A circumplex model of emotion was used to examine the role of hedonic tone and degree of arousal in the effects of induced mood on children's persistence behavior. A total of 45 preschool children were asked to describe and think about either exciting, calm, or sad experiences and then perform a persistence task. Heart rate was continuously recorded throughout the session. Observers' ratings of facial expressions and parents' ratings of the experiences provided convergent validation of the induction procedure. Children in the excited induction were rated as displaying facial expressions and generating situations that were high on both pleasure and arousal. The facial expressions and situations of those in the calm induction were also rated as positive, but less arousing, whereas those in the sad induction were rated as low on both. Concurrent heart rate recordings showed differential effects of the mood condition on autonomic arousal during the period when the children were generating the affect-inducing situations. These effects dissipated shortly after the beginning of the concentration phase of the induction procedure. Subsequent performance on a persistence task indicated that higher levels of arousal increased the amount of work completed, whereas higher levels of pleasure did not. Differential levels of autonomic arousal were displayed during the persistence task. These findings validate two important elements of the experimental design: excited versus calm states induce similar levels of pleasure but different levels of arousal, and calm versus sad states induce similar levels of arousal but different levels of pleasure. In previous research, hedonic tone and degree of arousal have often been confounded.(ABSTRACT TRUNCATED AT 250 WORDS) Language: en