The main aim of this study was to examine whether an assessment of implicit bullying attitudes could add to the prediction of bullying behavior after controlling for explicit bullying attitudes. Primary school children (112 boys and 125 girls, M age=11 years, 5 months) completed two newly developed measures of implicit bullying attitudes (a general Implicit Association Test on bullying and a movie-primed specific IAT on bullying), an explicit bullying attitude measure, and self reported, peer reported, and teacher rated bullying behavior. While explicit bullying attitudes predicted bullying behavior, implicit attitudes did not. However, a significant interaction between implicit and explicit bullying attitudes indicated that in children with relatively positive explicit attitudes, implicit bullying attitudes were important predictors of bullying behavior. Theoretical and practical implications are discussed.Keywords Explicit bullying attitudes . Implicit bullying attitudes . Interaction explicit and implicit bullying attitudes . Bullying School bullying is a large societal problem and is already evident among primary school children. Studies on this population show that 3-27% of the children bully, and 9-32% are bullied once a week or more (Berger 2007). Bullying has also been shown to have large negative consequences for the well-being of victims and bullies (Berger 2007;Scholte et al. 2007), which stresses the importance of targeting bullying behavior together with the factors that are related to bullying.Various factors have been found to contribute to the extent to which children bully other children. Research evidence indicates that social factors such as group membership and peer pressure, as well as individual, personal factors such as physical strength, aggressiveness, and empathy influence bullying (Rigby 2004). Another often studied individual factor is children's attitudes towards bullying. Attitudes are predictors of all kinds of spontaneous and deliberate social and non-social behavior (e.g., Glasman and Albarracin 2006) including bullying behavior (Salmivalli and Voeten 2004). Attitudes can be defined as general and enduring, concrete or abstract evaluations of a person, group, or issue and can be based on beliefs, emotions and behavior (cf. Petty and Cacioppo 1986).In attitude research, a distinction is made between implicit attitudes and explicit attitudes. Implicit attitudes are impulsive, spontaneous, uncontrolled emotional reactions and evaluations. In contrast, explicit attitudes refer to deliberate, reflective, controlled, consciously self-reported evaluations (Gawronski and Bodenhausen 2006). Dualprocess models assume that there are two different modes of information processing that underlie implicit and explicit attitudes. According to these models more automatic, impulsive, associative processes underlie implicit attitudes and more controlled, reflective processes underlie explicit During the research project on implicit and explicit bullying attitudes all authors were working at ...