The study found numerous links between the level and quality of coherence and aggressiveness, which were modified by gender, primarily psychological gender, i.e., the sense of being comfortable in one’s gender-related self-concept, emotional world, and social interactions. The 193 girls and boys, who resided in reformatories in 3 Polish cities, were characterized by a similar level of coherence that was lower than average for the general youth population. The variable that differentiated the level and quality of coherence was apparently psychological gender. The girls were characterized by a higher level of general aggressiveness than boys as well as verbal aggression, anger, and hostility. Both boys and girls had similarly high scores for physical aggression. The study concludes that a strong level of coherence is usually linked with a lower tendency to experience negative arousal, aggressive attitudes, and aggressive behaviors; however, even a strong sense of coherence does not preclude experiencing negative emotions as a reaction to threatening situations, as is indicated by verbal aggression linked to higher levels of coherence. This could mean, on the other hand, that higher levels of coherence lead to more acceptable forms of aggression when threatened. Coherence was measured with the Sense of Coherence Scale (A. Antonovsky); aggression was measured with the Aggression Questionnaire (Buss and Perry); and psychological gender was measured with the Inventory of Psychological Gender (A. Kuczynska). 8 tables, 6 figures, and 41 references