So much interesting research is going on here in Philadelphia. Here's a study that was just published yesterday suggesting some visible brain differences show up in autistic people as young as six months. I'm collecting a file on human variation and evolution, hoping to write a series of columns that take an evolutionary view of such conditions as autism, ADHD, dyslexia and shyness. Why are we humans so different from one another? Are some of these differences holdovers from earlier eras, when different types of behavior proved advantageous? When people didn't spent their childhoods forced to sit in chairs and absorb lectures? Or are some of these conditions byproducts of the sheer complexity of the human brain?
Variation drives evolution, and if our environment changed, some of the people who are labelled with various conditions and disorders might thrive better than those deemed "normal." Does human variation help explain why humans have become such a successful species?
The new study was summarized in a blog post for abcnews. One thing that struck me about this post was the statement that parents haven't done something wrong to cause autism in their children. Historians of medicine have reminded me that before the vaccine scare, there was something called the "refrigerator mother" hypothesis. Doctors blamed mothers for being too cold to their children. While the vaccine scare is a problem, the refrigerator mother idea caused pain and suffering for families as well. Here's a piece of the story from the abcnews health blogs:
The study, which tracked MRI images of 92 infants from 6 to 24 months, found that infants who went on to develop autism may have had brain abnormalities visible on MRI at 6 months of age, before the development of clinical symptoms.