We have already met John Watson, the psychologist-turned-advertising-executive, who pioneered the idea that humans are essentially like any other animals, reacting predictably to external stimuli. Over the 1930s, a more famous scientist, B. F. Skinner, would take the idea further. He regarded free will to be an illusion and argued that our behavior is a fabric of responses to past stimuli, in particular the rewards or punishments that any behavior attracts. Understood this way, all animal behavior developed through a learning process he called "operant conditioning," whereby some actions are reinforced by positive consequences (rewards), others discouraged by negative ones (punishments). To demonstrate what he meant, he built the so-called Skinner Box or "operant conditioning chamber," wherein he subjected animals to various consequences and observed their conditioning. For instance, by giving a pigeon a food pellet whenever it pecked at a button, Skinner conditioned the pigeon to peck the button so as to be fed. He also showed that pigeons could be conditioned to do things like turn in a circle (by reinforcing left turns), or even play competitive Ping-Pong.* According to Skinner, we, too, in most aspects of our lives, are like pigeons pecking at a button to receive little snacks.

Tim Wu, The Attention Merchants, loc. 652