Grooming movements as operants in the rat.

Researchers watched rats in cages. They gave food each time the rat licked its paws or flanks. They did not give food for face washing. They counted how often each grooming move happened.

The goal was to see if everyday rat cleaning could work like a lever press. If food follows the move, will the rat do it more?

Paw and flank washing doubled when food came after the move. Face washing stayed flat. The body part mattered. Some 'free' moves were operants, others were not.

LATIES et al. (1965) saw tail-nibbling rise under a DRL food schedule. Both papers show odd rat moves can become operant when food is timed right.

Whitehead et al. (1975) got human stomach acid to rise or fall with cash rewards. That study widens the idea past rats: even hidden body responses can be operant.

Hart et al. (1974) found wheel running rose while lever pressing fell under long DRL. Their drop in licking looks like a mismatch with A et al.'s rise in grooming. The gap is the contingency: B et al. never tied food to licking; A et al. did tie food to grooming. When the move is directly fed, it grows.

Your client might twist hair, tap fingers, or rock. This rat work warns that only some topographies will strengthen with reward. Test each one. If finger tapping grows but hair twisting stays flat, shift the contingency to the move that actually changes. Do not assume all 'stereotypy' will respond the same way.