What happens when you pay two monkeys unequally?

Okay, so how reproducible is this?

Because I've seen many cases of single-primate case studies that turned out to be not reproducible as others attempted to do it, — in particular those that found human-like behavior in nonhuman primates.

It feels as though every researcher that wants to find human-like behavior in non-human primates can find it, and every research that desires that it isn't there can find it's nonexistence.

I have two cats trained to do specific behaviors to get fed -- but different behaviors, and lately there has been a lot of politics between the two of them (e.g. one of them will signal to get food not because they want to eat it but because they want to make a scene with the other cat.)