What is the study of creating psychological tests, such as IQ and personality tests, called?

The study of creating psychological tests, including IQ and personality assessments, is known as psychometrics. This field focuses on the theory and technique of psychological measurement, which involves not only the construction of tests but also the validation and reliability of these tests. Psychometricians analyze the characteristics of tests to ensure they accurately measure what they are intended to—such as intelligence, personality traits, skills, or other psychological attributes.

In contrast, cognitive psychology primarily investigates cognitive processes such as perception, memory, and problem-solving, but does not focus on the measurement of these processes. Developmental psychology examines how people grow and change throughout their life spans, addressing emotional, cognitive, and social development rather than creating tests. Behavioral psychology studies observable behaviors, often emphasizing how they are learned and modified but does not pertain to the standardization or creation of psychological tests. Therefore, psychometrics is distinctly the discipline that encompasses the design, analysis, and application of psychological tests.