Final answer:
Phyllis should investigate the biopsychosocial model of abnormality to better understand psychological disorders.
Step-by-step explanation:
Phyllis should investigate the biopsychosocial model of abnormality to better understand the onset, progression, and treatment of psychological disorders. This model takes a comprehensive and holistic approach by considering biological, psychological, and sociocultural factors that contribute to abnormal behavior. It recognizes that psychological disorders are influenced by a combination of genetic, environmental, and social factors. For example, it takes into account biological factors such as genetics and brain chemistry, psychological factors such as thoughts and emotions, and sociocultural factors such as family dynamics and societal influences. By exploring the biopsychosocial model, Phyllis will gain a broad understanding of the various factors that contribute to psychological disorders and how they can be treated.