Do Pigeons Gamble? I Wouldn’t Bet Against It

Human gambling generally involves suboptimal choice because the expected return is usually less than the investment. We have found that animals, too, choose suboptimally under similar choice conditions. Pigeons, like human gamblers, show an impaired ability to objectively assess overall probabilities and amounts of reinforcement when a rare, highvalue outcome (analogous to a jackpot in human gambling) is presented in the context of more frequently occurring losses. More specifically, pigeons prefer a low-probability, high-reward outcome over a guaranteed low-reward outcome with a higher overall value. Furthermore, manipulations assumed to increase impulsivity (pigeons maintained at higher levels of motivation for food and pigeons housed in individual cages) result in increased suboptimal choice. They do so presumably because they function to increase attraction to the signal for the low-probability, high-reward outcomes rather than consider the more global probability of reinforcement associated with each alternative.