As a genetic epidemiologist with ADHD, I find this article rather misleading. Foremost, the authors appear to equate association with causation. Demonstrating causation requires a lot more work than demonstrating an associaiton between genetic variant X and disease Y (or disease correlate). No such work was done here. Secondly, did the authors actually measure ADHD in the tribesmen? More likely they evaluated numerous biologic traits that could be correlates of ADHD and choose to highlight those that were statistically compatible with their hypothesis. Ultimately, I am concerned what research like this communicates about complex chronic diseases to those outside our small community - a sort of deterministic notion that completely negates the roles of other environmental factors and/or other genetic variants.