A review of experimental and correlational studies suggests that the aftereffects of stress on performance are due to a wide range of unpredictable, uncontrollable stressors including noise, electric shock, and bureaucratic stress. These effects are not limited to stressful situations that involve a lack of predictability and controllability over a distracting stimulus; they can also be induced by increased task demand. Interventions that increase personal control and/or stressor predictability are effective in reducing poststressor effects. There is also evidence for poststimulation effects on social behavior which generally involve an insensitivity toward others following stressor exposure. Studies of exposure to environmental stressors in naturalistic settings report effects similar to those found in laboratory settings. Several theories (e.g., psychic cost, learned helplessness, arousal) are examined. Some receive more support than others, but it is concluded that the reliability and generality of poststimulation effects have many causes.