Prevalence and types of aggressive behaviour among adults with intellectual disabilities.

Eberhart et al. (2006) mailed a short carer checklist to services across England. They asked about any aggressive act the adult with ID had shown in the past year.

The team counted everything from loud swearing to serious injury. The final tally came from 3,165 adults.

Just over half of the adults had shown at least one aggressive behaviour. Most acts were mild verbal outbursts.

Only one in twenty caused any physical injury. In other words, aggression is common, but serious harm is rare.

Tyrer et al. (2006) ran a similar survey the same year. They focused only on frequent or severe physical aggression and found 14%. The numbers look different, but G counted every single episode while F set a higher bar. Together they give a fuller picture: lots of minor acts, fewer dangerous ones.

Jennett et al. (2003) pooled earlier work and showed male sex, severe ID and autism raise risk. G’s raw numbers feed right into that meta-analysis.

de Kuijper et al. (2014) later added that more health problems mean more aggression. The 2006 paper set the baseline ‘how much’; the 2014 paper explained ‘who is at greater risk’.

When an adult with ID walks into your clinic, flip a coin: there is a fifty-fifty chance carers have seen aggression in the past year. Start with a five-question carer scale to sort mild venting from injury-risk behaviour. If injury risk is low, teach communication and coping skills first. If risk is high, add medical and psychiatric screens the same day.