Final answer:
The Social learning theory, especially as proposed by theorists like Albert Bandura, looks at both external and internal factors influencing a person, employing the concept of reciprocal determinism and observational learning to explain personality development.
Step-by-step explanation:
The theory most likely to look at the external and internal factors impacting a person is the Social learning theory. Behavioral theorists, such as Albert Bandura, acknowledge that the environment shapes behavior; however, they also believe people can influence their environment. This concept is known as reciprocal determinism. Bandura emphasized that people learn behaviors through the observation of others, which plays a part in personality development. The social learning perspective on personality is scientific and measurable.
In contrast, the psychoanalytical approach by Freud, which was later expanded by neo-Freudians like Jung and Erikson, focused primarily on internal psychological processes and was criticized for its lack of scientific rigor. Feminist perspectives would emphasize the social conditions and power dynamics that affect women specifically. The Behavioral theory by B.F. Skinner would look solely at the external environment's impact without considering internal thoughts and beliefs.