Jeffrey Gray's theory of personality

Gray's theory of personality is framed within the biological and factorial paradigms.; this means that it explains the differences between individuals from variables related to the nervous system and that it is based on the grouping of different personality traits in higher dimensions through analysis techniques statistical.

In this article we will analyze the main aspects of the Gray model. Specifically, we will focus on the two basic personality factors and the two associated physiological mechanisms described by this author: anxiety and behavioral inhibition mechanism and impulsivity and the behavioral approach.

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Jeffrey Gray's theory of personality

The British psychologist Jeffrey Alan Gray (1934-2004) presented in 1970 his factorial-biological theory on the structure and bases of interindividual differences in personality; According to the model, these are due to biological mechanisms that are relate to reactions to reinforcement, punishment or to novel stimuli and situations.

In this sense, Gray described two main biological mechanisms that determine behavioral tendencies. He called one of them the "behavioral approach mechanism" and the other the "behavioral inhibition mechanism"; these would be equivalent to the basic factors of personality, which would have a physiological basis.

Gray's theory of personality is largely based on Eysenck's PEN model, which defines three major biologically determined personality factors: neuroticism, extraversion and psychoticism. However, there are significant differences between both theories that are worth commenting on; we will dwell on them later.

Thus, Gray proposes two basic dimensions of personality: anxiety and impulsivity. The first combines the introversion and neuroticism of the Eysenck model; on the other hand, a high level of impulsivity would also imply high neuroticism, but in this case it would be associated with extraversion. Each dimension corresponds to a behavioral mechanism.

• You may be interested in: "Eysenck's Theory of Personality: the PEN model"

Anxiety and the mechanism of behavioral inhibition

According to Gray's description, anxiety is a combination of neuroticism (or emotional instability) and introversion. In Eysenck's model, extraversion is characterized by personality traits such as activity, dominance, assertiveness, sociability and sensation seeking, and introversion would be his opposite.

The behavioral inhibition mechanism, which is associated with this primary dimension of personality, is mainly involved in the avoidance of unpleasant situations and stimuli, that is, from punishment. Since it is determined by biological variables, the mechanism would be activated to a different degree in each person.

Among the main functions of the behavioral inhibition mechanism, and therefore of anxiety, we can highlight the response to punishment, the inhibition of the obtaining of reinforcers in certain circumstances (for example, in the delay of reinforcement) and the avoidance of new and potentially aversives.

Having a high level of anxiety predisposes the person to experience frequently frustration, fear, sadness and other unpleasant feelings. Therefore, this trait is associated with behavioral avoidance of stimuli that are perceived as anxiogenic by the individual.

Impulsivity and the behavioral approach mechanism

The Impulsiveness factor of the Gray model combines high levels in Eysenck's Neuroticism and Extraversion dimensions. In this case, the relevant biological system would be the behavioral approximation mechanism, which when activated would make us behave in the opposite way to the inhibition mechanism.

So in this case the obtaining of rewards prevails over the avoidance of punishments. This behavioral system favors the approach to novel stimuli and situations and is activated mainly before the possibility of obtaining a reinforcement, unlike the mechanism of behavioral inhibition, which depends on the punishment.

According to Gray, people with a high level of behavioral approximation mechanism activity (or impulsive, if you want to say that way) tend to show more frequent positive emotions such as joy. It could be related to the action of the neurotransmitter dopamine, involved in the brain reinforcement system and motivation.

Similarities and differences with Eysenck's theory

Eysenck's and Gray's theories of personality have obvious similarities; after all, the second author drew heavily on the work of the first in developing his own model. Both are categorized into two large paradigms of the study of personality: factorial and biological theories.

A key difference between Gray's and Eysenck's theory of personality is that the former gives greater importance to physiological responses to different types of stimuli, while the PEN model is primarily based on classical conditioning, in the levels of brain activation and in the functioning of neurotransmitters.

In any case, these are two complementary theories: since Gray started from Eysenck's model, his factors can be added to those described by this author. Each of them explains different aspects of personality, and the traits they describe could be explained by different but interrelated biological variables.

Bibliographic references:

• Gray, J. TO. (1970). The psychophysiological basis of introversion-extraversion. Behavior Research and Therapy, 8(3): 249-266.

• Gray, J. TO. (1981). A critique of Eysenck's theory of personality. in h. J. Eysenck (Ed.), “A model for personality”: 246–276.