6.4 The “Disordered” Mind
Depression was among the first mental “disorders” to be studied with the potential for mismatch in mind. In 2014, a team from the Max Planck Institute of Psychiatry led by Sara Santarelli, published a paper providing evidence for mismatch in psychiatric disorders. They focused particularly on major depression in mice models and found that depressive and anxious behavior, as well as reduced sociability, were much more common in mice raised in mismatched and aversive environments when compared to controls.
Because we are a highly social species, it may be that depression evolved as a mechanism to spur us into action, seeking social support when we were struggling. This would have been easy to do in the EEA, since we traveled, foraged, and lived in small hunter-gatherer bands. Our social networks were always nearby. This is greatly mismatched to the urban, computer driven environments in which we now find ourselves. Human technological advances are amazing, but they may also be at the reason depression is evolutionarily mismatched to our modern world.
In his book, Good Reasons for Bad Feelings, evolutionary psychiatrist Randolph Nesse expands on this idea as the foundational explanation for “disordered” minds in humans. From major depression to anxiety, eating disorders and grief, Nesse provides evidence for the evolutionary value of a pantheon on human mental health conditions.
Rather than trying to understand why evolution left us with diseases and disorders, Nesse turns the question on its head – how were these diseases and disorders beneficial to us in the past? This moves us from a perspective of maladaptation to one of adaptations that were so beneficial to us in the past, that they could not evolve as quickly as our environment changed.
Scientists have begun to use mismatch to understand social wellbeing and group health. In a commentary written by Roy Baumeister and Davina Robson, a lack of social belonging in school is suggested to reflect evolutionary mismatch. Because humans evolved to live in social groups ripe with peer-to-peer learning, the authors argue the need for social behavior and proper use of technology to enhance belongingness to reduce childhood loneliness and depression.
Nesse’s book and the title of this chapter section use quotation marks around disordered. This is on purpose. The term disorder suggests something is not working correctly; that it is somehow broken or not functioning. But evolutionary mismatch tells us this is not the case. Rather, our evolved emotional reactions are no longer in the environment for which they are adapted. Luckily for us, and the myriad of other species who are no longer in their EEA, emotions are the product of learning and development, too. This means we can learn to respond in alignment with new and changing social norms.
