Step 1: Understanding the Concept:
This question addresses the fundamental issue of how to define abnormality in psychology. The two main perspectives are the categorical model and the dimensional (or continuum) model.
Step 2: Detailed Explanation:
(A) Quality and (B) Kind: These options suggest a categorical view, where normal and abnormal are two distinct categories of behavior, different in their fundamental nature or kind. This view is largely considered outdated.
(C) Degree: This option represents the dimensional or continuum model, which is the prevailing view in modern psychology. This model suggests that there is no sharp dividing line between normal and abnormal. Instead, mental health and illness exist on a continuum. Abnormal behaviors are seen as exaggerations or deficits of normal psychological phenomena. For example, feeling sad is normal, but chronic, debilitating sadness that meets diagnostic criteria is depression; they differ in degree (intensity, duration, impairment), not in kind.
Step 3: Final Answer:
According to the modern continuum model of psychopathology, normal and abnormal behavior differ in degree, not in kind.