Neurodiversity — past adaptations, not harmful mutations

In the past decades, we have been looking at neurodiversity mostly as “there is something wrong in the brain”. For many affected people, this explanation was even a consolation and they were (at least temporarily) relieved when they got an official diagnosis. The mutation load hypothesis has been very popular — ASD children have older fathers on average; more time for harmful mutations to arise in the father’s genome.

However, this image of neurodiversity has started to crumble. It has become clear that not a single mutation is responsible for ASD, but a huge number of genes are involved and that the respective mutations are ancient and not recent. Moreover, there are high comorbidity rates among the neurodiverse, with many shared symptoms ranging from depression and anxiety to insomnia. It looks increasingly like the neurodiverse are a big family. This is also suggested by assortative mating within the neurodiverse.

In a geneticist published a highly interesting finding: genes involved in ADHD showed patterns of recent article, selective pressure in the past. This means that these genes were adaptations to the environment. Of course, an individual with typical ADHD symptoms (confusion, forgetfulness, inattention, clumsiness, etc.) would have found it harder to survive in the past, that means and “ADHD phenotype” must have been very different from now.

I think it’s time to rethink the “something wrong in our brain” approach and start to find out what’s wrong with our environment. I have been arguing that the neurodiverse have hunter-gatherer minds who live in a “farmer world”. Thom Hartmann pioneered this approach for ADHD. I think it is time to start to research the idea for other types of neurodiversity, like ASD, OCD and giftedness. The latter isn’t thought of as a clinical condition but shares many of the same “symptoms”, including hypersensitivity, hyperfocus on a special subject and sadly also frequent suicidal ideation.

Few people would think of gifted brains as neurodevelopment gone wrong and few would start looking for faulty brain structures or genes. However, there is often a mismatch between their evolved programme and their environment, this is what makes gifted people depressed and anxious. In evolutionary theory, a mismatch occurs when past adaptations are becoming malfunctioning. A famous example is our craving for sugary and fat foods, which was adaptive in our past as it ensured we chose the highest calorie foods, but which has become maladaptive in the present, where we have food in abundance.

What might have been the adaptations in the past? If we look at common traits of neurodiverse people, some might be easy to identify:

  • high sensitivity (noise, smell, etc.) to detect danger, toxic plants, etc.
  • deep processing of the environment (plants species, insects, etc.)
  • hyperfocus (radar mind for prey and focus of all resources on the catch)
  • sensitivity to social criticism (fear of ostracism)
  • higher stress reactivity (already seen in “highly reactive” infants)
  • different chronotype (heightened vigilance)
  • different social cognition

Some of the emergent mismatch phenomena may be

It’s time to start research on “What’s wrong with the environment for hunter-gatherer minds”. We should be able to avoid a lot of undesired outcomes on hunter-gatherer minds.

Originally published at http://the-big-ger-picture.blogspot.com on May 29, 2020.