Wanderlust. Restlessness. Shpilkes. In our sedentary society, Attention Deficit Hyperactivity Disorder (ADHD) means disrupted classrooms and lost worker productivity. But for nomads, it might be the key to success. A new study in the journal BMC Evolutionary Biology says that DRD4, the gene frequently associated with ADHD, behaves differently across environments, and might cause those who whither while sitting down to excel in a roaming lifestyle.