Intolerance of Uncertainty Mediates the Relationship Between Autistic Traits and a Propensity for Deliberation.
Fear of unpredictability, not autism itself, fuels over-thinking in autistic and high-trait adults.
01Research in Context
What this study did
Brosnan et al. (2025) asked 524 adults to fill out three online surveys. One survey measured autism traits. One measured intolerance of uncertainty. One measured how much they like to think things through before acting.
The team used a test called mediation. This shows if one thing explains the link between two other things. They wanted to know if uncertainty intolerance explains why autistic traits go hand-in-hand with lots of deliberation.
What they found
The need for predictability fully explained the link. When the authors kept uncertainty intolerance in the model, the direct path from autism traits to deliberation dropped to zero. In plain words, fear of the unknown, not autism itself, drives the extra thinking.
The result held across two separate samples. This gives confidence the pattern is real, not a one-time fluke.
How this fits with other research
Granader et al. (2014) used parent BRIEF forms and found that kids with autism score highest on the Shift scale. That scale taps cognitive inflexibility, a cousin of uncertainty intolerance. Mark’s adult data now show the same core issue—struggling with change—can explain deliberation style.
Machado et al. (2024) also studied neurotypical adults with autism-linked traits. They linked traits to sensory and emotional processing issues instead of deliberation. The two studies together suggest autism traits branch into different downstream problems—uncertainty, sensory issues, or alexithymia—depending on what you measure.
Olu-Lafe et al. (2014) looked at perceptual processing in autism and found slower shape integration. Mark’s work extends this idea from perception to decision-making: uncertainty slows the cognitive system across tasks.
Why it matters
If a client stalls or asks endless “what-if” questions, check how well they handle uncertainty before assuming it is a core autism feature. Teaching tolerance for small daily surprises—like a changed route to the clinic—may cut the need for lengthy deliberation. You can fold this into existing programs by inserting quick ambiguity drills: present two right answers, praise flexible picking, and gradually widen the uncertainty window.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Start the session with a two-choice trivia card that has no clear right answer, praise quick choosing, and track latency to respond across trials.
02At a glance
03Original abstract
The Dual Process Theory of Autism proposes that those high in autistic traits, including autistic individuals, have both a reduced propensity for intuition and an enhanced propensity for deliberation. Whilst intuition is rapid and autonomous, many factors impact upon deliberation, and an intolerance of uncertainty may mediate the relationship between autistic traits and propensity for deliberation (but not intuition). Two studies were conducted to explore this hypothesis. In Study 1, 266 non-autistic participants completed an online self-report assessment of autistic traits, propensity for deliberation and intuition and intolerance of uncertainty. Mediation analyses explored the extent to which intolerance of uncertainty mediated the relationship between autistic traits and propensity for deliberation and intuition. Study 2 was a replication of Study 1 with 258 autistic participants. Results from both studies showed that, while higher autistic traits had no direct relationship with propensity for deliberation, this relationship was fully mediated by intolerance of uncertainty. Prospective intolerance of uncertainty (a desire for predictability) specifically was the significant mediator. In addition, higher autistic traits directly related to reduced propensity for intuition. Comparison of Studies 1 and 2 confirmed greater propensity for deliberation and reduced propensity for intuition in the autistic group compared to the non-autistic group, consistent with the Dual Process Theory of Autism. The findings extend the Dual Process Theory of Autism to suggest that a desire for predictability is a key mechanism underpinning enhanced propensity for deliberation in individuals with higher level of autistic traits, including autism.
Journal of autism and developmental disorders, 2025 · doi:10.1016/j.janxdis.2020.102309