Social and non-social reasoning in relation to autism and autistic traits

Abstract

Four experiments examined reasoning and decision-making tendencies across social and non-social domains in relation to autism and autistic traits in adults. Experiments were created to measure forced-choice judgments and written justifications in a comparison paradigm of social and non-social scenario-based domains. Three experiments used a scenario-based task to measure moral reasoning, while one experiment focused specifically on causal reasoning with a task following a common cause network structure. Dual Process Theories propose a distinction between two types of information processing: intuition and deliberation. Intuition represents a quicker and more automatic process, while deliberation represents a slower and more effortful process. Following this notion, the Dual Process Theory of Autism suggests a tendency of greater deliberation and less intuition in decision-making and reasoning among autistic people and those with high autistic traits. To test this hypothesis across domains to see whether these tendencies are domain-specific or domain-general, three experiments (Experiment 1, 2, and 4) recruited participants from the general population and measured their levels of autistic traits. One experiment (Experiment 3) recruited autistic and well-matched non-autistic participants for a between group comparison. Experiment 1 found a relationship between higher autistic traits and a greater reliance on deliberation for forced-choice moral judgments within the social domain, and not the non-social domain. However, Experiment 2, using a modified version of the same task, did not reveal such a relationship, which was supported with participants’ written justifications. Experiment 3 used the first version of the same task and found no meaningful differences between autistic and matched non-autistic people in their moral judgments. Experiment 3 revealed subjective yet not objective differences between groups in their reasoning and decision-making, suggesting a subjective preference for and performance in reduced intuition among autistic people. Finally, Experiment 4 revealed no substantial differences in levels of autistic traits between participants, clustered as decisive and indecisive reasoners, based on their reasoning tendencies. Consistently, across all experiments, a distinction between social and non-social domains in terms of reasoning and decision-making was found. Taken together, this thesis suggests that there is strong evidence for a distinction between social and non-social domains in reasoning and decision-making. However, this thesis does not provide strong evidence for a greater deliberation and less intuition associated with a diagnosis of autism or high autistic traits. Nevertheless, mismatch between subjective and objective reasoning and decision-making among autistic people might suggest meta-cognitive differences to non-autistic people, rather than a difference in reasoning and decision-making