The relationship between anxiety and repetitive behaviours in autism spectrum disorder.

Rojahn et al. (2012) looked at autistic children and asked a simple question: do repetitive behaviors always mean the child is anxious?

They compared kids with high anxiety and low anxiety. Then they checked which repetitive behaviors each group showed.

The team split the behaviors into two buckets: insistence on sameness and sensory-motor repetitions.

Kids who were already highly anxious showed more insistence on sameness.

Surprise came with the low-anxiety kids. Their sensory-motor repetitions, like hand-flapping, were the ones tied to worry.

So the same behavior can signal different things, depending on the child’s overall anxiety level.

Adams et al. (2019) later asked parents and heard the same story at home, school, and the store. Parents saw setting-specific anxiety signs, backing the idea that context matters.

May et al. (2015) hunted for the usual attention-to-threat bias seen in typical anxious kids. They found nothing, hinting that anxiety in ASD rides a different brain route—maybe the one that feeds repetitive movements.

Hou et al. (2025) tracked the same behaviors for up to three years and added a new twist: boys keep higher repetitive-behavior scores than girls, and the behaviors change over time. Put together, the picture is that anxiety links, sex, and growth all shape what we see.

Stop treating every repetitive behavior as a red flag for anxiety. First note the child’s baseline worry level. High-anxiety child plus rigid routines? Target coping skills. Low-anxiety child plus sensory repetitions? Still probe for hidden stress, but look at sensory needs too. This fine-tune saves you from chasing the wrong problem.