Scio Ergo Sum: Knowledge of the Self in a Nonhuman Primate

The pressures of developing and maintaining intricate social relationships may have led to the evolution of enhanced cognitive abilities in many social nonhuman species, particularly primates. Knowledge of the dominance ranks and social relationships of other individuals, for example, is important in evaluating one’s position in the prevailing affiliative and dominance networks within a primate society and could be acquired through direct or perceived experience. Our analysis of allogrooming supplants among wild bonnet macaques had revealed that individual females successfully evaluate social relationships among other group females and possess egotistical knowledge of their own positions, relative to those of others, in the social hierarchy. These individuals, therefore, appeared to have abstracted and mentally represented their own personal attributes as well as those of other members of the group. Bonnet macaques also seem to recognise that other individuals have beliefs that may be different from their own, manipulate another individual’s actions and beliefs in a variety of social situations, and selectively reveal or withhold information from others—capabilities displayed by certain individuals that became evident in the course of our earlier studies on tactical deception in the species. In conclusion, the ability to develop belief systems and form mental representations, generated by direct personal experience, suggests a rather early evolutionary origin for fairly sophisticated cognitive capabilities, characterised by an objectified self with limited regulatory control over more subjective levels of self-awareness, in cercopithecine primates, pre-dating those of the great apes. We, therefore, argue, in this review, that bonnet macaques might represent an intermediate stage in the evolution of self-awareness, a process which began with the subjective awareness that characterises most, if not all, higher animal species and culminates in the most sophisticated form of symbolic self-awareness, apparently the hallmark of the human species alone