Flinging birds at pigs and moving jelly beans around a little screen are not human instincts. Game designers create the urge to do those things for hours at a time.
"From the way the games are designed to help us start playing the game, to the way they keep us coming back to the game, to how they involve our friends in the game — all of these things have underpinnings in consumer psychology," says game consultant Nir Eyal.
