Demand for food on fixed-ratio schedules as a function of the quality of concurrently available reinforcement.

E and coworkers worked with pigeons on fixed-ratio (FR) schedules. The birds had to peck a key many times to earn a food pellet.

A second key always gave sweet sucrose water for one peck. The team raised the FR pellet requirement and watched how pellet earning changed.

Pellet earnings dropped as the FR got bigger. The drop was sharpest when the sweet water was present.

In other words, a high-quality reinforcer next door made the birds give up on pellets faster. Demand was elastic when a better option existed.

Bachman et al. (1988) later showed the same reinforcer-competition idea using accessibility instead of quality. They raised the chance of getting the poor option and saw more acceptance, but when they shortened search time for that option, acceptance fell. Both studies say the same thing: nearby good stuff changes how hard animals will work.

Grosch et al. (1981) looked at signaled versus unsignaled delays in a concurrent chain. Birds strongly preferred the side that told them when reinforcement was coming. This seems to clash with the 1977 finding—why would birds keep working if the delay signal itself is a competing stimulus? The answer is in the type of competition: the 1977 paper used a different, higher-quality reinforcer, while the 1981 paper kept quality equal and only changed information. When quality is the same, information wins.

Kuroda et al. (2014) added that full delay signals protect accuracy, partial signals hurt it, and no signals hurt it most. Together these papers show that both what is available and how it is signaled control responding.

If you give a client a so-so reinforcer while a favorite toy sits on the shelf, response effort will drop. Either remove the competing favorite, raise the quality of the task reinforcer, or make the task schedule leaner. Check your room for hidden 'sucrose' before you call a skill 'too hard'.