Latin aggression-, aggressio attack, from aggredi to attack, from ad- + gradi to step, go


  • 1 : a forceful action or procedure (as an unprovoked attack) especially when intended to dominate or master
  • 2 : the practice of making attacks or encroachments; especially : unprovoked violation by one country of the territorial integrity of another
  • 3 : hostile, injurious, or destructive behavior or outlook especially when caused by frustration


Agression, in psychology, as well as other social and behavioral sciences, refers to behavior between members of the same species that is intended to cause pain or harm. Predatory or defensive behavior between members of different species is not normally considered "aggression." Aggression takes a variety of forms among humans and can be physical, mental, or verbal. Aggression should not be confused with assertiveness, although the terms are often used interchangeably among laypeople, e.g. an aggressive salesperson.

There are two broad categories of aggression. These include hostile, affective, or retaliatory aggression and instrumental, predatory, or goal-oriented aggression. Empirical research indicates that there is a critical difference between the two, both psychologically and physiologically. Some research indicates that people with tendencies toward affective aggression have lower levels of intelligence than those with tendencies toward predatory aggression.

Across many different human cultures, men are more likely than women to express aggression by means of direct physical violence. Women are more likely to instead express aggression through a variety of indirect or nonphysical means.[1]