The Dual Process Theory of Autism, Systemizing and Formal Logical Reasoning.

Background:

Autism Spectrum Disorder (ASD) has been characterised by a drive or bias towards deliberative, systematic processing relative to intuitive, social-emotional processing – the opposing bias typically being seen in the general population. Two cognitive theories provide a framework for considering relatively preserved or enhanced logical reasoning in people with ASD and people from the general population with high levels of autistic-like traits. Hyper-systemizing accounts, propose these groups are high in systemizing, which is characterized by a drive towards understanding and predicting rule-based systems. The Dual Process Theory of Autism on the other hand, proposes that autistic people and people high in autistic-like traits bias towards deliberative processing, which is characterised as slow, effortful, sequential, conscious processing that is heavily dependent on working memory and related to individual differences in general cognitive ability. This is contrasted with a bias away from intuitive processing which is characterised as autonomous processing which is typically rapid, effortless, parallel, and non-conscious, that is independent of working memory and cognitive ability. Sex differences have been reported inconsistently in these capabilities.

Objectives:

To identify sex differences in, and correlates of, self-reported systemizing, deliberation and intuition with a behavioural assessment of logical thinking in a general population sample.

Methods:

104 participants (52 male, 52 female, ages 18-66, mean 22, sd 6) from the general population completed an online assessment comprising the Systemizing Quotient-short (SQ) to measure self-reported drive to systemize and the Rational Experiential Inventory to measure self-reported deliberative and intuitive reasoning ability and engagement. The Test of Logical Thinking (TOLT) was then undertaken to behaviourally measure formal reasoning ability.

Results:

There were significant sex differences, with males scoring higher, in SQ (t=4.88, p<.001), deliberative ability (t=2.02, p<.05) and deliberative engagement (t=2.34, p<.05). There were no significant sex differences in intuitive reasoning ability and engagement or on the TOLT. A partial correlation (controlling for sex) identified that TOLT significantly correlated with deliberative ability (r=.26, P<.01) and deliberative engagement (r=.25, p<.05) but not the SQ nor intuitive ability or engagement. The SQ significantly correlated with deliberative ability (r=.36, p<.001) and deliberative engagement (r=.45, p<.001) but not intuitive ability or engagement. There were no significant correlates of age.

Conclusions:

In a general population sample, those who self-report a higher levels of deliberative ability and engagement also perform better on a test of logic and formal reasoning ability. This is consistent with the Dual Process Theory of Autism. Self-reported systemizing did not correlate with the test of logic and formal reasoning ability. The SQ has been characterised as assessing systemizing drive, which is higher in autism, as is deliberation. Consistent with this, the strongest correlation was between SQ and deliberative engagement. Sex differences were identified in self-reported deliberative ability and engagement, but were not reflected in actual performance. It may be, therefore, that self-assessments of such capabilities are vulnerable to response biases in the general population. The Dual Process Theory of Autism proposes autism is also associated with reduced intuition, suggesting this bias would not be evident in autism.