Psychologists have long tried to understand
Before Zeiler could change the world, he had to work out the best way to deliver rewards. One option was to reward every desirable behaviour. Another was to reward those same desirable behaviours on an unpredictable schedule, creating some of the mystery that encourages people to buy lottery tickets. The pigeons had been raised in the lab, so they knew the drill. Each one waddled up to a small button and pecked persistently, hoping that the button would release a tray of Purina pigeon pellets. During some trials, Zeiler would programme the button so it delivered food every time the pigeons pecked; during others, he programmed the button so it delivered food only some of the time. Sometimes the pigeons would peck in vain, the button would turn red, and they would receive nothing.
