Carl Rogers was a psychologist that believed that personality was based on the motivation and drive to be the best that we can be. We have an innate purpose to live our life to the fullest potential.
Eysenck's theory thought that every human has a biological predisposition for personality along with our childhood experiences. , He believed that people were either extraverted or introverted, along with being stable or unstable, which then created a circle model.
Costa and McCrae devised a model of 5 main traits within humans. Openness, conscientiousness, extraversion, agreeableness, and neuroticism. It stays consistent throughout life