In our research we wanted to find an answer to the question: what kind of temperament and character traits do students have who become bullies through school bullying, and what their typical emotional reactions are. In the study 410 children (post-primary education at elementary schools), 205 girls and 205 boys took part. In our research we used the following instruments: the Questionnaire on School Bullying, the Hungarian adaptation of Goch’s Family Socializational, the Hungarian adaptation of the Parental Bonding Instrument, the Hungarian version of Cloninger’s Temperament and Character Inventory, and the Hungarian version of Differentional Emotions Scale. The results of our research show that increased maternal overprotection as well as a rule or conflict oriented family atmosphere stand in the family socialization background of the students who become bullies through school bullying. The personality of bullies is characterized by a novelty seeking temperament, which is associated with an immature character. The emotions of bullies are characterized by feelings of anger and disgust, which force them to take emotion driven actions. They direct anger in an aggressive way towards their peers. The results of the research also revealed the major gender differences in the examined fields/areas.