“…The altered effect of reinforcement contingencies on the behavior of children with ADHD compared to normal children has been demonstrated in several studies. While reinforcing every correct response greatly improves (e.g., McInerney & Kerns, 2003) or normalizes the performance of children with ADHD (e.g., Freibergs & Douglas, 1969, referred in Douglas, 1985; Douglas & Parry, 1994; Konrad, Gauggel, Manz, & Scholl, 2000; Parry & Douglas, 1983; Worland, North‐Jones, & Stern, 1973), partial reinforcement abnormally affects the behavior of children with ADHD (Freibergs & Douglas 1969 and Parry 1973, referred in Douglas, 1985; Parry & Douglas, 1983). In several choice‐delay tasks, children with ADHD tended to choose a small reinforcer obtained at once rather than a larger reinforcer obtained after a delay (Rapport, Tucker, DuPaul, Merlo, & Stoner, 1986; Schweitzer & Sulzer‐Azaroff, 1995; Sonuga‐Barke, Taylor, Sembi, & Smith, 1992).…”