A survey of the prevalence of stereotypy, self-injury and aggression in children and young adults with Cri du Chat syndrome.

Collins et al. (2002) asked caregivers about 66 children and young adults with Cri du Chat syndrome. They used a survey to count how many showed stereotypy, self-injury, or aggression.

The team listed each behavior by body part and action. They also looked at whether age changed the numbers.

Eight out of ten people with Cri du Chat had stereotypy. Almost nine out of ten showed aggression. Head banging and self-biting were the most common self-injury forms.

Younger kids were more likely to hit others than older ones.

Rojahn et al. (1994) found only 11% of people with ID showed aggression. Ross et al. saw 88%. The gap looks huge, but the 1994 study counted everyone with ID across the whole state. Ross et al. focused only on Cri du Chat, a syndrome known for loud outbursts. Same behavior, different base rates.

Faso et al. (2016) followed babies with developmental delay for one year. Early stereotypy predicted later self-injury. Ross et al. gives the adult snapshot that fits the same pathway: stereotypy is common first, then SIB may follow.

van der Miesen et al. (2024) pooled 11 years of treatment studies. Caregiver-run plans at home cut SIB by the same large amount as clinic plans. Ross et al. tells us how much behavior is on the table; R et al. tell us we can shrink it, even at home.

If you support someone with Cri du Chat, expect lots of movement and hitting. Start data collection early and watch for head banging. Use the same caregiver-led ABA tactics that work for other ID groups. Early stereotypy is your red flag—treat it before it turns into injury.