How the Denial of Death Defines the Human Species
Discussion
Un-denial:
"This is my short version of Ajit Varki and Danny Brower‘s Mind Over Reality Transition (MORT) theory. A longer more complete version by the authors is here, here, and here, and an excellent video version is here. I also wrote a broader narrative here.
The human brain is much more powerful than the brain of any other species.
Why?
Most people ask “what’s special about humans?”.
It’s the wrong question.
A powerful brain with an extended theory of mind is clearly a useful adaptation for an intelligent social species because it has permitted humans to take over the planet.
Evolution frequently re-discovers successful solutions. For example, the eye independently evolved in several different species.
The correct question is “what’s prevented other intelligent social species like chimpanzees, elephants, crows, and dolphins from evolving brains similar to humans?”.
The answer is that a more powerful brain with an extended theory of mind becomes aware of mortality by observing common dangerous activities like hunting and childbirth, and this awareness of death causes depression and reduced risk taking, thus preventing the trait from being passed on to the next generation.
This barrier has prevented the evolution of a more powerful brain in all but one species.
Crossing the barrier requires an improbable evolutionary event, analogous to the energy per gene barrier that blocked complex life for 2 billion years until a rare endosymbiosis (merging) of prokaryotes (simple cells) created the eukaryotic cell (complex cell common to all multicellular life).
About 100,000 years ago, one small group of hominids in Africa broke through the barrier by simultaneously evolving an extended theory of mind with denial of death.
While denial of death may appear to be a suspiciously complicated behavior to evolve quickly, it can, for example, be implemented by a modest tweak to the fear suppression module that mammals use when forced to fight. A side effect of this solution is that not only is death denied, but anything unpleasant is denied, thus the adaptation manifests as denial of reality (aka optimism bias).
On its own, denial of reality is maladaptive because it causes behaviors not optimal for survival. However the two maladaptive behaviors, an extended theory of mind and denial of reality, when combined, become highly adaptive by enabling the evolution of a more powerful brain, which is clearly useful for an intelligent social species.
The probability of an extended theory of mind plus denial of reality emerging at the same time is very low, and apparently has occurred only once on this planet, just as the eukaryotic cell emerged only once.
In a geologic blink, that small lucky group outcompeted all other hominids and every other species on the planet."