Final answer:
Dr. Khan is likely a behavioral psychologist, focusing on the modification of habits through individual commitment and varying strategies tailored to individual differences.
Step-by-step explanation:
Dr. Khan, who wants to study the process of changing a habit, is most likely a psychologist specializing in the field of behavioral psychology. Changing a habit requires a commitment on the part of the individual to alter their thinking and behaviors, and can vary greatly depending on individual differences and biases. This area of study may encompass understanding the mechanisms of habit formation, identifying strategies for habit change, and evaluating the effectiveness of different approaches to habit modification.