Most human characteristics are rooted in evolutionary adaptations that have helped the human race survive for thousands of years.
The best known evolutionary theory regards the “fight or flight” response, a spontaneous reaction that prompted our ancestors to make snap decisions when confronted with an animal attack or other threat. Although the dangers of modern life are very different, our natural inclination to either run or to stay and fight continues to keep us safe in the face of extreme stress or danger.
The evolutionary purposes of severe depression are much harder to figure out, but scientists have a number of interesting theories.
Evolution and Depression
The World Health Organization (WHO) predicts that in the near future, depression will have led to more deaths than cancer, accidents, heart disease, stroke and war combined. ScientificMind.com estimates that 30 to 50 percent of all people have met the criteria for major depressive disorder at some point during their lives.
When you consider its destructive potential, it seems highly unlikely that depression has any benefit to the human race; yet, evolutionary psychologists believe that both high and low moods serve important functions.
Depression and Analytical Thought
According to one popular theory known as analytical rumination, depression can slow our thinking and reduce levels of agitation during confrontations, thus helping us to analyze and solve problems before taking action. Also known as “depressive realism”, the deliberate thought processes associated with depression may ultimately prevent costly errors and help us to survive.
According to a similar hypothesis known as “behavioral shutdown,” a person in a low mood may simply choose to withdraw instead of blindly facing life-threatening risks or accepting situations that are clearly dangerous or unrealistic.
Although this tendency to shut down when things seem out of control may seem like an unhealthy reaction to stress, psychologists think that it helps our ancient ancestors survive through difficult periods such as famine, illness or drought.
