So Slashdot had this great article up over the weekend about the history of the slot machine. What I found interesting was the part about the psychology of it.
Slot machines take advantage of basic human psychology to maximize their appeal. In contrast to most other casino games such as blackjack or poker, playing a slot machine requires no skill, intellect, or decision-making ability. This non-threatening aspect is critical to the appeal of slot machines versus other casino games. In addition, there is no downtime while playing slots—the “action” is nonstop, and is designed to engross the player completely. Of course, the fundamental appeal of the slot machine, as in any other casino game, is the opportunity of winning and making a lot of money. However, slot machines are unique in that literally every coin a player puts in has a possibility of eliciting a huge payout, albeit a statistically negligible one. This aspect of slot machines provides initial and continued stimulus to the player; studies have shown that playing a slot machine activates dopaminergic neural pathways traditionally associated with pleasure or risk-taking. Beyond that, however, slot machines keep players engrossed through a psychological phenomenon known as operant conditioning.
Once a casino patron has been roped into initiating play at a slot machine, operant conditioning is perhaps the most powerful force that keeps him or her absorbed in the game. What psychologists call the “primary conditioning mechanism” is the inclusion of relatively small payouts in slot machine gameplay. These small payouts provide positive reinforcement to the player, a phenomenon that has been studied extensively by psychologist BF Skinner in experiments with rats. Skinner placed a rat in a box, with a lever at one end that would dispense a pellet of food. When, it its random behavior, the rat accidentally pushes the lever, the pellet of food reinforces this behavior. Soon the rat does nothing but push the lever repeatedly, expecting a pellet of food. The same principle applies to humans playing on slot machines; the positive reinforcement provided by the small payouts causes people to continue repeating the behavior. The frequency of payouts is precisely fine-tuned and optimized—a payout rate that is any higher than absolutely necessary cuts down on the casino’s profits.
Slot machines do not stop with a single primary conditioning mechanism. Secondary mechanisms augment the excitement and incentive to continue playing. The most important of these is the inclusion of a system in the machine that yields a high frequency of “near misses,” or situations in which the player believes they have almost won. For example, the slot machine often displays two out of the three jackpot bars, a tremendously stimulating event which has greatly reinforced the player’s behavior at no cost to the casino. The ringing bells, flashing lights, and other sounds from their own machine and nearby machines are other secondary conditioning mechanisms that keep the player stimulated.
