Autism attenuates the perception of the mind-body divide

Abstract

People are intuitive Dualists-they tacitly consider the mind as ethereal, distinct from the body. Here we ask whether Dualism emerges naturally from the conflicting core principles that guide reasoning about objects, on the one hand, and about the minds of agents (theory of mind, ToM), on the other. To address this question, we explore Dualist reasoning in autism spectrum disorder (ASD)-a congenital disorder known to compromise ToM. If Dualism arises from ToM, then ASD ought to attenuate Dualism and promote Physicalism. In line with this prediction, Experiment 1 shows that, compared to controls, people with ASD are more likely to view psychological traits as embodied-as likely to manifest in a replica of one's body. Experiment 2 demonstrates that, unlike controls, people with ASD do not consider thoughts as disembodied-as persistent in the afterlife (upon the body's demise). If ASD promotes the perception of the psyche as embodied, and if (per Essentialism) embodiment suggests innateness, then ASD should further promote Nativism-this bias is shown in Experiment 3. Finally, Experiment 4 demonstrates that, in neurotypical (NT) participants, difficulties with ToM correlate with Physicalism. These results are the first to show that ASD attenuates Dualist reasoning and to link Dualism to ToM. These conclusions suggest that the mind-body distinction might be natural for people to entertain.

Keywords: autism; innateness; intuitive psychology; theory of mind.

Fig. 1.

The perceived embodiment of psychological traits, as gauged by the “will transfer to the replica” responses. Bars show grand means calculated over by-subject averages. In this and all figures, asterisks mark a significant difference between the group mean and chance (indicated by the dotted line) and error bars indicate SE of the subject means.

Fig. 2.

The perceived disembodiment of psychological traits, as gauged by the “will emerge in the afterlife” responses. Bars show grand means calculated over by-subject averages.

Fig. 3.

The perceived innateness of psychological traits, as gauged by the “innate” responses. Bars show grand means calculated over by-subject averages.

Fig. 4.

The correlation between performance on the ToM task (speed and errors) and Dualism. Errors are mean proportions (across items); the RT is the mean correct response (in seconds, averaged across items). Significant correlations are indicated by bolded lines. The arrows in the margins indicate the patterns of performance predicted by each probe. Thus, for the Afterlife probe, higher choice proportions are associated with Dualism, whereas in the Replication task, they suggest Physicalism.

Fig. 5.

The hypothesized link between intuitive ToM and performance on the ToM and Dualism probes.