Thinking Fast and Slow: Implications for the Autism Spectrum
Reasoning in people with Autism Spectrum Disorder (ASD) has been characterised as being slower and more effortful than controls. People with ASD show a more circumscribed reasoning bias, and often take longer to make decisions. These differences can be understood using Dual Process Theory, which proposes two major types of processes. Type 1 processing is rapid, effortless, parallel, and often involves non-conscious processing, while Type 2 processing is slower, more effortful, sequential, and often conscious in nature. It is assumed Type 1 processes are the default response during reasoning, unless intervened upon by Type 2 processes. The most widely used behavioural assessment of Type 1/Type 2 processing is the Cognitive Reflections Test (CRT), which involves answering reasoning problems that have a rapid, effortless Type 1 response which can either be provided or supressed by a subsequent slower effortful Type 2 response (or a wrong response provided). This simple task is well-suited to test reasoning styles in people with ASD and higher autism traits.
To present the CRT to those high and low on autism traits and those with a diagnosis of ASD using two different CRT formats: (1) a ‘fast’ condition which required participants to respond as quickly as possible within 20 seconds and designed to encourage Type 1 processing, and (2) a ‘slow’ condition which required participants to wait 20 seconds before being able to respond to the question to encourage Type 2 processing. It was expected the higher autism traits group and those diagnosed with ASD would show greater Type 2 processing compared to those lower in autism traits and controls, but that this difference in reasoning would change based on the manipulation of time.
In Study 1, participants from a typical population (62 male, 58 female) completed an assessment of autism traits and the CRT in either the fast or slow condition. Participants were assigned to either a high or low autism traits groups using a median-split of their degree of autism traits. In Study 2, 23 (16 male, 7 female) students with a diagnosis of ASD completed the CRT in either the fast or slow condition.
In Study 1, significantly less Type 1 and more Type 2 responses were provided by the higher autism traits group compared to the lower autism traits group and in the slow condition compared to the fast condition (there was no interaction). In Study 2, again, there were significantly more Type 2 responses in the slow condition and a trend (p<.1) for more Type 1 responses in the fast condition.
Taken together, the results showed that Type 2 processing is more dominant in those with higher autism traits, consistent with the idea that reasoning in ASD is characterised as dominated by Type 2 processing. The significant differences between the fast and slow conditions highlights that reasoning style can be manipulated based on context. Both findings are consistent with Dual Process Theory and may have implications for developing supportive environments where slow and effortful reasoning are problematic.