Gray's biopsychological theory of personality

The biopsychological theory of personality is a model of the general biological processes relevant for human psychology, behavior, and personality. The model, proposed by research psychologist Jeffrey Alan Gray in 1970, is well-supported by subsequent research and has general acceptance among professionals. Gray hypothesized the existence of two brain-based systems for controlling a person's interactions with their environment: the behavioural inhibition system (BIS) and the behavioural activation system (BAS). BIS is related to sensitivity to punishment and avoidance motivation. BAS is associated with sensitivity to reward and approach motivation. There is evidence that the Behavioral Inhibition and Behavioral Activations system are connected to mood control, with positive or negative emotions occurring when rewarded or punished. Those with a relatively high BAS are said to be extroverted and outgoing while those with a high BIS tend to be more reserved and introverted. Psychological scales have been designed to measure these hypothesized systems and study individual differences in personality. Neuroticism, a widely studied personality dimension related to emotional functioning, is positively correlated with BIS scales and negatively correlated with BAS scales. The biopsychological theory of personality is similar to another one of Gray's theories, reinforcement sensitivity theory. The original version of Gray’s reinforcement sensitivity theory of personality was developed in 1976 and Gray revised it independently in 1982. Then in 2000 further and more thorough revisions were made alongside McNaughton. The purpose of the revision was to adapt the theory according to new inputs of scientific findings since the 1980s. Reinforcement sensitivity theory arose from the biopsychological theory of personality. The Biopsychological Theory of Personality was created in 1970 after Gray disagreed with Hans Eysenck's arousal theory that dealt with biological personality traits.