Moving Beyond Nature Versus Nurture in Forensic Psychology: Toward an Integrative Biosocial Understanding of Criminal Behaviour

Abstract

The question of whether criminal behaviour arises primarily from biological inheritance or from environmental circumstances has shaped criminological and forensic psychological theory for well over a century, yet contemporary research increasingly suggests that framing the issue as a dichotomy between nature and nurture obscures more than it reveals. This paper reviews evidence from twin, adoption, and molecular genetic studies indicating that genetic factors such as variants of the monoamine oxidase A (MAOA) gene are associated with antisocial and violent behaviour primarily in interaction with adverse environmental conditions, rather than independently. It then examines the emergence of biosocial criminology and epigenetics as integrative frameworks that conceptualise genes and environment as interacting and mutually influencing systems, including gene-environment interaction, gene-environment correlation, and the molecular embedding of environmental stressors through epigenetic mechanisms. The paper further considers how individuals outside forensic psychology interpret biological evidence about offenders, noting research suggesting that lay observers do not consistently appreciate the interactive nature of gene-environment relationships when evaluating culpability. The paper concludes that forensic psychological practice, including risk assessment, expert testimony, and rehabilitation planning, is best served by frameworks that explicitly integrate biological and environmental factors rather than by frameworks organised around the question of which factor predominates.

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