Our Origins: How and Why We Do and Do Not Differ from Primates

Abstract

Questions about human origins and uniqueness are at the core of unraveling the essential building blocks of human nature. Probably no other single topic has received more attention across the sciences and humanities than the question of what makes us human and how humans differ from other primates and animals. Evolutionary anthropologists can contribute important comparative evidence to this debate because they adopt a broad perspective that considers both the ancestors of the human species as well as its closest living biological relatives. In this chapter, I review some recent insights into human nature based on this perspective. My focus is on social behavior and its underlying adaptations and mechanisms, because this is the realm of man’s most salient features. In contrast to many mainstream contributions on this topic, I emphasize shared behavioral similarities between humans and other primates and outline their underlying mechanisms. These behavioral features shared with other primates include much of our homeostatic behavior and many of our emotions and cognitive abilities, so that together they appear to represent the submerged part of an iceberg. I also briefly summarize some of the uniquely human traits forming the tip of the iceberg and outline current attempts to explain their origin. Accordingly, in this context shared intentionality represents a crucial psychological mechanism that may have been reinforced by a switch to a cooperative breeding system in early Homo evolution. In conclusion, this essay contends that the key essential building block defining human nature is like the core of a Russian doll, while all the outer layers represent our vertebrate, mammalian, and primate legacies.