Schizophrenia—Evolution of Humanness
Is schizophrenia bound to human evolution? Schizophrenia is a neuro-developmental disorder characterised by delusions, hallucinations, and bizarre behaviours. No other animal displays these symptoms. Depression, addiction, anxiety are all found in other animal species, but not schizophrenia. Schizophrenia is not even found in chimpanzees our most recent evolutionary ancestors. It is inheritable, and highly disadvantageous to survival of the affected person. Given this, schizophrenia should be almost non-existent. Yet it continues to affect a massive 1% of the global population. Something is pushing for the persistence of this disorder and its spontaneous manifestation in humans. Human evolution separated from the chimpanzees 5.5 million years ago when we walked upright and then acquired language abilities. Language ability developed after 'lateralisation', the separation of brain functions into the left (sequential) and right (parallel processing) hemispheres. The pecu...