Routines and sameness

Leo Kanner, who first described autism in 1943, named one of its features an "anxiously obsessive desire for the maintenance of sameness" and thought it reflected a deep anxiety, as Steve Silberman recounts.^c1 The diagnostic manual DSM-5 lists "insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior" as one of four criteria in its restricted and repetitive behavior domain. Its examples include extreme distress at small changes, difficulty with transitions, rigid thinking, greeting rituals, and needing the same route or the same food every day.¹

A diagnosis needs at least two of the four criteria, so not every autistic person meets this one.²

When researchers sort repetitive behaviors statistically, they keep finding at least two groups. One is repetitive sensory-motor behavior, such as repeated movements and repeated use of objects. The other is insistence on sameness: routines, rituals and resistance to change.^3,4 The split held at every age from 2 to 9 in one group of 192 children, mostly boys, and across two instruments in 1,825 children aged 4 to 18 from the Simons Simplex Collection; both studies come from the same research group.^3,4 It also appears when autistic people report on themselves, in 275 adults aged 18 to 66.⁵ In another sample of 293 adolescents and adults, both the caregiver and the self-report forms of a repetitive behavior scale fit the two groups, though the parent interview used with children did not.⁶

The two kinds behave differently. In parent and caregiver reports, higher nonverbal IQ goes with milder sensory-motor behavior, while insistence on sameness shows no link with IQ. In adults' own reports, neither was linked to IQ.^3,4,6 A meta-analysis of 53 factor-analytic studies, 41 of them in autistic samples, found that repetitive behaviors divide further, into distinct but related factors. These include repetitive motor behavior, insistence on sameness, restricted interests, unusual interests, sensory sensitivity and repetitive language. Each factor had its own pattern of links to other traits, though the authors call the findings on those links preliminary.⁷ A meta-analysis of sex differences found no difference between autistic males and females in insistence on sameness, while males showed slightly more stereotyped behavior and restricted interests. The review also described differences in how these behaviors show in males and females, which current diagnostic instruments may not capture.⁸

In 192 children first seen at age 2 and followed to 9, sensory-motor behavior stayed fairly high while insistence on sameness started low and rose, with wide differences between children.³ When the same children (193 by then) were followed to 19, both kinds generally declined over the whole span, with some rising between 2 and 9.¹⁰ The two reports describe the same children with different statistical methods, and they do not fully agree about the years from 2 to 9. In a Canadian cohort of 421 autistic children followed from about 3 to 11, insistence on sameness took three paths: low and stable for 41.7%, moderate and rising for 52.0%, and high, peaking and then leveling off or falling for 6.3%.¹¹

Among 275 autistic adults, sensory-motor behavior, but not insistence on sameness, was lower at older ages, especially from age 50.⁵ That survey compared different people at one time; it did not follow people as they aged.

Intolerance of uncertainty is the tendency to react badly to not knowing what will happen. It is studied in anxiety research generally, not only in autism. In autistic people it goes closely with anxiety. A 2020 meta-analysis of 10 studies, with 562 participants aged 4 to 24 who were mostly male, found a large correlation between the two (r = 0.62). The authors judged the strength similar to that in a meta-analysis of non-autistic young people, though they did not test the difference. In most of the studies that had a comparison group, autistic participants scored higher on both.¹² A 2024 meta-analysis of 33 papers with 8,347 autistic participants found that repetitive behaviors, intolerance of uncertainty and anxiety all went together, with the uncertainty and anxiety link stronger in younger participants. The links were similar whether or not studies included people with intellectual disability. Many of the questionnaires used had not been checked for use with autistic people.¹³

Adults show the same pattern in the fewer studies that include them. In 176 autistic adults with an average age of 42, intolerance of uncertainty and anxiety were both higher than in 116 non-autistic adults.¹⁴ In a 2026 interview study, all 20 autistic adults, when asked about it, recognized intolerance of uncertainty as part of their anxiety.¹⁵

It is not settled whether insistence on sameness is a response to anxiety, a source of it, or a separate trait. In 1,429 children aged about 6 to 18, insistence on sameness and anxiety were only weakly, though significantly, linked. Anxiety went with irritability, attention problems and aggression, and insistence on sameness did not; the authors treated the two as separate.¹⁶ In the Canadian cohort, 95% of the small group whose insistence on sameness was high and peaking had anxiety above the clinical threshold by middle childhood, but for 36% of all the children the two followed different paths.¹¹ Later analyses of the same children found that, in a statistical model, rises in insistence on sameness came before rises in anxiety one to two years later, that each child's general tendencies toward the two were strongly linked, and that the link weakened with age.¹⁷ In 71 adolescents and young adults aged 14 to 24, the two correlated moderately, and both went with lower self-regulation.¹⁸

Several studies have tested whether intolerance of uncertainty sits between these traits. In children and adolescents, and in autistic adults, statistical models placed it between autism or sensory differences on one side and anxiety or insistence on sameness on the other.^19,20,14 In one of these, caregiver reports on 53 children aged 8 to 16, sensory differences were linked to repetitive motor behavior as well as to insistence on sameness, with intolerance of uncertainty and anxiety mediating the links; the authors suggest the two kinds may arise in different ways.²⁰ Two of the three studies share authors with the team that later developed CUES, the program described below.^19,20 In 86 autistic and 100 non-autistic adults, a model with intolerance of uncertainty and emotion regulation as the closest statistical predictors of anxiety fit the autistic group, but only when each group was analyzed separately and after the authors added paths suggested by the data. Sensory differences seemed to play a role more specific to autism.²¹ All of these studies measured everything at one time. The authors of the 2024 meta-analysis warn that interventions aimed at repetitive behaviors could take away "important coping strategies" if the causes are misread.¹³

Most research on sameness has asked parents about children. A systematic review of 35 studies in which autistic adults reported on their own repetitive behaviors found insistence on sameness and repetitive movement comparatively neglected. Most of its studies concerned sensory experiences, followed by special interests. Across the review, the behaviors helped people regulate their emotions and attention, but awareness of stigma pushed people to hide them, which was itself stressful. Samples were mostly white adults of average or higher IQ.²²

In a UK study co-written with 12 autistic adults, participants described rituals and routines that were often hidden and included repeated thoughts and mental checks as well as actions. Some had a superstitious quality, a way to make things feel "OK". What marked them as autistic was reliability, necessity and devotion. Rituals could help or harm, and participants read their "rigidity" against surroundings built for non-autistic people; on balance, they valued their rituals over suppressing them.²³ Twelve autistic adults without intellectual disability, interviewed by another UK team, described their repetitive behaviors as self-regulation, and holding them in as stressful.²⁴ In a small UK study in which 10 young people aged 13 to 20 were interviewed, they described their own repetitive behaviors with insight and gave a range of reasons for them.²⁵ In the 2026 interview study, adults named struggling with changes to routine among the autism-related experiences that could make them more anxious.¹⁵

The COVID-19 lockdowns removed routines for almost everyone at once. In a survey of 1,044 adults with and without autism in Belgium, the Netherlands and the UK, autistic adults reported a larger rise in anxiety and depression and more stress about losing their routines. They felt more relieved from social stress than non-autistic respondents and noticed less sensory and social overload, though in written answers some said they missed social contact.²⁶ In open-text answers from 79 UK autistic adults, adopting new routines was one theme. Many worried about leaving lockdown, with its new rules, in-person contact and busy places, while several valued less commuting and more control over their sensory surroundings.²⁷ Parents of 53 autistic children described uncertain situations, school among them, as a source of anxiety that affected the whole family.²⁸

Change within a day is a related but separate difficulty. In interviews, 24 autistic adults described daily "difficulties moving from one state to another", which the community calls autistic inertia. They also described its other side, the pleasure of being completely absorbed in a task.²⁹

If intolerance of uncertainty feeds anxiety, it could be a target for support. Coping with Uncertainty in Everyday Situations (CUES) is an eight-session group program for parents, developed in Newcastle, UK, and first tried with 11 parents.³⁰ In a feasibility trial, parents of 50 autistic children, all with at least one anxiety disorder, were randomly assigned to CUES or to enhanced usual care. Of the children whose parents were offered CUES, 72% had parents who attended 4 to 8 sessions, and parents and therapists found it acceptable; the trial was designed to test whether a full trial was possible, not whether the program works.³¹ An adult version was tried one to one with four autistic adults, who valued it.³²

A trial in Perth, Australia, assigned 64 children aged 4 to 7 to a version for young children, CUES-Junior, or to a waitlist; five families withdrew after assignment, before baseline measures. Right after the program, an assessor who did not know which group the children were in rated more of the CUES-Junior children as clearly improved in how they responded to uncertainty.³³ Parents also rated their children's intolerance of uncertainty lower, but they knew which group they were in. Gains at the two-month follow-up were measured against the start, not against the waitlist, which the authors note as a limit. The trial was small, and the size of the effect is very uncertain: the confidence interval for the main result ran from about 1.7 to 690.³³ CUES was developed by Jacqui Rodgers and Mark Freeston, who declare this in the feasibility trial. In the Perth trial, Rodgers helped design the study, supervised the therapists and helped interpret the results, but did not collect outcome data or run the analyses.^31,33

A different program, Unstuck and On Target, is an executive function program that targets insistence on sameness and flexibility at school and at home. In a trial in which schools rather than children were randomly assigned, 47 children in grades 3 to 5 received it and 20 a social skills program; their average IQ was 108. Both groups improved, but the program group improved more in problem solving, flexibility and planning, and in classroom observations of making transitions.³⁴ Observers did not know which program children had, but parents and teachers did, and the trial used no anxiety measure or dedicated insistence-on-sameness scale, though the authors read the flexibility gains as bearing on insistence on sameness.³⁴

Autistic writers describe routines as something that saves effort and steadies a day. Sarah Nannery writes that set routines are "so comforting and often essential for people with autism" because they control expectations. Her brain does not absorb new patterns automatically, she explains, so "my routines become my safe, known automatic pathways", times when she can stop thinking through every variable.^c3 Megan Anna Neff suggests rewatching favorite films or rereading favorite books when overwhelmed, because knowing how a story goes brings "a calming certainty", and advises listing them in advance, since burnout can make favorites hard to recall.^c4 Daniel M. Jones describes watching Star Wars every morning and night as a child, a routine that helped him face school.^c5 Orion Kelly writes that routines are not there "to look quirky or weird": "Routines are actually crucial to our mental health."^c8 Harry, a writer in his seventies in an anthology of autistic adults edited by Alex Ratcliffe, says, "Routines allow me to feel in control; they help me."^c9

Writers also explain why sameness matters. In a clinicians' guide by Donna Henderson, Sarah Wayland and Jamell White, autistic contributors give their reasons. Peter B. eats the same lunch almost every day to save limited executive function for things that matter more, and Alix L. says, "I don't freak out when my routine changes because I'm too rigid; I freak out because now I'm going into something without being able to prepare."^c10 Luke Beardon argues that many autistic people draw their stability from what they can control or what stays the same, and routines are often both, so a broken routine removes a main source of stability. Beardon's example is a person who throws a breakfast bowl across the room when the usual red-rimmed bowl is replaced by a blue-rimmed one, a reaction Beardon calls "perfectly understandable" for someone who relies that heavily on the routine's details.^c11

Several writers say the old stereotype that autistic people hate change holds some truth. Devon Price writes: "Change takes us more time to adjust to than it does for others, and we rely upon certainty and predictability as anchors when life does not make sense."^c6 Bianca Toeps says the rigid, schedule-bound TV character is not entirely wrong about many autistic people, but finds that her own anxiety comes mainly when she risks losing control; when she can decide when to eat, rest and go to bed, she will set off on a five-day trip with no plan.^c2 Nannery names her slowness to adapt and her rigidity "in moments of stress or change or emotional tension" as a weakness she works on.^c3 Sol Smith recalls the daily school routine, bus transfer included, as exhausting rather than familiar.^c7 Pete Wharmby writes that if he misses part of his morning ritual he feels "intensely uncomfortable for hours after", and that the need for routine "is stronger than most non-autistic people realise, and the penalty for deviation can be severe."^c12

Writers also describe ways to meet change. Nannery, writing as a parent, uses timers to warn her son that a transition is coming and keeps backup plans ready for when a routine cannot happen.^c3 Price recommends trying new things that are mildly uncomfortable, in a "challenge zone", so that repeated, tolerable exposures build confidence in handling the unexpected.^c6