Clicker Classic: Can Reinforcers Be Too Powerful?

Eddy was hesitating, as I see it, over the possibility that using these very powerful reinforcers could allow you to develop animals that would work long past the humane level. He mentioned pigeons on long schedules that actually crack their beaks, pecking. I don't see that as manipulation or oppression, but as cooperation and delivery beyond the call of duty in a pinch; on a daily basis, I wouldn't ask for that.