©2019 BY MARKUS KNEER

Reading Guilty Minds

A systematic inquiry into biases afflicting mens rea ascriptions

Swiss National Science Foundation Ambizione Research Project

Theory of mind is the capacity to ascribe mental states – knowledge, beliefs, intentions – to others and ourselves. This capacity is essential for our ability to explain, predict and evaluate behaviour. Just as for moral judgment, theory of mind is of key importance for the assessment of legal responsibility. An individual is legally responsible for a crime if she (i) causally brought about a harmful outcome (actus reus) and (ii) acted with a ‘guilty mind’ (mens rea). Four mens reas are particularly prominent in most systems of criminal law – intentionality, knowledge, recklessness and negligence – and they engender different degrees of culpability. In few other contexts are mental state ascriptions of similar consequence as in criminal jurisprudence. 

The project aims to systematically investigate sources of pervasive bias in the ascription of legally inculpating states of mind, and to devises strategies that help alleviate such biases. It is divided into four parts. Part I establishes the project’s foundations: It elucidates (a) the notions of criminal responsibility and mens rea from the perspective of philosophy and legal theory, and explores (b) the legal status quo in the criminal law of Switzerland, France, Germany, the UK and the US. Parts II and III, which are dedicated to empirical work, jointly constitute the centrepiece of the project. Part II investigates experimentally whether the attribution of mental states relevant for criminal jurisprudence is afflicted by pervasive biases. Part III assesses empirically what types of measures help alleviate biases in mens rea ascriptions. The experiments will work with different sample populations – laypeople and legal experts – since the targeted countries have different systems and procedures. Whereas in Switzerland, for instance, criminal trials are decided by professional judges, Anglophone countries such as the UK and the US have a juror system. Part IV will evaluate the findings and advance concrete recommendations of how criminal jurisprudence could be improved so as to guarantee the presumption of innocence, as well as fair and equal trial conditions for all. 

The project breaks new ground in several respects: Though there is a considerable number of empirical studies concerning all-things considered judgments invoking variables such as blame and culpability, little work has been done on the attribution of mens rea, a core componentof blame and culpability. What is more, the experiments will target both laypeople andlegal professionals, whose capacity of mens reaascription has to date received next to no attention. Finally, the three comparative dimensions of the project – lay jury system v. professional judge system; the different legal codes of Switzerland, France, Germany, the UK and the US; uninitiated subjects v. legal experts – will provide comprehensive insight from which precise, system-specific lessons can be drawn.