How did Cesare Lombroso attempt to explain criminal behavior?

Cesare Lombroso, an Italian criminologist, attempted to explain criminal behavior by shifting the focus from legalistic definitions of crime to the scientific study of the individual offender.1

His primary theory posited that a specific class of "born criminals" existed who were biological throwbacks to a more primitive stage of human evolution. He argued that these individuals exhibited a higher frequency of physical and mental anomalies, which he termed "stigmata," such as unusual skull sizes and facial bone asymmetries.12

While these views were influential in Europe for a time, they are now largely discredited. It is important to note that Lombroso’s work was more nuanced than his "born criminal" theory suggests; he also contended that crime had multiple causes and that the majority of offenders were not born criminals but were instead shaped by their environment. Ultimately, modern social science has rejected his emphasis on hereditary, atavistic traits in favor of environmental and social factors. Despite the rejection of his specific biological theories, Lombroso remains significant for establishing the search for the causes of crime as a central focus of criminology.12