Autism & Developmental

Refining our Understanding of Anxiety in Autistic Youth: Examining the Role of Behavioral Inflexibility.

Harrop et al. (2024) · Journal of autism and developmental disorders 2024
★ The Verdict

The Behavioral Inflexibility Scale predicts anxiety in youth better than age, IQ, or diagnosis, so screen for rigidity first.

✓ Read this if BCBAs assessing or treating autistic clients under 18 in clinic or school settings.
✗ Skip if Practitioners serving only adults or clients without developmental concerns.

01Research in Context

01

What this study did

Harrop et al. (2024) asked parents to fill out the new Behavioral Inflexibility Scale (BIS). The scale captures everyday rigidity like trouble with new foods or schedule changes.

They also gave standard anxiety questionnaires to autistic and neurotypical youth. Then they checked which scores best predicted anxiety.

02

What they found

BIS scores beat age, IQ, and even autism diagnosis at forecasting anxiety levels. More rigidity meant more worry in both groups.

The link stayed strong across the whole age range studied.

03

How this fits with other research

A Boyd et al. (2024) tracked the same kids for a year and watched BIS scores move as children matured. Their data give confidence that the scale is sensitive to real change, not just a one-time snapshot.

Baker et al. (2025) looked at older autistic teens and young adults. They found emotion-regulation skills, not inflexibility, drove anxiety in that age band. The two studies together suggest the prime target shifts from rigidity in childhood to emotion skills after puberty.

Richards et al. (2017) and Spackman et al. (2025) echo the rigidity-anxiety link using youth self-report and mixed-diagnosis samples. The pattern holds no matter who answers the questions or what labels the youth carry.

04

Why it matters

Add the free BIS to your intake packet today. A high score flags anxiety risk faster than sifting through developmental history. If rigidity is high, weave flexibility drills into treatment and watch anxiety as the outcome. For teens, layer in emotion-regulation work as well. One quick measure now guides two clear intervention paths.

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→ Action — try this Monday

Print the BIS, give it to parents at intake, and prioritize flexibility programs when scores are high.

02At a glance

Intervention
not applicable
Design
pre post no control
Sample size
236
Population
autism spectrum disorder, neurotypical
Finding
positive

03Original abstract

Prior research has demonstrated that cognitive inflexibility is associated with anxiety in autistic individuals. Everyday patterns of behavioral inflexibility (e.g. observable inflexible behavior in the context of the need to change or adapt and that is manifested in real-world everyday settings) is common in autism and can be distinguished from performance on discrete cognitive tasks that tap flexible attention, learning, or decision-making. The purpose of this study was to extend this prior work on inflexibility in autism but with measures specifically developed with input from stakeholders (caregivers and clinicians) for autistic youth designed to measure everyday behavioral inflexibility (BI). We characterized anxiety in a large sample of autistic (N = 145) and non-autistic youth (N = 91), ages 3 to 17 years, using the Parent Rated Anxiety Scale for Autism Spectrum Disorder (PRAS-ASD). Further, we sought to understand how BI, measured via the Behavioral Inflexibility Scale (BIS), predicted anxiety compared to other variables known to increase anxiety in youth (chronological age, IQ, autism diagnosis, assigned sex at birth). Autistic youth had higher parent-related anxiety and BI compared to non-autistic youth. BI was the strongest predictor of anxiety scores, irrespective of diagnosis. Overall, our findings highlight the importance of BI to the understanding of anxiety in autistic youth.

Journal of autism and developmental disorders, 2024 · doi:10.1146/annurev.clinpsy.3.022806.091358