Identifying Pedophilic Interest in Sex Offenders Against Children With the Indirect Choice Reaction Time Task

Pedophilia – a disorder of sexual preference with primary sexual interest in prepubescent children – is forensically relevant yet difficult to detect using self-report methods. The present study evaluated the criterion validity of the Choice Reaction Time (CRT) task to differentiate between a sample of child sex offenders with a presumably high rate of pedophilic individuals and three control groups (other sex offenders, non-sex offenders, and community controls, all male; N = 233). The CRT task required locating a dot superimposed on images depicting men, women, girls, or boys and scrambled pictures as quickly as possible. We used two picture sets, the Not Real People (NRP) set and the Virtual People Set (VPS). We predicted sexually relevant pictures to elicit longer reaction times in interaction with the participant group. Both CRTs showed main effects of stimulus explicitness and preferred stimulus gender. The CRT-NRP also yielded an interaction effect of participant group and stimulus maturity while the CRT-VPS showed a tendency in this direction. The overall effect size was moderate. Results offer support for the usefulness of the CRT task in forensic assessment of child sex offenders.