major contributions emanating from sagvolden et al.'s theory include elucidation of the role in attention-deficit/hyperactivity disorder (adhd) of temporal information processing, social learning, and response extinction learning. key issues include a need for clearer explanation of the relative role of impulsivity versus response suppression/inhibition in the dual process model, and delineation of genotype-environment correlations versus interactions in the social and experiential mechanisms posited.