The behavior problem pupil in the public school classroom is of continual and vexing concern to educators and to the parents of the child. Many valid environmentally oriented theories have been advanced to explain patterns of aberrant conduct but the plausibility of these postulations may obscure questions raised about the organic fitness of some children. We cannot ignore the close relationship of brain activity to overt behavior.1 The present paper is concerned with the effects of amphetamine on the so-called hyperkinetic syndrome of behavior, so ably described by Laufer and Denhoff2,3 and the very similar "organic syndrome of behavior" defined by Bradley.4 It is characterized mainly by hyperactivity, short attention span, impulsivity, explosiveness, erratic school performance, and poor social adjustment. Teachers find these children extremely trying and make them the subject of recurrent referrals to guidance personnel. Laufer and Denhoff