Quiz 14: Eysencks Biologically Based Factor Theory
Factor analysis is a mathematical technique for reducing a large number of variables (or traits) to a few.Both Cattell and Eysenck use factor analysis to measure personality traits or factors. Factor analysts determine intercorrelations of a large variety of measures taken from many people.Some of these intercorrelations reveal scores that tend to cluster together, suggesting a factor, or unit of personality. Next, analysts determine the extent to which each individual score contributes to the various factors.Correlations of scores with factors are called factor loadings. For mathematically derived factors to have psychological meaning, the axes on which the scores are plotted are rotated into a mathematical relationship with each other.When the rotation is oblique (which Cattell advocated), many factors result; with orthogonal rotation (used by Eysenck and the Five-factor theorists), only a few factors emerge. Traits generated through factor analysis may be either unipolar or bipolar.Unipolar traits are scaled between zero and some larger amount, and bipolar traits extend from one pole to another with zero as a midpoint (i.e., extraversion and introversion). Cattell's oblique rotation resulted in 16 first-order traits, whereas Eysenck's orthogonal rotation yielded only three general traits, or superfactors.
The five-factor model is a result of an evolution of factor analysis methods that began with Allport and was continued by Cattell in the 1940s.Costa and McCrae continued their work of factor analyzing major personality inventories until they reached a core set of five personality traits. Costa and McCrae agreed with Eysenck that personality traits are bipolar and follow a bell shaped distribution.Since most people tend to score near the middle of each trait, the extremes often gain the most attention.The two strongest and most ubiquitous traits are neuroticism and extroversion.Respectively, neuroticism reflects relative levels of emotionality and extraversion refers to relative levels of social gregariousness. The third factor, Openness to experience, distinguishes people who prefer variety and diverse experiences from those who gain comfort in the familiar, the conventional, and the traditional. The Agreeableness scale distinguishes trusting, generous and good natured people from those who are more suspicious, unfriendly, and critical of other people. The fifth, and final, factor, conscientiousness, describes people who are ordered, controlled, ambitious and self-disciplined.In contrast, people who score low on this factor tend to be disorganized, negligent, lazy, and aimless, and they often lack perseverance.
Eysenck has built his personality theory on measures of types, or superfactors.The superfactors are broader than traits, with a single trait forming a cluster of several traits.Eysenck's procedure has yielded only three general bipolar types: extraversion/introversion (E), neuroticism/stability (N), and psychoticism/superego functioning (P). Extraverts are sociable, impulsive, lively, quick-witted, and optimistic.They enjoy taking risks and seek other types of excitement, including stimulating social activities.Introverts are quiet, passive, unsociable, careful, reserved, thoughtful, pessimistic, peaceful, and controlled; they have a congenitally low cortical arousal level that keeps them from exciting, dangerous activities. High N scores are overreactive, frequently complain of vague physical symptoms, and have difficulty returning to a normal state after emotional arousal.Low N scores are emotionally stable, calm, even-tempered, and controlled. People who score high on P are not necessarily suffering form a psychosis, but they do have a high predisposition to develop pathology under periods of high stress. According to Eysenck, all three types have a strong genetic component.