Antecedent manipulations in a tangible condition: effects of stimulus preference on aggression.

The team worked with kids who had autism. They wanted to see what happens when you take away favorite toys.

Each child ranked toys from most to least liked. Then the adults removed either the top toy or a so-so toy.

They watched how much aggression showed up in each case.

Taking the most loved item sparked the highest aggression, even when other good toys sat right there.

Taking a so-so item still caused some aggression, but the level stayed moderate.

The result was a wash overall because the two pulls cancelled each other out.

Carr et al. (2002) ran a close cousin study. They gave free access to highly preferred items during a functional analysis. Problem behavior tied to attention dropped. Both papers show the same rule: preferred items act like a switch for problem behavior.

Edrisinha et al. (2011) pushed the idea further. They turned the establishing operation (EO) on and off before sessions. When the EO was on, challenging behavior rose even though no reinforcement followed. Their data back up Richman et al. (2001): mess with the EO and you move the behavior.

Borrero et al. (2005) looked at reinforcer choice inside FCT. Some kids wanted only praise, others wanted praise plus escape. Their work reminds us that preference matters in treatment, not just in assessment.

Before you run a tangible condition, rank the items. Skip the top pick if you need a cleaner test. During treatment, keep the most loved stuff available or teach a request first. You will avoid spikes that blow up your session.