Final answer:
Modern-day psychologists often use a categorical approach to classify behaviors but may also use a dimensional approach. A researcher looking at job suitability factors would likely be a personality psychologist, and case studies are commonly used in theory development.
Step-by-step explanation:
Modern-day psychologists focus on identifying behaviors according to a categorical approach. This means that behaviors are often classified in clearly defined categories, which can be diagnostically useful in fields such as clinical psychology where specific disorders are identified and treated. However, it's worth mentioning that other approaches are also utilized depending on the context and the specific subfield of psychology. For instance, a dimensional approach is also common, especially in personality psychology, where traits are seen as existing on a continuum rather than in distinct categories.
In the field of personnel psychology, a researcher interested in what factors make an employee best suited for a given job would most likely identify as a personality psychologist. This subfield focuses on understanding individual differences in behavior and how these may predict job performance. Furthermore, the use of in-depth interviews to develop theories, such as by Sigmund Freud, is known as a case study. Case studies are particularly useful for getting a detailed look at an individual or group, which can then inform broader psychological theories.
Fields like epigenetics are focused on the study of genes and their expression, while social psychology zeroes in on situational factors affecting behavior, contrasting with biological or personality-based explanations. Trait theorists in personality psychology utilize models like the Five Factor Model to explain personality in terms of enduring characteristics and behaviors. Thus, psychology is a diverse field utilizing a range of approaches to understand complex human behavior and mental processes.