This case uses two subtyping papers to illustrate the benefits and steps of model-based cluster analysis. Model-based cluster analysis allows researchers to identify groups of individuals with similar presentations across multiple variables. It can capture multifaceted relationships between variables that are too complex for correlational analysis, such as the relationship between narcissism and psychopathy. Model-based cluster analysis tests how well a standardized dataset fits 54 different models (six model types and one to nine clusters); utilizing subtyping theory and a goodness-of-fit score, the best model is selected which maximizes the difference between groups and minimizes the difference between individuals within a group. Model-based cluster analysis research has supported the existence of psychopathy subtypes.