Assessing personality

Personality assessment aims to understand and predict a person's behaviour with the minimum error. There are three main kinds of method.

1. Self-report measures (Allport's idea: ask people directly about themselves):

• MMPI (Minnesota Multiphasic Personality Inventory, by Hathaway and McKinley): the revised MMPI-2 has 567 statements in 10 subscales, used to identify psychological problems. The Indian version is the Jodhpur Multiphasic Personality Inventory (JMPI).
• EPQ (Eysenck Personality Questionnaire) and 16PF (Cattell).

Problems: social desirability (giving answers that look good) and acquiescence (tending to agree with everything).

2. Projective techniques (indirect methods): the person responds to unclear material, and is thought to project hidden feelings into the answers.

• Rorschach Inkblot Test: 10 inkblots; 'what do you see?'
• Thematic Apperception Test (TAT), by Morgan and Murray: the person tells a story about each picture.
• Rosenzweig's Picture-Frustration (P-F) Study: how people respond to frustrating situations.
• Sentence completion ('My father...') and Draw-a-Person tests.

They need trained experts, and scoring is slow and subjective.

3. Behavioural analysis:

• interviews and observation;
• rating scales, which can suffer from the halo effect (being swayed by one good or bad trait to rate everything high or low), the middle-category bias (rating everyone average), and extreme response bias;
• nomination (peers name who has a trait);
• situational tests (watching behaviour in a set-up situation).

Each method shows a different side of personality. Testing needs skill and training: untrained people should not use these tests to judge their friends.