Updated: Apr 28, 2020
When Thom Hartmann's son, Justin, was first diagnosed with ADHD, the doctor told them that ADHD was a mental disorder, so Justin should give up his dream of studying science. Hartmann rejected the doctor's pessimistic advice, and like many parents (myself included), decided to learn everything he could about ADHD. While reading an article in Scientific American, Hartmann learned that the lives of our hunter-gatherer ancestors altered dramatically when farming was introduced 12,000 years ago. For over 50,000 years, our ancestors wandered the globe in search of wild game, nuts, and berries, so their quick reflexes and hyperactive muscularity were an asset. The transition to agriculture offered a more stable food source, so the nomadic lifestyle became less common, as permanent villages were established. Hartmann reasoned that ADHD behavior is a holdover from prehistoric times.
Hartmann went on the write a book, Attention Deficit Disorder: A Different Perception, which was published in 1997. Known as the "hunter versus farmer theory," Hartmann argued that ADHD traits were adaptive in prehistoric societies, which depended upon hunting wild animals for food. Hyperactivity, characterized as excessive movement, benefited hunters because it facilitated muscle development and a quick response to threats from predators. Distractability aided hunters because it allowed them to monitor their surroundings. If a threat was detected, impulsivity kicked in, facilitating a speedy response. In a time of brutal predators, survival wasn't just for the fittest, it was also for the fastest.
Since Hartmann lacked academic training and offered no evidence to support his hypothesis, scientists greeted his theory with skepticism. Respected ADHD researcher and author, Russell Barkley led the charge, writing in The ADHD Report that a mental disorder cannot be an adaptation.
Skepticism toward Hartmann's theory has changed in the last 15 years, thanks to advances by geneticists who have found that people with ADHD carry common genes related to their behavior. To learn more, see my post, Is ADHD a Mental Disorder or an Adaptation?