"Mind Over Reality Transition": The Evolution of Human Mortality Denial

Session Date: 
Mar 3, 2017
Session Order: 
7
Speakers: 

Some aspects of human cognition and behavior appear unusual or exaggerated relative to those of other intelligent, warm-blooded, long-lived social species––including certain mammals (cetaceans, elephants and great apes) and birds (corvids and passerines). One such collection of related features is our facile ability for reality denial in the face of clear facts, a high capacity for self-deception and false beliefs, overarching optimism bias and irrational risk-taking behavior––traits that should be maladaptive when they first appear as hard-wired features in individuals of any species. Meanwhile, available data suggest that self-awareness (knowledge of one’s own personhood) and basic theory of mind (ToM, also termed mind-reading, intentionality etc.) have independently emerged several times, particularly in the same kinds of species mentioned above.  Despite a long-standing opportunity spanning tens of millions of years, only humans appear to have then evolved an extended ToM (multilevel intentionality), a trait required for optimal expression of many other unusual cognitive attributes of our species, such as advanced linguistic communication and cumulative cooperative culture. The conventional view is that extended ToM emerged gradually in human ancestors, via stepwise positive selection of multiple traits that were each beneficial. A counterintuitive alternate possibility is that establishment of extended ToM has been repeatedly obstructed in all other species with the potential to achieve it, due to a "psychological evolutionary barrier".  This barrier is claimed to arise in isolated individuals of a given species that develop the genetic ability for extended ToM.  Such individuals would then observe deaths of others whose minds they fully understood, become aware of mortality, and translate that knowledge into an understanding of personal mortality.  The conscious realization and exaggeration of an already existing intrinsic fear of death risk would have then reduced the reproductive fitness of such isolated individuals (by favoring personal survival over reproduction).  The barrier would have persisted until hominin ancestors broke through via a rare and unlikely combination of cognitive changes, in which two intrinsically maladaptive traits (Reality Denial and Extended ToM) combined in the same individuals, to allow a “Mind over Reality Transition”. Once the barrier was broken, conventional natural selection could take over, with further evolution of beneficial aspects of the initial changes. This theory also provides a unifying evolutionary explanation for other unusual features of humans, including recent emergence as the dominant species on the planet, and replacement of all other closely related evolutionary cousins, with limited interbreeding and no hybrids. While not directly falsifiable by experiment, the theory fits with numerous facts about humans and human origins, and no known fact appears to strongly militate against it. It is also consistent with most other currently viable theories on the subject including Terror Management Theory.  Importantly, it has major implications for the human condition, as well as for many serious issues, ranging all the way from personal health responsibility to global climate change.

Varki, A. Human uniqueness and the denial of death. Nature. 460:684. 2009.

Varki, A., and Brower, D. Denial: Self-Deception, False Beliefs, and the Origins of the Human Mind. Twelve Books, New York. 2013.

Varki, A.: Thought Experiment: Dating the Origin of Us. The Scientist 27:28-29, 2013. 

Varki, A.: Why are there no persisting hybrids of humans with Denisovans, Neanderthals, or anyone else? Proc Natl Acad Sci U.S.A. 113: E2354, 2016.

AttachmentSize
File 2017_03_03_07_Varki-Web.mp493.74 MB