In a report published Monday in the journal Nature Human Behavior, researchers at Northwestern University in Illinois identify four personality types: reserved, role models, average and self-centered. The new approach was nothing like the basis for widely used personality tests such as the Myers-Briggs, which spits out a personality type with acronyms like INTJ, for introversion-intuition-thinking-judgment, or ESFP (that’s extrovert-sensing-feeling-perceiving).