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Friday, August 5, 2011

Evolutionary advantages of autism

You very rarely hear anything good about autism.  Yet, in recent years it has become more and more clear that autism is largely, if not entirely, a series of genetic disorders.  Considering that autism can sometimes be debilitating, why is the condition so common?  Could there have been an evolutionary advantage for autistic individuals?  Jared Reser of the University of Southern California thinks there was.

According to Reser, back in the hunter/gatherer days of our species, individuals with autistic traits could have had an advantage during times of scarcity.  Normally, early humans would have lived in small groups and cooperated with each other to procure food.  However, during food shortages, the tribes might have disbanded.  In those situations, autistic individuals could have had an advantage.  While they are less adept at social interactions, they excel at solitary activities like systematically searching for food.  Even if the nomadic tribes did not fracture, the troop may have valued the foraging skills an autistic person would bring to the table.

Reser is quick to point out that the most severe types of autism, what we might refer to as ‘low-functioning’, would not have fared well in any time periods or conditions.  It is the moderate to high functioning individuals who would have been able to successfully forage for food during times of famine.  That group survived to pass their genes on through the generations.  Unfortunately, random assortment of genes sometimes leads to the most severe autistic symptoms.