Final answer:
An individual's personality and situational variables determine their behavior. Social-personality psychology considers both internal and situational factors, and a personality psychologist would study traits that contribute to job suitability.
Step-by-step explanation:
An individual's personality, as well as situational variables, will determine that person's behavior. In social psychology, behavior is seen as a product of both the situation, such as cultural influences, social roles, and the presence of bystanders, and of the person, including personality characteristics. Modern approaches to social psychology recognize the complex interaction between internal and situational factors that affect human behavior, leading to the emergence of social-personality psychology as a field.
The fundamental attribution error is a concept where people tend to overemphasize internal factors as explanations for the behavior of others while underestimating the influence of situational variables. Therefore, it is more accurate to consider both situational and dispositional influences when explaining behavior.
A researcher interested in what makes an employee best suited for a given job, in terms of personality traits and patterns, would likely identify as a personality psychologist. Since personality is composed of long-standing traits that make individuals unique and drives them to consistently think, feel, and behave in specific ways, it is central to the study of behavioral outcomes.