Which theory relates personality traits to physical characteristics in the study of crime?

The theory that relates personality traits to physical characteristics in the study of crime is phrenology. Phrenology, developed in the early 19th century, posits that the shape of an individual's skull and specific areas of the brain correlate with their personality traits and potential criminal behavior. This belief was rooted in the idea that certain physical features could indicate predispositions towards particular behaviors, making it a significant early attempt to link physicality and personality in understanding criminality.

This theory contrasts with others by emphasizing a direct relationship between physical attributes and behavior rather than environmental or social factors. While atavism involves the concept of degenerative traits linked to criminality, it does not focus specifically on personality traits as phrenology does. Classical theory centers on the idea of free will and rational choice in committing crimes, rather than the influence of physical characteristics. Biomechanics typically refers to the study of the mechanical aspects of living organisms and does not pertain specifically to personality traits or criminal behavior.