Our personality encompasses all that we are. All our little quirks, characteristics, behaviours, and thoughts which make each one of us unique. Personality plays a huge part in individual differences research and over the years many different theories have emerged.
One of the sectors of these theories are trait theories. These are also known as psychometric theories due to their measurements of personality traits through psychometric tests. Trait theories argue that every individual has certain unique traits resulting from our genes which predispose us to act a certain way in a variety of situations. These are thought to be consistent across situations and time. There are lots of trait theories of personality but here are a few of the most influential:
Eysenck conducted factor analyses on personality questionnaires and found three dimensions of personality:
- Extraversion (extraversion/introversion)
- Neuroticism (stable/unstable)
- Psychoticism (added in 1966)
According to Eysenck, extraverts are sociable and impulsive; introverts are reserved and serious; neurotics are anxious and worrying; and stables are emotionally calm and unworried. Those which fall under psychoticism tend to be lacking in empathy and more aggressive.
He also related a person’s personality to the functioning of the Autonomic Nervous System, in that someone’s personality is dependent upon the balance between excitatory and inhibitory processes within the nervous system (explained in more detail as a biological model in further posts).
The measures of these personality dimensions have been developed through many different psychometric tests, but the most recent is the Revised Eysenck Personality Questionnaire (EPQ-IR).