Summary Criminality and what turns a person into a criminal has been a moral, legal and psychological debate. Existing literature has been faithful with exploring different sides to the nature of criminality, either by tracking criminals’ history of personal experiences or investigating their brain functions. In a different approach, this paper administers a behavioral perspective to studying the criminal tendency of human beings by processing scales that are strictly unidimensional in order to predict a criminal's number of crimes committed and severity of such crimes. The researchers argue that approaches to criminality through personal history is fundamentally flawed because an abstract variable such as a person's past is impossible to be randomized, quantified, and measured ethically. By creating and measuring six psychological and behavioral factors (social perspective-taking (intelligence stage), attachment relationship, anger, impulsivity , depression, and lying tendency) with unidimensional scales, the researchers were able to identify current factors and interactions between factors that are able to predict a criminal's counts and severity with a reliable strength ( r = 0.819 and r = 0.993).