Personality

What is measurable.

The five factors

Openness, conscientiousness, extraversion, agreeableness and neuroticism emerge repeatedly from studies across cultures and predict some life outcomes modestly.

Conscientiousness is the strongest single predictor of job performance, and still modest.
Traits are tendencies across situations, not rules about any occasion.

Popular types

Myers-Briggs and similar type systems are widely used and poorly supported: low retest reliability and forced categories where the data shows continuous variation.