Use of force against someone. The force that is used can take different forms, such as physical, verbal, intellectual, emotional, social, economic, and spiritual. Other than testosterone, further factors that are involved in aggressive behavior include substance abuse, and less obvious ones such as chronic obstructive pulmonary disease, dementia, stroke, and urinary tract infections. At present, there is a concern as to whether exposure to violent video games has an effect on manifestations of such behavior. Then there is the bane of all high-school teachers: passive-aggressive behavior (the use of such strategies as procrastination and wilful incompetence).
See Age-crime curve, Behavior problems, Bullying, Cingulate gyrus, Conduct disorder, Fighting, Indirect aggression, Oppositional defiant disorder (ODD), Prosocial behavior, Teasing