The Subtle Landscape

  Awesome!  The Economist is such a great magazine!  I just learned from reading the current issue (June 14 – 20 ) why my attention span is so short.  Ahem.  Among other things.

  It’s about attention-deficit hyperactivity disorder.  Those with ADHD are impulsive.  They “have trouble concentrating on any task…they flit from activity to activity… tend to perform poorly in society [and] are prone to addictive and compulsive behavior”.  C’est moi!  Yo comprendo!

  Turns out I owe my restlessness to nomadic ancestors.

  Testing has shown that ADHD is a genetic condition. “It is associated with particular variants of receptor molecules for neurotransmitters in the brain”.  Variant 7R of protein DRD4 has been shown to be associated with “novelty seeking, food and drug craving, and ADHD”.

  The neurotransmitter here is dopamine which, as you may know, is associated with reward and pleasure.  The thought is that people with ADHD are getting hits of dopamine (aka positive feedback) for behavior that seems inappropriate in today’s society.

  How could this have come to be?  Well, we’ve not long been desk jockeys and the sorts of things associated with ADHD might have well served our nomad and hunter-gatherer ancestors.  Couch potatoes would not have fared well, would they?

  Recent research in Kenya supports this hypothesis.  The Ariaal people are historically nomadic.  Those now among them with the variant receptor and who continue to wander were found to be “better nourished” than those without.  By interesting contrast, those members of the group that had the variant but had settled down were worse than those without.

  A further question is why, if important, the variant is found only amongst 20% of the population.  Could be that the “effects are beneficial only when they are not universal”. 

  I buy that.  Somebody’s got to poke sticks at snakes and do the peyote ceremonies etc while the rest keep the fire burning. And the latter would tolerate the presence of the former for only the briefest of intervals – eg long enough to drop off the day’s catch.

  I’ve always felt like the odd one out.  Now I understand.  Everybody else is missing a gear. 

(For some reason, this reminds me of something that Patagonia founder Yvon Chouinard said in an interview that appears in the June/July issue of Businessweek Small Biz:  “My favorite quote about entrepreneurship is that to understand an entrepreneur, you should study a juvenile delinquent”.)

This entry was posted on June 20, 2008 at 2:47 pm and is filed under consciousness/psychology, Evolution, Family. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.