Cesare Lombroso was a 19th-century Italian doctor and criminologist, widely recognized as the “father of modern criminology.” At a time when crime was mostly discussed in moral or legal terms, Lombroso introduced a bold new idea: instead of asking simply “What law was broken?”, he asked “Who is the person who broke it — and why?”

Lombroso’s ambition was to bring scientific observation to the study of criminal behavior. He believed crime could be explained biologically, not just socially or morally.

The Trait Theory

Lombroso’s Trait Theory (sometimes called the “atavism” theory) argues that some individuals are born predisposed to commit crimes. According to him, these people are evolutionary “throwbacks” — biologically less evolved than others.

He believed that certain physical and psychological traits — visible in their body or face — could predict criminal behavior. These traits, which he called stigmata, included features like asymmetrical faces,

  • large jaws and cheekbones
  • long arms
  • Low forehead
  • unusual skull shape
  • other anomalies

When a person displayed several such traits, Lombroso argued, that person could be identified as a “born criminal.”

Development of Trait Theory

1. Observation and Measurement

Lombroso examined large samples of criminals. He measured their skulls, faces, limbs, and other body parts. Then he compared these measurements with what he considered “normal” individuals (soldiers, non-criminal men, etc.).

2. Autopsies and Anatomical Study

One of his most famous discoveries was while he performed an autopsy on a notorious criminal — he found a peculiar hollow at the base of the skull (the “median occipital fossa”). Lombroso saw this as physical evidence that the criminal was biologically different, more primitive, even similar to lower animals.

3. Classification of Criminal Types

Lombroso went beyond the “born criminal.” He created categories for other kinds of offenders, such as “occasional criminals,” “criminaloids,” “insane criminals,” “habitual criminals,” and “criminals by passion.”

  1. Occasional criminals / Criminaloids: People who offend because of situational triggers (e.g. temptation, social influence), not because of strong biological defects.
  2. Habitual criminals: People who gradually become criminals due to environment, repeated wrongdoing, or social influence.
  3. Criminals by passion: Those who commit crimes under intense emotion — jealousy, anger, revenge — rather than from a “born criminal” predisposition.

Lombroso believed that these different categories helped explain why not every criminal looked like his “born criminal” model.

Traits link with Signs of Criminality

According to Lombroso, a “born criminal” often had a combination of physical and psychological traits. Some of these claimed traits were:

  1. Physical / Anatomical Traits: Large or protruding jaws, high cheekbones, receding or low forehead, asymmetrical face or skull, heavy brow ridges, unusual skull shape, long arms, irregular teeth, sometimes tattoos or “primitive” markings.
  2. Behavioral / Sensory Traits: Reduced sensitivity to pain, impulsivity, restlessness, aggressive or violent tendencies.
  3. Psychological / Moral Traits: Lack of empathy or moral sense, cruelty, impulse for violence, disregard for societal norms, and sometimes a primitive mindset — as if closer to “primitive humans” than modern individuals.

Lombroso’s claim was that when multiple such traits appeared together, they indicated a person predisposed to crime — a “born criminal.”

Impact and Importance

Even though today Lombroso’s trait theory is considered outdated, his work was significant for a few reasons:

He shifted the study of crime away from purely moral or legal philosophy toward observation, data, and scientific study of criminals — thus helping build what became known as the Positive School of Criminology.

For the first time, criminals were studied as humans with biology and psychology — not just as immoral people. This opened the door to thinking about criminal behavior in a more complex light: biology, mind, environment — not just morality. 

Limitations

Modern research strongly rejects Lombroso’s claims. Some main criticisms are:

  1. His idea that physical traits can predict criminality is scientifically flawed, with no reliable evidence. What he considered signs of atavism are common variations in human appearance.
  2. He used biased samples (prisoners) and lacked control groups (ordinary non-criminals). That means his “data” doesn’t reliably show differences between criminals and non-criminals.
  3. The theory ignores social, economic, psychological, and environmental factors that modern criminology shows are very important in criminal behavior — for example poverty, childhood, peer influence, mental health, and opportunities.
  4. It applies a rigid, one-dimensional view of people — treating criminals as a separate “type” rather than recognizing the complexity and variety of human behaviour.

Because of these reasons, most criminologists now consider Lombroso’s biological determinism pseudoscience.


References

  1. Cesare Lombroso. (2019). Lombroso Theory of Crime, Criminal Man and Atavism. SimplyPsychology. Retrieved from https://www.simplypsychology.org/lombroso-theory-of-crime-criminal-man-and-atavism.html
  2. Trait theories of crime. In Encyclopedia of Crime and Punishment. Sage. (n.d.).
  3. Born Criminal Theory by Cesare Lombroso: Definition, Impact, and Criticism. (2025). CrimPsy.