Personality: types and traits

Personality comes from the Latin persona, the mask worn by actors in Greek and Roman theatre. It means a person's unique and relatively stable ways of thinking, feeling and responding across situations.

Type approaches sort people into categories:

• Hippocrates: four types based on body fluids ('humours').
• Charak Samhita (ayurveda): three types based on vata, pitta and kapha.
• The trigunas of Indian thought: sattva (goodness, calm), rajas (activity, passion) and tamas (inertia, dullness).
• Sheldon's body types: endomorph (plump; relaxed, sociable), mesomorph (strong; energetic, courageous), ectomorph (thin; brainy, artistic, introverted).
• Carl Jung: introverts (prefer being alone, inward-looking) and extraverts (sociable, outgoing).
• Friedman and Rosenman: Type-A people are impatient, competitive and always rushing, and are prone to heart disease (hypertension, coronary disease); Type-B people are relaxed and easy-going. Later, Type-C (cooperative, unassertive, linked with cancer) and Type-D (prone to depression) were added.

Types are simple, but most people do not fit neatly into one box.

Trait approaches describe personality by traits: stable qualities that vary in degree from person to person.

• Gordon Allport: cardinal traits (one dominant trait that shapes a whole life), central traits (the few that describe a person, like 'honest' or 'friendly') and secondary traits (minor preferences).
• Raymond Cattell: 16 source traits, measured by the 16PF questionnaire.
• Hans Eysenck: broad dimensions such as introversion–extraversion and emotional stability–neuroticism.
• The Big Five (Costa and McCrae): Openness to experience, Conscientiousness, Extraversion, Agreeableness and Neuroticism. (Remember: OCEAN.)