Predicting and scaling hens' preferences for topographically different responses.

Six hens lived in a chamber with two jobs. One job was pecking a key. The other job was pushing a door.

Each job paid grain on its own VI schedule. The team changed the pay rates across sessions. They filmed where the birds spent their time and how many responses they made.

The goal was to see if the matching law could predict the birds' choices when the responses looked totally different.

Time and response ratios followed the matching law, but both under-matched a little. The key always pulled extra time and pecks.

The neat part: you could plug the key-versus-door difference into the equation as a fixed bias number. The predicted bias matched the real bias almost perfectly.

So, a key peck and a door push are not equal in the hen's world. The key is intrinsically easier or more fun.

Rilling et al. (1969) saw the same idea with pigeons and a simple left-right perch. They found a right-side bias. Dugan et al. (1995) now show the bias can also come from the type of response, not just where it happens.

Kazdin (1977) tested rats choosing between wheel running and sucrose. That study also treated the two responses as different commodities. The hen paper keeps the math but swaps species and topography, proving the rule travels.

Tan et al. (2014) moved matching into group foraging. The hen work stays with one bird, yet both papers confirm the law holds when you change ecological details. Together they tell us: whether alone, in groups, running, pecking, or pushing, the equation still talks.

If you run concurrent schedules in your classroom, clinic, or home, remember the response form itself can tilt the scale. A button press may out-pull a lever pull even when pay rates are equal. Measure the bias, then adjust the schedules or teach new topographies until balance shows up.