intolerance of uncertainty
Intolerance of uncertainty (IU) describes the degree to which a nervous system needs predictability in order to function — not as a preference, but as a genuine operational requirement. When outcomes are unknown or plans unconfirmed, a high-IU nervous system tends to generate contingencies: running through variables, gathering information in advance, and finding it difficult to settle until enough is known. For many autistic and ADHD adults, IU runs at a higher baseline than in the general population, and shows up in everyday experiences like needing to know the plan before you can be present, finding plan changes disproportionately disruptive, or preparing carefully for situations in order to free up bandwidth to actually enjoy them. It's not about rigidity or control — it's a nervous system requesting the information it needs to work properly.



