According to the journal of "Aggressive Behaviour", an analysis across 9 countries found boys reported more in the use of physical aggression. At the same time no consistent sex differences emerged within relational aggression. It has been found that girls are more likely than boys to use reactive aggression and then retract, but boys are more likely to increase rather than to retract their aggression after their first reaction. Studies show girls' aggressive tactics included gossip, ostracism, breaking confidences, and criticism of a victim's clothing, appearance, or personality, whereas boys engage in aggression that involves a direct physical and/or verbal assault. This could be due to the fact that girls' frontal lobes develop earlier than boys, allowing them to self-restrain.