Final answer:
Dr. Colton, self-identified with the largest subfield of psychology, is most likely a Clinical psychologist, the area of psychology primarily focused on diagnosing and treating psychological disorders.
Step-by-step explanation:
If Dr. Colton identifies himself with the largest subfield of psychology, he is most likely a Clinical psychologist. Clinical psychology is the area of psychology that focuses on the diagnosis and treatment of psychological disorders and other problematic patterns of behavior. This subfield is described as the largest area of psychology and receives significant attention in popular media. Many people mistakenly assume that all psychology is clinical psychology due to its prominence. As a clinical psychologist, Dr. Colton would be involved in both the assessment and treatment of mental health issues, as well as potentially engaging in research within this field.