Personality, temperament and character are three interrelated concepts that are often confused because they are all involved in the way we feel, think or behave. 

Both temperament and character are components of our personality. However, psychology establishes limits between them based on their differentiated characteristics and the factors that intervene in their development.

Temperament

Temperament refers to the natural tendency of each of us to respond in a specific way to our environment. That is, the most instinctive reactions or automatic behaviors. Temperament is mostly determined by genetics being a reflection of our inherited characteristics and our biology, therefore, it is the component of personality that appears first being visible from the early stages of childhood or even in infants.

Having one temperament or another predisposes to both the development of certain personality traits and the development of certain emotional problems. For example, a temperament that is characterized by an overactive sympathetic nervous system may make us more prone to anxiety, while a temperament that has low levels of cortical activation behind it would make us more prone to extroversion.

Due to its strong genetic component, temperament is difficult to change since to a greater or lesser extent that tendency will always be there. However, that does not mean that it determines our personality or behavior and that we cannot learn to control what we feel or do.

Throughout history temperaments have been described from different theoretical models, the most relevant classifications being Galen’s Theory of Basic Temperaments and the classification made by Cloninger in his Psychobiological Model of Personality. Despite their differences, both models share the idea that temperament is inherited, is stable throughout life and is not influenced by the social environment.

Character

Character reflects how social and cultural factors influence temperament. That is, it is born from the influence of the environment on cognitive processes, perception and emotions to which we are genetically predisposed. 

Character is not as stable as temperament and is acquired by learning through experiences and social interactions. Therefore, it does not appear in the early stages of development but goes through different stages and does not reach its full form until late adolescence. 

Because character is acquired, it is possible to modify it, for example, through social education, changes in habits, among others.

Personality

Personality is the mixture of temperament, character and behavior, therefore, it is the sum of heredity, learned habits and the way we relate to the world.  All these factors shape not only our behavioral patterns but also the way we process information from our environment and the way we feel.

Our personality changes and adapts, especially during childhood and adolescence, and then stabilizes. After this period change, although possible, is less likely. This is why personality is something that distinguishes us and shows itself to be stable over time and across different situations.

Cloninger, Robert & Cloninger, Kevin (2011). Person-centered Therapeutics. The International Journal of Person Centered Medicine. 1. 43-52. 10.5750/ijpcm.v1i1.21

Corr, P. J., & Matthews, G. (2020). The Cambridge Handbook of Personality Psychology.