Evolution and mirror neurons. An introduction to the nature of self-consciousness (TSC 2005)

Self-consciousness is a product of evolution. Few people today disagree with the evolutionary history of humans. But the nature of self-consciousness is still to be explained, and the story of evolution has rarely been used as a framework for studies on consciousness during the 20th century. This last point may be due to the fact that modern study of consciousness came up at a time where dominant philosophical movements were not in favor of evolutionist theories (Cunningham 1996). Research on consciousness based on Phenomenology or on Analytic Philosophy has been mostly taking the characteristics of humans as starting points. Relatively little has been done with bottom-up approaches, using performances of animals as a simpler starting point to understand the generation of consciousness through evolution. But this status may be changing, thanks to new tools coming from recent discoveries in neurology. The discovery of mirror neurons about ten years ago (Gallese et al. 1996, Rizzolatti et al. 1996) has allowed the built up of new conceptual tools for the understanding of intersubjectivity within humans and non human primates (Gallese 2001, Hurley 2005). Studies in these fields are still in progress, with discussions on the level of applicability of this natural intersubjectivity to non human primates (Decety and Chaminade 2003). We think that these subject/conspecific mental relations made possible by mirror neurons can open new paths for the understanding of the nature of self-consciousness via an evolutionist bottom-up approach. We propose here a scenario for the build up of self-consciousness through evolution by a specific analysis of two steps of evolution: first step from simple living elements to non human primates comparable to chimpanzees, and second step from these non human primates to humans. We identify these two steps as representing the evolution from basic animal awareness to body self-awareness, and from body self-awareness to self-consciousness. (we consider that today non human primates are comparable to what were pre-human primates). We position body self-awareness as corresponding to the performance of mirror self recognition as identified with chimpanzees and orangutans (Gallup). We propose to detail and understand the content of this body self-awareness through a specific evolutionist build up process using the performances of mirror neurons and group life. We address the evolutionary step from body self-awareness to self-consciousness by complementing the recently proposed approach where self-consciousness is presented as a by-product of body self-awareness amplification via a positive feedback loop resulting of anxiety limitation (Menant 2004). The scenario introduced here for the build up of self-consciousness through evolution leaves open the question about the nature of phenomenal-consciousness (Block 2002). We plan to address this question later on with the help of the scenario made available here