Introduction
Biological theories of crime seek to explain criminal behavior by reference to physiological, genetic, neurological, or evolutionary factors. Unlike sociological theories that emphasize social structures or cultural norms, biological theories focus on individual traits, predispositions, and processes within the body and brain that may increase the risk of offending. Historically controversial, these perspectives have evolved from crude determinism (the idea of a “born criminal”) to sophisticated biosocial models integrating genetics, neurobiology, psychology, and environmental factors.
Biological theories do not claim that crime is caused solely by biology but explore how biological factors can influence behavior alongside social and environmental contexts. This overview traces the development of biological criminology from its 19th-century origins to contemporary research.
Theory
Historical Foundations: Lombroso and the Positivist School
The earliest systematic biological theory of crime is often credited to Cesare Lombroso, who in the late 19th century proposed that criminals were „atavistic“ throwbacks to an earlier evolutionary stage. According to Lombroso, innate physical features such as cranial asymmetries or facial anomalies marked people as born criminals. His research, presented in L’Uomo Delinquente (1876), reflected the broader Positivist School’s commitment to empirical, scientific methods, but was rightly criticized for determinism, racism, and unsystematic methodology. While Lombroso’s strict biological determinism is obsolete today, he remains a pivotal figure in the history of criminology.
Genetics and the „Born Criminal“ Debate
Modern genetics moved beyond Lombroso’s idea of visible physical stigmata to study heritability and genetic risk factors for criminal behavior. Twin and adoption studies have sought to disentangle genetic from environmental influences, often finding moderate heritability for antisocial behavior. The notion of a “crime gene,” such as the so-called “warrior gene” (low-activity MAOA-L allele), has gained attention, though results remain debated and often overinterpreted. Critics have pointed to sampling biases, measurement issues, and the dangers of genetic determinism. Additionally, research into the supposed XYY „supermale“ syndrome in the 1960s suggested a link to criminality, but later studies largely refuted the association as a statistical artifact.
Importantly, the historical counter-example of Australia challenges genetic determinism: although many early settlers were transported convicts from Britain, Australia today does not exhibit higher crime rates, undermining notions of inherited criminality (an argument used, for example, by John Braithwaite).
Neurobiology and Brain Injury
Biological criminology has also explored the relationship between brain structure, function, and behavior. One famous case is Phineas Gage, a 19th-century railroad worker who survived an iron rod passing through his frontal lobe. After the injury, Gage displayed profound personality changes, including impulsivity and poor social judgment—often cited (though debated) as evidence of the brain’s role in self-control and moral behavior. Modern neuroimaging research has advanced this line of inquiry, identifying differences in brain regions such as the prefrontal cortex and amygdala in individuals exhibiting violent or antisocial behavior. However, such findings are probabilistic and interact with social and psychological factors rather than offering simple, deterministic explanations.
Hormones and Endocrinology
Researchers have examined hormonal influences, particularly testosterone, on aggression and crime. While meta-analyses suggest a modest positive correlation between testosterone levels and aggressive behavior, the relationship is complex and mediated by context, social learning, and cultural norms. Some studies have speculated about cross-cultural variations—for instance, noting Japan’s relatively low violent crime rates alongside lower average testosterone levels in men—but such claims are contentious and risk cultural essentialism.
Psychopathy and Personality Disorders
Another strand of biological research examines psychopathy and related personality disorders. PsychopathyA personality disorder characterized by persistent antisocial behavior, lack of empathy and remorse, and egocentric and manipulative traits. is associated with affective deficits (e.g., lack of empathy, guilt) and behavioral features such as impulsivity and manipulation. Some researchers have proposed biological underpinnings, including atypical autonomic responses to fear or punishment cues, or genetic contributions to callous-unemotional traits. While psychopathy is not purely biological—it is shaped by environment and development—it highlights how dispositional traits may increase the likelihood of offending, particularly for severe, violent, or repetitive crimes.
Ted Bundy (1946–1989) is one of the most studied serial killers in criminology. He exhibited classic signs of psychopathy: superficial charm, manipulation, lack of empathy, and calculated violence. Scholars have debated the role of biological predispositions—such as personality traits with genetic components or atypical neurological processing—in understanding his crimes.
While no single “crime gene” or brain abnormality can explain Bundy’s actions, research on offenders like him has driven interest in how biological factors interact with socialization, life experiences, and choices. Bundy’s case illustrates both the potential relevance and the limits of biological theories: they can help identify risk factors but cannot predict or excuse individual criminal behavior.
Critical Appraisal & Relevance
Biological theories have generated significant controversy, particularly due to their historical misuse in justifying eugenics, racism, and social exclusion. Critics argue that biological approaches risk reductionism, ignoring social contexts, inequalities, and the complex, dynamic interplay between genes and environment. They warn against deterministic narratives that can reinforce stigma, fatalism, or discriminatory policies.
Richard Ramirez, known as the „Night Stalker,“ is often cited as an example of how biological, psychological, and social factors can interact in shaping criminal behavior. As a child, Ramirez suffered multiple head injuries that may have affected impulse control and aggression regulation. He also witnessed severe violence within his family, including the murder of his cousin’s wife, and was exposed to graphic war violence through a relative’s stories and photos.
These traumatic experiences, coupled with early drug use and social marginalization, highlight that biological vulnerabilities rarely act alone. Instead, they interact with adverse environmental and developmental conditions to increase the risk of severe criminal behavior. This case underscores why many modern criminologists advocate a biopsychosocial approach to understanding crime.
Modern biosocial criminology has sought to overcome these limitations by emphasizing that biological predispositions rarely act in isolation. Instead, contemporary research focuses on interactionist models (e.g., gene–environment interactions) that move beyond simplistic “nature versus nurture” debates. A well-known example is Terrie Moffitt’s Two-Path Theory, which distinguishes between adolescent-limited and life-course persistent offenders. The latter group exhibits early-emerging neuropsychological vulnerabilities—such as deficits in executive functioning, verbal skills, and attention—that interact with adverse social environments over time. This developmental, biopsychosocial perspective illustrates how criminology can acknowledge biological influences without falling into determinism, instead exploring the complex interplay of individual risk, resilience, and social context.
It is also important to recognize that cultural narratives often link physical appearance to moral character—a legacy evident in everything from fairy-tale villains with warts and hunchbacks to movie henchmen with scars or deformities. This tendency to „read“ deviance from the body is deeply rooted in Western culture and remains relevant today. For example, contemporary right-wing discourses may still pathologize or criminalize migrants and minorities based on perceived physical differences, echoing older bio-criminological assumptions in new forms.
Literature & Further Reading
- Lombroso, C. (2006). Criminal Man (trans. and ed. by Mary Gibson and Nicole Hahn Rafter). Duke University Press.
- Raine, A. (2013). The Anatomy of Violence: The Biological Roots of Crime. Pantheon.
- Gibson, M. (2002). Born to Crime: Cesare Lombroso and the Origins of Biological Criminology. Praeger.
- Walsh, A. & Beaver, K. M. (2009). Biosocial Criminology: New Directions in Theory and Research. Routledge.
- Beaver, K. M. (2017). Biosocial Criminology: A Primer. Routledge.
