The evolutionary origin of the collective unconscious and the appeal of research on Neanderthals and other ancient humans

Why does research on Neanderthals attract public attention far beyond its immediate scientific relevance? Such fascination may reflect more than intellectual curiosity; it may involve the activation of deep symbolic structures that Carl Jung termed the collective unconscious. Integrating evolutionary biology, genomics, paleoanthropology, and psychology, I address a question Jung did not explicitly pose: when, along the human evolution, did the collective unconscious originate? I argue that this structure emerged gradually rather than suddenly. Homo erectus established a cognitive floor characterized by basic schemas of fear, group cohesion, and hierarchy, without evidence of symbolic elaboration. Homo heidelbergensis, the common ancestor of Neanderthals and Homo sapiens, is proposed as the strongest candidate for the emergence of proto-archetypal cognition, given its enlarged brain, social complexity, and possible forms of mortuary behavior. The symbolic system was operational in Neanderthals and archaic H. sapiens and became fully visible with the symbolic expression of the Upper Paleolithic. I further introduce the concept of the “incorporated other” to explain the distinctive psychological salience of Neanderthals and Denisovans. Unlike other extinct organisms, these archaic humans remain present in contemporary populations through genetic introgression, collapsing boundaries between self and other, past and present. I propose that this condition contributes to public fascination in ways not fully explained by resemblance, category ambiguity, intuitive essentialism, or the uncanny. The “incorporated other” predicts that genetic incorporation itself increases perceived self-relevance and engagement, even when similarity is held constant. Neanderthals are therefore psychologically salient because they are simultaneously extinct and biologically present.