Diminished Capacity, Neuroscience, and Just Punishment

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In the United States, ‘diminished capacity’ is a generic term that is usually not technical and is often confusing. It applies to a number of claims based on mental abnormality that a criminal defendant can raise at trial to avoid or to diminish liability for the crime charged. It is also raised at sentencing to reduce a convicted defendant's sentence. To understand diminished capacity in US law, including the relevance of neuroscience and privacy concerns, it is first necessary to understand the structure of criminal liability, which is quite similar to English law. This chapter begins with an overview of US law. It then turns to a legal and moral analysis of the specific claims that are encompassed by the term ‘diminished capacity’. With this background in place, the chapter next considers the relevance of neuroscience to these claims and whether raising and adjudicating them involves serious concerns about privacy. It concludes that neuroscience has little relevance today to most diminished capacity claims and that privacy is not a major problem. In the future, however, neuroscience may be more relevant depending upon what it discovers about the relation between the brain and the criteria for criminal responsibility.


US law, neuroscience, privacy, criminal liability

Publication Title

I Know What You're Thinking: Brain Imaging and Mental Privacy

Publication Citation

In I Know What You're Thinking: Brain Imaging and Mental Privacy (Sarah Richmond, Geraint Rees & Sara J.L. Edwards eds., Oxford 2012)

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