Final answer:
Clinical psychology deals with treating psychological disorders, while cognitive psychology focuses on studying human thinking. Personality or industrial-organizational psychologists examine factors that affect job suitability, and human factors psychology relates to ergonomics and job satisfaction.
Step-by-step explanation:
Clinical psychology is the scientific study of optimal human functioning. This branch of psychology focuses on the diagnosis and treatment of psychological disorders and other problematic patterns of behavior.
A researcher interested in what factors make an employee best suited for a given job would likely be a personality psychologist or an industrial-organizational psychologist, the latter being part of a field that applies psychological theories and principles to organizations.
Cognitive psychology is the branch of psychology that focuses on human thinking, investigating how people understand, think about, and remember information. Finally, human factors psychology studies the interaction between humans, tools, and work systems, which includes assessing job satisfaction within the area of organizational psychology.