What is the definition of psychology?

The definition of psychology as the scientific study of behavior and mental processes is accurate because it encompasses both observable actions and internal processes that influence behavior, such as thoughts, feelings, and motivations. This dual focus highlights the comprehensive nature of psychology, which is grounded in empirical research and the scientific method.

By emphasizing the scientific aspect, the definition ensures that psychology is not merely about personal beliefs or subjective interpretations but is rooted in systematic investigation and evidence. This aligns with the core principles of psychology, as it seeks to understand how and why individuals behave in certain ways and how these behaviors are affected by a range of factors, including environment, biology, and social influences.

The other options do not capture the full scope of psychology. For example, the study of human interactions focuses more on social psychology and interpersonal dynamics, not the broader elements of behavior and mental processes. Evaluating cognitive functions is a narrower aspect of psychology that does not account for emotional, social, or environmental factors. Similarly, analyzing social structures pertains more to sociology than to the psychological processes that underlie human behavior. Thus, the chosen answer effectively encapsulates the comprehensive and scientific nature of psychology as a field of study.