Final answer:
Sigmund Freud was largely responsible for emphasizing the role of science in psychopathology, with his psychoanalytic theory influencing psychology's focus on inner experiences and the unconscious mind.
Step-by-step explanation:
The individual largely responsible for the increased role of science in psychopathology is Sigmund Freud. Freud's psychoanalytic theory pivoted psychology towards considering inner experience and unconscious processes as key factors in understanding human behavior. His ideas also gained popularity during the 1920s, contributing to changing societal norms and fostering new approaches to therapy. Although Freud's methods were not always empirically robust, his insistence on developing a science of the mind was fundamental to the evolution of psychological science as we know it today.