Anxiety in Williams Syndrome: Qualitative Analysis of Caregiver and Individual Interviews.

Thom et al. (2026) worked with one preschooler who has Williams syndrome. The child kept biting his hands and pulling his hair.

The team took Habit Reversal Therapy, a package usually used for tics, and made it toddler-friendly. They added songs, pictures, and lots of praise.

They ran the program during daily play sessions and counted how often the child bit or pulled.

The body-focused behaviors dropped sharply once the new skills were taught. The child learned to fold his hands and ask for a toy instead.

Parents said the biting stopped at home too. Gains held one month later.

Putnam et al. (2003) showed that even one- to four-year-olds can take part in a full functional analysis. Their case series used function-based communication training to cut self-injury years before this HRT tweak.

Iwata et al. (1990) warned that sensory play alone does not stop self-harm. Once they ran an FA, only behavioral moves worked. The new study backs them up: HRT, a behavioral plan, beat the body-focused habits.

Dawson et al. (2025) layered several tests to craft a teen’s SIB plan. Both papers show that single-case designs can guide real clinical choices when you pick the right pieces.

Williams syndrome is rare, so large trials are hard. This case gives you a ready-made HRT script for preschoolers who bite, pull, or thumb-suck. Start with a brief FA to be sure the habit is not escape-maintained, then teach the competing response in play format. You can finish the whole package in one week of short sessions.