Zeno tried to train his potbellied pig to pick up the newspaper on the doorstep and bring it into the house. however, the pig pushed the paper with his snout into the garden, even though this behavior would not be rewarded. it appears that zeno's attempt to operantly condition his pig has been subject to:

Zeno's attempt to operantly condition his pig has been subject to: I believe the answer is: instinctive drift
instinctive drift refers to the automatic behavior that would intervene with a certain learned response. 
For example, in the past decades, mankind have been advice to avoid hostile and agressive behavior. But when enraged, most people would blatantly engage in aggressive behavior without fearing the consequences.