Intra-individual factors influencing efficacy of interventions for stereotyped behaviours: a meta-analysis.

Martin (1995) pooled earlier single-case reports on stereotypy in people with intellectual disability.

The team asked two questions: does client age change how well an intervention works, and does the form of the stereotypy matter?

They used meta-analysis to turn small graphs into one big picture.

Younger participants had clearer drops in stereotypy after treatment.

Some topographies, like hand flapping, responded better than others, such as rocking.

In short, age and form of the behavior both steer success.

van der Miesen et al. (2024) later looked at self-injury in the same group and found huge reductions. Their paper supersedes Martin (1995) by adding newer data and showing caregivers can run the plan at home with the same punch.

Vanderkerken et al. (2013) extends the idea to autism. They found vocal stereotypy drops most when you mix antecedent and consequence steps, backing the claim that form matters.

Faso et al. (2016) tracked babies and toddlers. Early stereotypy predicted later self-injury, giving a real-world reason to act quickly while clients are still young, just as Martin (1995) hinted.

You now have three linked facts: treat early, match the plan to the topography, and expect caregiver-led sessions to work. Start by writing the child’s age and the exact form of stereotypy on the plan sheet. Pick procedures tested for that form, run them soon, and teach parents the same steps.