A person who chooses to eat meat in a vegetarian community is behaving abnormally. Abnormal behavior goes against or is opposite to the behavior of the average individual. This definition is problematic, as it does not account for scenarios where pathological behaviors are in the majority. An alternate definition is behavior that is socio-culturally deviant, such as public nudity or swearing in front of children.
Other definitions give importance to the experience of the individual in comparison to his peers. Behaviors that result from a reaction to distress when others feel none are considered abnormal. These are called deviations from ideal mental health, and they include panic attacks and phobias. Behaviors that impede or directly threaten functioning are also considered abnormal and are referred to as maladaptive behaviors, such as eating disorders. Opposing sides argue that some behaviors threaten survival and functioning for a greater good, as in the case of a firefighter risking his life to save others. By definition, a firefighter's behavior is abnormal.
Because of these exceptions, a multi-criteria approach is frequently used to gauge a behavior's abnormality. Depressed behavior, for example, can be statistically abnormal, a violation of societal norms, deviate from ideal mental health standards and impede functioning.