What makes you who you are as a person? You probably have some idea of your own personality type — are you bubbly or reserved, sensitive or thick-skinned? Psychologists who try to tease out the science of who we are define personality as individual differences in the way people tend to think, feel and behave.
There are many ways to measure personality, but psychologists have mostly given up on trying to divide humanity neatly into types. Instead, they focus on personality traits.
Via The Learning Factor