by Vivek Wadhwa
In the 1930s, psychologist B.F. Skinner put rats in boxes and taught them to push levers to receive a food pellet. They pushed the levers only when hungry, though. To get the rats to press the lever repeatedly, even when they did not need food, he gave them a pellet only some of the time, a concept now known as intermittent variable rewards. Casinos have used this same technique for decades to keep us pouring money into slot machines. And now the technology industry is using it to keep us checking our smartphones for emails, for new followers on Twitter, or for more “likes” on photographs we posted on Facebook.