APA Dictionary of Psychology

in reinforcement sensitivity theory, the physiological mechanism believed to control aversive motivation. It is theorized to be sensitive to signals of punishment and nonreward. Activity in this system suppresses behavior that may lead to negative or painful outcomes and inhibits movement toward goals. It has also been held that this system is responsible for the experience of negative feelings such as fear, anxiety, frustration, and sadness in response to these signals and that having a strong or chronically active BIS tends to result in introversion. Compare behavioral approach system. [described by British psychologist Jeffrey Alan Gray (1934–2004)]