Personality development is affected by both biological and social factors,or both personal and situational variables.

Personality development is a complex process that is influenced by a range of biological, environmental, social, and personal factors. While genetics and other biological factors play a role in shaping personality, social experiences and environmental influences are also important. Personal variables, such as beliefs and values, interact with situational variables, such as life events and experiences, to shape personality development over time. Therefore, personality development is affected by both biological and social factors, or both personal and situational variables.