by Peter S. Jensen, M.D., David Mrazek, M.D. Penelope K Knapp, M.D., Laurence Steinberg, Ph.D., Dynthia Pfeffer, M.D., John Schowalter, M.D., and Theodore Shapiro, M.D., Journal of American Child & Adolescent Psychiatry, December 1997.
Summary by Teresa Gallagher:
The many authors of this article echo Thom Hartmann’s “Hunter in a Farmer’s world” concept. They look at ADHD behavior through an evolutionary lens and describe how ADHD behavior may have been life-saving in earlier hunter/gatherer societies.
“Given the current estimated frequency of ADHD (3% to 5%), it is unlikely that such a “disorder” could be as prevalent in the human species if not maintained within the species by selection forces that conveyed certain advantages to some ADHD characteristics or other associated traits.”
The three major diagnostic criteria of hyperactivity, impulsivity and attention differences were examined to see if these traits might actually have helped our ancestors to survive.
Hyperactivity: Organisms which are exploratory (on the lookout for threats and opportunities) may be more adaptive, especially in environments in which food is scarce and dangerous predators lurk. Increased motor activity and the exploratory behavior associated with ADHD may have been useful within this context. I have always identified most with the “explorer” concept, and find it interesting that the authors linked exploratory behavior with hyperactivity in animals. An exploratory temperament would quite naturally lead to increased creativity, which may explain why ADDers tend to be so inventive.
Incidentally, Bill Allsopp of Project Lab has found that kids who do best in his hands-on science & technology class have very high levels of curiosity compared with their classmates. They display exploratory behavior by readily taking apart old appliances and trying out new things when directions are lacking. “Normal” kids, the ones who do well in most classrooms, falter under this environment as they wait to be told exactly what to do. Bill found a very complete description of his best students when he read a list of ADD traits.
The authors note that animals which live in harsher or changing environments are in fact more hyperactive as they forage and search. The young of such animals are also hyperactive even though they are playing and not foraging or hunting yet. When hyperactive fox pups play in a frenetic manner they are gaining experience and sharpening their survival skills for later use. Interestingly, juvenile animals are hyperactive only when they are in the presence of a caregiver. If they are away from safety or experiencing novel stimuli the hyperactivity ceases. Anyone with an ADHD child should recognize this behavior.
Attention Processes (scanning and rapidly shifting attention): Animals which live in environments where they are preyed upon and in which food is scarce must be vigilant. Otherwise they may be caught by a predator or miss a meal. A scanning type of attention might be quite adaptive for such an environment. Moreover, when young animals (or humans) are raised in a dangerous environment, or an environment with a lot of novel stimuli, they may develop even more of a scanning attention type. Although the authors don’t elaborate, this could mean that ADHD kids raised in fast-paced modern times might become more ADHD than they otherwise would be. An endless stream of large busy classrooms, fast-paced TV shows, amusement parks, malls and tight schedules may present an environment which encourages the young plastic brain to mold itself towards a scanning form of attention.
Impulsivity: The authors define this term as “an organism’s quick response to environmental cues while not considering alternative responses to the cues.” Impulsivity was also found to have advantages.
|“The organism that does not quickly pounce on a potential prey or dodge a potential predator may not get another chance. The relative danger of false-positive responses could easily be outweighed by the ‘downsides’ of missing a critical cue in dangerous or resource-scarce environments.”|
Early Environments: Humans evolved as hunter/gatherers for a few million years, and as agricultural beings for only 10,000 years, so it makes sense that much of our behavior still reflects our hunter/gatherer heritage. The authors believe that earlier environments ranged from gentle and stable to harsh and changing. ADHD traits would have been most adaptive in harsh or changing environments such as a frozen steppe. Kinder, more stable environments may have been more amenable to other types of personalities, perhaps including “Farmers” of the future. In other words, Hartmann’s “Farmers” Diversity of personality traits would have been important. In such kinder regions individuals with ADHD traits would likely have become “successful warriors on a primitive battlefield.”
Clinical Implications: The authors believe that modern school environments are the exact opposite of what ADHD children need and that alternative schools designed for the ADHD learning style be employed. I whole-heartedly agree and have a page on alternative schools.
|“Alterations in the environment may reduce the adaptive strain on a child’s nervous system whose set-point may be at the other pole from the environment in which he or she finds himself or herself.”|
They also believe that clinicians should reframe their views of ADHD when counseling patients. A child seen as “response-ready” may be viewed in a more positive light than one labeled with a disorder.
My comments: Researchers, clinicians and parents should be open-minded to the idea of ADD being perfectly normal but different: an exploratory temperament held by our hunter/gatherer ancestors. Russell Barkley, a noted researcher in the field of ADD, recently hypothesized that ADD is caused by genetic mutations. But his idea is inconsistent with modern theories of evolution. Genetic mutations are not passed down from generation to generation on a large scale unless they provide some advantage to the population. If anything, the reverse is more likely to be true. Hunter-gatherer genes may have been the original genes, and “normal” or “Farmer” genes may have appeared later as a result of random mutations. (Barkley’s paper on ADHD appeared in Scientific American and can be viewed at http://www.scientificamerican.com/1998/0998issue/0998barkley.html.)
Resources: The full version of this paper is currently available at http://www.hypies.de/add/evolutio.html (this is on someone else’s website).
Anyone who would like to read more about ADD as an evolutionary trait can either obtain the paper at a library or read some of Thom Hartmann’s books (below). In addition, the original “Born to Explore!The Evolution of ADD and Creativity” article was also along these same lines.
Thom Hartmann books: Reader reviews at amazon.com:
Attention Deficit Disorder – A Different Perspective, by Thom Hartmann, $12.00. The original “Hunters in a Farmer’s World” book.
Beyond ADD –– Hunting For Reasons In The Past & Present, by Thom Hartmann, $10.36 Mythical Intelligence Inc., 1996. My favorite Hartmann book.
ADD Success Stories – A Guide to Fulfillment for Families with ADD, by Thom Hartmann, $17.47 Mythical Intelligence Inc, 1995.
Think Fast! The ADD Experience, Edited by Thom Hartmann & Janie Bowman with Susan Burgess, $10.36 Underwood Books, 1996.