When minds matter for moral judgment: intent information is neurally encoded for harmful but not impure acts

Abstract

Recent behavioral evidence indicates a key role for intent in moral judgments of harmful acts (e.g. assault) but not impure acts (e.g. incest). We tested whether the neural responses in regions for mental state reasoning, including the right temporoparietal junction (RTPJ), are greater when people evaluate harmful vs impure violations. In addition, using multivoxel pattern analysis, we investigated whether the voxel-wise pattern in these regions distinguishes intentional from accidental actions, for either kind of violation. The RTPJ was preferentially recruited in response to harmful vs impure acts. Moreover, although its response was equally high for intentional and accidental acts, the voxel-wise pattern in the RTPJ distinguished intentional from accidental acts in the harm domain but not the purity domain. Finally, we found that the degree to which the RTPJ discriminated between intentional and accidental acts predicted the impact of intent information on moral judgments but again only in the harm domain. These findings reveal intent to be a uniquely critical factor for moral evaluations of harmful vs impure acts and shed light on the neural computations for mental state reasoning.

Keywords: moral judgment; purity; temporoparietal junction; theory of mind.

Fig. 1.

Theory of mind localizer contrast of Belief > Photo, group random effects analysis, k > 10, P < 0.001, uncorrected, x = 2, y = −56, z = 24. RTPJ highlighted.

Fig. 2.

Temporal BOLD response in the RTPJ for intentional and accidental harmful and impure acts, normalized as PSC from baseline. Time window labels: B = Background, A = Action, O = Outcome, I = Intent, J = Judgment.

Fig. 3.

Whole brain contrast of (A) Harmful > Impure, y = −49, z = 16, and (B) Impure > Harmful, x = −4, z = 31. Group random effects analysis, P < 0.05, FDR uncorrected.

Fig. 4.

Conjunction (orange) between the independent contrasts of Belief > Photo (Yellow), and Harmful > Impure (Red), each viewed at a threshold of P < 0.05, FDR corrected. Viewed at x = 61, y = −52, z = 33.