personality. Over the years personality psychologists have been searching for ways of mapping out personality as a whole, providing methods of measurement and a deeper insight into human behavior. The theories that have been developed help us understand and predict human behavior, whether that be within a group, society or as an individual. Trait theorist’s work on the belief that a person’s personality is defined by what kind of traits they possess. A personality trait can be defined as “â€¦ relatively stable cognitive, emotional and behavioral characteristics of people that help establish their individual identities and distinguish them from others” (Passer, et al., 2009) The study of personality traits have taken on many forms, “â€¦ the number of personality traits, and scales designed to measure them, has escalated without an end in sight.” (Goldberg 1971.) This leads the researchers and practitioners to the issue of which scale or approach to choose from. (Oliver. P. John & Sanjay Srivastava.)
Therefore for this assignment I have chosen to compare the Trait Approach with the Biological aspects of personality. There will be an evaluation of both approaches, taking a view on just how useful they are when attempting to understand personality.
In order for personality traits to be developed, psychologists focused back on language in order to find the correct basis for scientific experimentation, this meant that psychologists extracted relevant terms from the dictionary so that they would be able to classify certain traits. Researchers believed that many of the relevant terms that would be seen as valid sources for scientific taxonomy can be found in our natural language.
This ‘Lexical approach’ suggests that most of the socially relevant and salient personality characteristics have become encoded into out natural language. Therefore providing and broad yet fixed, set of attributes that people have found useful in their daily interactions. (Goldberg. 1981)
This approach led to the development of Cattell’s 16 Personality Factor Model, yet he too relied on previous work developed by various other psychologists within the same field. The development of Cattell’s work was based from research done by Allport and Odbert in 1936. In their lexical study, they developed a list of almost 18,000 terms, once this list was developed it gave personality psychologists the task of somehow minimizing and organizing the list, this tedious task was being conducted for the next 60 years. The list was later reduced through the work done by Cattell. He used both semantic and empirical clustering as well as persona-logical literature to eliminate almost 99% of the terms that Allport and Odbert developed. Through the costly and complex data-analysis that Cattell went through he concluded that he had identified 12 personality factors, amounting to 16 in his 16 Personality Factor Questionnaire (16PF). In order to develop his 16 Personality Factor Questionnaire (1965) he asked thousands of participants to rate themselves on various characteristics, and also by receiving data from those that knew the participants as well, through his findings he identified 16 behavioral clusters.
However there has been a varied amount of criticism towards the 16PF mainly due to an inability to replicate. In Howarth and Brown’s (1971) factor analysis of the 16 Personality Factor Model they concluded that 10 factors failed to relate to items present in Cattell’s own model. However despite criticism his development of the 16PF did lead the way for investigation and later the discovery of
“Eysenck’s Extraversion – Stability model” and the “BIG FIVE” dimensions of personality. These newer approaches seem to follow the idea that there should be fewer traits. Hans J. Eysenck developed the Extraversion – Stability Model favoring only two dimensions, (Extraversion – Introversion, and stability – Instability,) these dimensions are also retained in the more recent “BIG FIVE” model. Fiske (1949) and Tupes and Christal (1961) simplified the variables that were focused on in Cattell’s 16PF, these factors were known as Openness, Conscientiousness, extraversion, agreeableness and neuroticism. These five factors have been consistently focused within studies of different cultures. These traits propose that these five factors can be universal throughout the whole human species. (John and Srivastava, 1999; Trull and Geary, 1997)
Nevertheless these theories have also gone through a lot of scrutiny. It does seem a little improbable to be able to predict or even understand personality with just five or even fewer dimensions, It is possible that the more traits that are included within a model such as Cattell’s would capture greater differences in personality when various situations and stimuli are encountered. Even the “BIG FIVE” factor model agreed with this criticism and added a further six subcategories into its personality test. Yet even if more specific traits were used to predict behavior, their ability to predict in varying situations would still be limited. (Cervone, 1999)
In contrast many of these Trait theories do not take into account biological factors, such as hormonal regulation, brain structure and function, and also genetics. They simply assume that personality is based on traits collected from natural linguistics. Nonetheless, Eysenck’s (1967) trait theory was one of the first to include a biological basis for major personality traits. He understood that “Personality Theorists can only benefit from discovering what lightâ€¦other sciences may have to shed on their problemsâ€¦” and so he made an attempt at converging trait psychology with other biological scientist’s in order to dig deeper into the subject. He noted that there were many links between Introversion-Extraversion, Stability – instability and differences in a person’s pattern of arousal within the brain. He held that those that were highly introvert had high levels of arousal within the brain, and those that were linked with low levels of arousal were therefore highly extravert. The extravert therefore seeks high levels of social contact in order to achieve an optimal level of cortical arousal.
In 1999 Pickering and Gray distinguished the difference between stability and instability when linked to arousal levels. There discovery was that unstable people have a nervous system that shows a large and sudden shift in arousal, whereas those which are more stable have much more gradual and less significant shifts.
In addition, there have been various alternatives to Eysenck’s theory. One other biological explanation suggested was the Reinforcement sensitivity theory developed by Jeffrey Gray. The hypothesis was developed by taking the biological level of analysis as a starting point, in contrast to Eysenck, who developed his connection with the biological aspect after the Extraversion – Stability Model was made. Gray’s theory proposes that differences in personality originate from variations of sensitivity of inner biological systems of reward and punishment. This theory suggests that individual differences are developed at a young age as we are developing new skills and are encountered with reward or punishment while learning these new skills. In his theory he put forward two forms of “Super Traits” The Behavioral Approach System (BAS) suggesting that the person would be more sensitive to reward when learning new behaviors, and the Behavioral Inhibition System (BIS) signifying that the person would have a greater sensitivity to punishment. These two systems can be directly linked to the personality map developed by Eysenck, thus adding to the vast spectrum of personality traits.
Nonetheless the intertwining of the Trait Approach and the Biological has moved the research of personality in to more exciting and new directions, technical advances have allowed more in-depth research into twin studies. For instance Peter Borkenau et al (2006) experimented on 168 identical and 132 fraternal twins; the experiment consisted of social encounters and problem solving.
A comparison of the twins was conducted leading researchers to the conclusion that 25 percent of the variations in their behavioral patterns were attributed to genetic factors.
A further study suggested that there be a correlation between heritability and personality (Bouchard’s Minnesota Study of Twins, 1979.)The research involved a psychological assessment of Monozygotic and Dizygotic twins that have been reared apart, yet they were also assessed on their intelligence. The documentation of these figures was taken by the behavioral geneticist Matt Ridley (1999.) From the evidence provided by the twin study it would seem that there was a very high influence on genetics on intelligence, as in some cases the results were very high, and well above 80 per cent.
Even Eysenck used this evidence to suggest that the heritability of intelligence was approximately 70 per cent for the whole population. Throughout the years there have been a high number of studies that suggest a similar opinion to that of Eysenck. Twin studies in Germany and Poland have shown that there is a stronger correlation in personality with Monozygotic Twins than there is of fraternal twins, (Riemann, Angleitna & Strelau, 1997) therefore to an extent supporting Eysenck’s view.
Therefore to conclude it would not be entirely correct nor valid to state that the trait approach is superior to the biological or vice versa, as it is evident that both have increased the understanding of personality, and thus providing ways of predicting behavior within groups, societies and individuals. The theories that have been put forward have had a great impact on how we view personality and in so doing having a large effect on its uses. Nevertheless, it would also be suitable to suggest that both approaches when combined and researched have allowed for the study of personality to move forward and achieve a greater depth and understanding on personality.