Mental state attributions and the side-effect effect

The side-effect effect, in which an agent who does not specifically intend an outcome is seen as having brought it about intentionally, is thought to show that moral factors inappropriately bias judgments of intentionality, and to challenge standard mental state models of intentionality judgments. This study used matched vignettes to dissociate a number of moral factors and mental states. Results support the view that mental states, and not moral factors, explain the side-effect effect. However, the critical mental states appear not to be desires as proposed in standard models, but rather ‘deeper’ evaluative states including values and core evaluative attitudes.

► Three pairs of matched vignettes were used; moral valence of outcome was manipulated. ► Side-effect effect (asymmetric judgments of intentionality) was observed in all vignettes. ► Mental states, but not moral factors, mediated vignette → intentionality link. ► Moral factors did not influence mental state attributions.