The term Neo-Pavlovian derives from the Russian scientist Ivan Pavlov. Pavlov is well known for his discovery of "the conditioned reflex".
An innate reflex is an instinctive and unlearned reaction to a stimulus, for example, blinking and yawning. A conditioned reflex, on the other hand, is learned, either through negative or positive stimuli. For example, the fear of snakes is a learned reflex: young children are taught to fear snakes by the reaction of their parents, who will scream and pull their child away.
Pavlov used his dogs to demonstrate this reflex. Firstly, he would ring a bell as a sign for the dogs that he'd prepared their food. Over time he began to ring the bell without the food; the dogs would salivate profusely in association with the ringing bell even when the actual sight or smell of food was not there. Pavlov regarded this salivation as being a conditioned reflex.