Abstract :Incidental affect is not an epiphenomenon. In addition to the integral affect, the incidental one influences decision-making and social behavior. Although the empirical body on emotions and prosocial behavior is extensive, very few studies have focused on the relationship between incidental affect and prosocial behavior, and no study has concentrated on preschool children. Thus, this study aims to fill this gap in the literature. The main objective was to answer to the question of whether preschool children’s declared tendency to help is different depending on (i) the positive or negative incidental affect as well neutral state, and (ii) various levels of helping cost. A within-subjects experimental design was conducted. Thirty participants aged between 4 and 6 (M SD, 15 males) were involved in three experimental conditions: positive incidental affect, negative incidental affect, and neutral affective state. Prosocial behavior, operationalized as the declared intention to offer help, was measured through vignettes representing various scenarios with a social target needing help. The helping cost was low, medium, or high and was depicted in six vignettes for each category. The participants had to decide whether they would provide help to the social targets who needed help. The research hypotheses were confirmed and proved that positive and negative incidental affect are differently related to prosocial behavior. The results revealed (i) higher rates of prosocial behavior in the positive incidental affect condition than in the negative one or a neutral affective state, apart from the helping cost, (ii) nonsignificant differences in prosocial behavior in the neutral affective state and positive incidental affect when the helping cost was high, and (iii) nonsignificant differences in the neutral affective state and negative incidental affect when the helping cost was moderate. The theoretical contribution of the current study is the empirical support for the fact that prosociality is also shaped by incidental affect and helping cost. Our findings extend prior research that focused only on the relationship between integral affect and prosociality. Future research directions and practical implications were discussed. Keywords : incidental affect, preschool children, prosocial behavior, helping cost
