Varki’s theory says that if a species evolves a brain powerful enough to understand that it will die then it must simultaneously evolve the ability to deny reality or else the genes for the more powerful brain will not fix in the gene pool due to reduced reproductive fitness caused by depression.
Varki also explains why the brain’s denial mechanism is general rather than specific. This means it tends to deny all unpleasant things, not just mortality.
How else can we explain that James Hansen, the finest climate scientist in the world, understands that we must reduce CO2 emissions to avoid human extinction, yet also believes we can do so without reducing our standard of living or population?
un-Denial 