The Interpersonal Reactivity Index (IRI), developed by Davis (1980), provides an excellent multidimensional measure of empathy for the general adult population, the domain for which it was developed. Its use has subsequently expanded into other areas, for example criminal psychology. In this domain empathy is a critical variable in theoretical accounts of criminality and particularly of violence. For many researchers within the field of criminal psychology, the IRI has become the instrument of choice for the assessment of empathy. However, the psychometric properties of the scale, when used with a criminal population, have not been investigated. This paper reports the results of an investigation into the reliability and component structure of the IRI using a sample of violent offenders. The Personal Distress subscale was found not to be reliable when used in an offender population. Furthermore, when used to assess offenders, principle components analysis did not confirm the four-subscale structure of the IRI. Possible explanations for these findings are discussed in relation to offender assessment in general
