Effects of reinforcement scheduling on simultaneous discrimination performance.

Pigeons pecked two keys to earn grain. The keys lit up with colors. The birds had to pick the correct color to get food. The team changed how often grain followed a correct peck. They kept score of how many pecks each bird made and how many were right.

When grain came faster, the birds pecked more. When grain came slower, they pecked less. Yet the percent of correct pecks stayed the same. The schedule controlled effort, not accuracy. The birds still knew which color was correct.

Todorov et al. (1984) ran a similar pigeon test. They swapped grain size instead of grain timing. Again, frequency beat size in driving pecks. The 1967 null-accuracy result held.

Thomas (1974) moved the setup to college students. People did not follow the matching law like pigeons. Humans picked the rich side 15–20% less than the math said. Same schedule rules, different species, different outcome.

Farrant et al. (1998) worked with rats learning a new lever. Fast grain every 15 s sparked more levers than constant grain. The 1967 idea extends to acquisition: lean but steady beats rich but crowded.

You can change how hard a client works without hurting accuracy. Thin the schedule to boost persistence. Keep the SD the same to protect stimulus control. Check for species or phase differences before you port animal data to your case.