Abstract
This study aimed to build on existing research on the implicit relational assessment procedure (IRAP), which has identified different patterns of IRAP effects associated with responses to happy and angry facial expressions. In particular, the study aimed to (1) replicate the previously observed happiness superiority effect, but with a far larger participant group than previous studies and (2) explore whether the IRAP effect would be influenced by self-reported levels of depression. One hundred twenty-two participants completed an IRAP that presented pairs of emotional human faces in a 2×2 crossover design yielding four trial-types: happy face–happy face, happy face–angry face, angry face–happy face and angry face–angry face. The results showed a clear happiness superiority effect, with the IRAP effect for trial-type 1 (happy face–happy face) larger than the IRAP effect for trial-type 4 (angry face–angry face). Self-reported depression appeared to moderate responding on the trial-type 1 alone, with low depressed individuals producing a larger D-IRAP score on the trial-type 1 relative to high depressed individuals. The findings support recent arguments that the stimulus function properties of all elements within an IRAP should be taken into account when predicting and interpreting behavioral patterns produced on the procedure. Considerations for use of the IRAP to predict behaviors in the natural environment are discussed.