Do It Again

Spend any time with a toddler and you will notice them performing stereotyped behaviors such as rocking, flapping hands and banging objects together. Parents, particularly new parents, might find these odd, but they are not usually anything to worry about. I used to see my kids (when they were babies) repeatedly bashing a rattle on the floor, for example, or flapping their hands around in a stereotyped way. There is some research to suggest that these activities serve a useful function in helping children to develop motor control¹. Restricted interests, such as insisting that one's teddy bears are arranged in a particular order, are also a common feature of early childhood.

The technical term for these behaviors is 'restricted and repetitive behaviors' (RRBs). What might alarm some parents is that RRBs are also characteristic of developmental disorders such as autism. In some cases, normal stereotypies become part of a troubling and mysterious syndrome. Clearly it's important for researchers to work out whether there are particular kinds of RRB that are a cause for alarm, and what the usual developmental picture is for the appearance and disappearance of these behaviors.

In a study that has just been published in the Journal of Developmental and Behavioral Pediatrics, we set out to investigate just how common these behaviors are in toddlerhood². The research was funded by the Economic and Social Research Council, and it involved us working with a sample of 15-month-olds who are part of a longitudinal study in the north-east of England. We asked parents to fill in a 20-item questionnaire, the Repetitive Behaviour Questionnaire-2 (RBQ-2)³, which had previously been used in a study of two-year-olds but not yet with kids as young as 15 months. The items in the questionnaire ask parents about a range of RRBs, such as whether children are ever seen to spin themselves around and around, or whether the toddler likes to look at things from particular or unusual angles. The statistical analyses showed that the questionnaire was reliable for kids of this age. Generally speaking, the 15-month-olds scored higher on this scale (that is, evidenced a higher level of RRBs) than the 2-year-olds who had been studied previously. The most common kinds of RRB were motor RRBs, involving repetitive movements. (The other categories we looked at were sensory interests, rituals and routines, and restricted interests.) 60% of parents reported that repetitive fiddling with toys and other objects was prevalent in their children, while 51% reported high levels of pacing or moving around repetitively. Restricted interests (shown in the earlier study to be the most prevalent subtype of RRBs at age 2) was not as common in the younger toddlers.We concluded from this study that stereotyped behaviors are common in this age group and are not in themselves a cause of concern. Other research⁴ shows that children at risk of ASD show more such behaviors than controls, so we would expect these scores for motor RRBs to be even higher in an at-risk sample. There is still much to learn about these curious behaviors, but we hope that this research helps to set a baseline for what would be expected in typical development, so that we can be clearer about when things are veering towards the atypical.