Figure 1.
Cladogram of the hypothesized patterns of personality evolution in the parvorder Catarrhini. Personality structures are described as a combination of “basic” or “blended” dimensions, e.g., Friendliness in rhesus macaques is a blend of Altruism and Sociability. The evolutionary transitions are interpreted as the integration or disintegration of these dimensions, shown by horizontal arrows between groups of dimensions. The possible transition points, indicated by the dashed lines, are placed according to phylogenetic parsimony. This picture is likely to change as more species are assessed. The structure of the genus Pan is represented by chimpanzees and the family Cercopithecidae by rhesus macaques. Figure by the authors, licensed under a Creative Commons Attribution Unported License and published under the terms of this license.