C800 Psychology

The aim of the essay is to discuss with evidence how do the Eysenck and the Gray theories of 'E' and 'N' agree, and how do they differ? The essay discusses if either model is well discussed with evidence.  Eysenck and the Gray theories hypothesised that personality traits aid in understanding the differences in brain functioning in an individual. Both the theories assumed that the brain process can be characterised by the means of a simplified conceptual nervous system, which contains circuits of personality and behaviour (Zuckerman, 2014).

Eysenck's Extraversion - Stability model or E model favours only two dimensions, which are Extraversion – Introversion and the stability – Instability. This theory emphasised on biological basis of the personality traits. Eysenck's studies found many links between the Stability - instability and the Extraversion – Introversion and were associated with differences in the pattern of arousal in brain of an individual. The studies concluded that extrovert people had low level of arousal in brain and they engage in high level of social contact for achieving an optimal level of cortical arousal. On the contrary, the introvert people have high level of arousal within brain (Claridge, 2016).

The studies of Gray agreed on the differences in arousal levels linked with stability and instability. Gray highlighted that people with stable nervous system/Neuroticism-stability or “N” have less significant or a gradual shift in the arousal and vice versa in unstable people. Gray developed the Reinforcement sensitivity theory based on biological analysis at starting point. On the other hand, Eysenck's studies established the theory and later made the connections to the biological aspect on this note both the theories differ (Hundt et al., 2013).  According to Gray the different personality of human beings is due to variations of internal factors of rewards and punishments. This inner biological system has variations of sensitivity that gives rise to differences in personality. Gray’s theory emerged as alternative to the Eysenck's studies (Jappe et al., 2011).

According to Gray, an individual difference in personality arises during cultivation of new skills at a young age. It is because while learning new skills a person encounters the reward or punishment. In this behavioural approach system (BAS), a person at young age learning a new behaviour is more sensitive to rewards and in behavioural inhibition system (BIS) a person demonstrates a greater sensitivity to punishment. In this aspect it can be said that the behavioural approach and sensitivity system align or are linked with the personality map developed by Eysenck. Therefore, both theories agree on this note as per Hundt et al. (2013).

Eysenck’s model was discussed with the evidence from the genetic studies on twins which revealed that variation in the behavioural patterns by 25% in twins is due to genetic factors. In some genetic studies with monozygotic and dizygotic twins who were born and bought up at different regions, the psychological assessment revealed that the intelligence was strongly influenced by twins. Based on this evidence Eysenck concluded that “heritability of intelligence” was approximately 70% of the whole population. The views of Eysenck matched with further genetic studies. The theories of Gray originated from study on biology of personal traits, motivations and contradict Eysenck’s view on explaining personality disorder based on classical conditioning alone. This model is explained with evidence from studies conducted on people with anxiety and depression that showed high BIS sensitivity (Heym et al., 2008).

Overall both the theories differ in the use of level of physiological construct. Gray used arousal in restricted manner when compared to Eysenck’s model. Eysenck's reticulo-cortical and limbic systems may be compromised of number of pathways and structures. In his studies the ascending reticular activating system (area of brain associated with arousal)is broadly defined. On the other hand the BIS and BAS system of Gray are found as separate from the arousal despite these systems are in dynamic interaction. It emphasised mainly on the Anxiety, Impulsivity, approach motivation, and avoidance motivation unlike Eysenck’s emphasis on Neuroticism, Extraversion, and arousal (Zuckerman & Glicksohn, 2016).

Based on the above discussion it can be more convincing to agree with the Eysenck's theory as arousal used by him as mediating variable and is useful to link the personality to different response indices. On the other hand Gray's more neurologically detailed theory is silent and is applicable to predict the narrower range of behaviours and for one-grained neuropsychological description.

References:

Claridge, G. (2016). Hans Eysenck's contribution to our understanding of personality and psychological disorders: A personal view. Personality and Individual Differences, 103, 93-98.

Heym, N., Ferguson, E., & Lawrence, C. (2008). An evaluation of the relationship between Gray’s revised RST and Eysenck’s PEN: Distinguishing BIS and FFFS in Carver and White’s BIS/BAS scales. Personality and Individual Differences, 45(8), 709-715.

Hundt, N. E., Brown, L. H., Kimbrel, N. A., Walsh, M. A., Nelson-Gray, R., & Kwapil, T. R. (2013). Reinforcement sensitivity theory predicts positive and negative affect in daily life. Personality and Individual Differences, 54(3), 350-354.

Jappe, L. M., Frank, G. K., Shott, M. E., Rollin, M. D., Pryor, T., Hagman, J. O., ... & Davis, E. (2011). Heightened sensitivity to reward and punishment in anorexia nervosa. International Journal of Eating Disorders, 44(4), 317-324.

Zuckerman, M. (2014). Sensation seeking (psychology revivals): beyond the optimal level of arousal. Psychology Press.

Zuckerman, M., & Glicksohn, J. (2016). Hans Eysenck's personality model and the constructs of sensation seeking and impulsivity. Personality and Individual Differences, 103, 48-52.