mentioned in his groundbreaking book “The descent of man” from 1871 (p. 227f.) that humans living today do not belong to different species, but to different subspecies and that the term “subspecies” is best suited for this. Just as is common with different species of animals, be they mammals, birds, or butterflies, “the same terms for the same degrees of difference” should be used (and not “race”). However, any biological categorization within Homo sapiens is now considered controversial. In the case of animals and plants, the concepts species and subspecies, as well as the concrete classification of individual organisms, have also been the subject of scientific debate for decades. Basically, the problem is that the continuous (and ongoing) evolutionary process has been divided by thinking into categories – where exactly should the boundaries between them be set? However, if the same phenotypic and phylogenetic criteria are applied to humans as to animals, different subspecies can also be distinguished in humans; but, as in animals, their number and exact delimitation (especially in overlapping areas) are difficult to determine. Genetic information provides additional information; it cannot replace the classical categorization by phenotype, geography and ancestry. However, no psychological differences can be inferred from such a biological categorization. If, for example, the Siberian and Sumatran tiger are distinguished as subspecies, this does not mean that they must differ in certain behavioral characteristics. The same applies to humans. Any psychological or behavioral distinction must be measured by itself and may eventually be explained by evolutionary challenges, environmental (including political-historical and cultural) or chance factors.