When many people think of casinos, they picture blackjack tables or roulette wheels. But slot machines are now the heart of the gaming industry, bringing in up to 85 percent of profits. And they’re surprisingly addictive, says MIT cultural anthropologist Sarah Schull. She spent 15 years in Las Vegas tracking the evolution of video gambling and discovered that casinos have drawn on psychology to make their games as hard-to-leave as possible.
Schull describes how the game’s algorithms manipulate the players’ decisions to keep them playing. Advances in payment systems have also been crucial, enabling players to feed bills or cards with magnetic strips into the machines without having to stop to reload. But it’s the speed and repetitiveness of the game that has made slots so enticing, she says. Each spin can bring in hundreds of values, and every one offers another chance to win.
It’s the frequency of near misses that triggers gambling behavior, according to Skinner’s theory. Specifically, when audio-visual stimuli that correspond to loss approximate those of a win, they acquire conditionally reinforcing properties. This is why, for example, hearing “cherry-cherry-lemon” on a standard slot machine might prompt some players to continue gambling.
In a series of experiments, Schull and her colleagues manipulated the frequency of near-miss stimuli on four-reel slot simulations that participants played for money. They then tested how that impacted the frequency of their gambling responses during extinction. They found that the higher the density of near-miss stimuli, the greater the frequency of gambling persistence. However, there are several concerns with these results.