He is an expert in personality traits and disorders, including psychopathy, narcissism and antagonism.

Professor Miller has authored around 300 articles and co-edited two books. These include The Handbook of Antagonism: Conceptualizations, Assessment, Consequences, and Treatment of the Low End of Agreeableness. He is also the editor of Personality Disorders: Theory, Research and Treatment and former editor of the Journal of Research in Personality.

Professor Miller has won several awards in his field and is often called upon to share his expertise. He is a regular speaker at conferences, universities and organizations in the US and abroad.