Reinforcement sensitivity theory

Reinforcement sensitivity theory (RST) proposes three brain-behavioral systems that underlie individual differences in sensitivity to reward, punishment, and motivation. While not originally defined as a theory of personality, the RST has been used to study and predict anxiety, impulsivity, and extraversion. The theory evolved from Gray's biopsychological theory of personality to incorporate findings from a number of areas in psychology and neuroscience, culminating in a major revision in 2000. The revised theory distinguishes between fear and anxiety and proposes functionally related subsystems. Measures of RST have not been widely adapted to reflect the revised theory due to disagreement over related versus independent subsystems. Despite this controversy, RST informed the study of anxiety disorders in clinical settings and continues to be used today to study and predict work performance. RST, a continuously evolving paradigm, is the subject of multiple areas of contemporary psychological enquiry.

Gray's biopsychological theory of personality was informed by his earlier studies with Mowrer on reward, punishment, and motivation and Hans Eysenck’s study of the biology of personality traits. Eysenck linked Extraversion to activation of the Ascending Reticular Activation System (ARAS), an area of the brain which regulates sleep and arousal transitions.

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