Choice performance in several concurrent key-peck treadle-press reinforcement schedules.

Wheatley et al. (1978) let pigeons pick between two VI schedules. One schedule needed a key peck. The other needed a treadle press. The birds could switch any time. The team tracked how choices lined up with the reinforcer rates.

This setup tested if birds would favor key pecking just because it is a common pigeon move.

The birds undermatched. Their time and response ratios leaned toward indifference, not toward the richer schedule. Key pecking held no special edge.

Even with two very different moves, the birds still showed the usual undermatching curve.

Durand (1982) saw overmatching when reinforcer duration changed. Wheatley et al. (1978) saw undermatching when response form changed. Same two-key VI layout, opposite direction of deviation. The difference is the variable: duration pushes ratios past matching, while response form pulls them short of matching.

Bensemann et al. (2015) added two more choices and steady-state conditions. They found the constant-ratio rule held. Wheatley et al. (1978) only used two choices, yet both studies keep the reinforcer ratio as the main driver, not the response details.

Najdowski et al. (2003) flipped delays daily and saw rapid reallocation. Wheatley et al. (1978) kept schedules stable but swapped the required move. Together they show choice adapts quickly whether the change is in delay or in topography.

For your clients, do not assume a hand tap will always beat a foot press. If the reinforcer rates are equal, topography differences may not matter. Watch the obtained reinforcer ratios first, then adjust the schedules, not the response form, when you want to shift preference.