Biological Explanations of Offending Behaviour

Biological explanations of criminal behaviour propose that offending is, at least in part, caused by innate biological factors rather than purely social or environmental influences. These explanations range from the historical theory of the atavistic form (Lombroso, 1876) to modern research on genetics, brain structure, and neurochemistry. Understanding these explanations is essential for evaluating the nature–nurture debate and the issue of biological determinism in forensic psychology.

Key Definition: Biological determinism is the view that behaviour is controlled by biological factors (genes, brain structure, hormones, neurochemistry) and that individuals therefore have limited free will over their actions.

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The Atavistic Form — Lombroso (1876)

Cesare Lombroso is regarded as the founder of criminal anthropology. In his book L'Uomo Delinquente ("Criminal Man," 1876), Lombroso proposed that criminals were evolutionary throwbacks (atavisms) — individuals who had not fully evolved and therefore retained primitive physical and psychological traits that predisposed them to crime.

Physical Stigmata

Lombroso claimed that criminals could be identified by certain physical characteristics (stigmata) that resembled those of earlier evolutionary ancestors: