ample, when two same-type fruits appear in a slot machine, there is a brief period of excitement and thrill as one hopes for the third needed to win the jackpot. Even if the third fruit does not quite line up with the other two, there is still some thrill from the thought of nearly winning. Not surprisingly, some slot machines are designed to ensure a higher than chance frequency of near misses. Such reinforcement can occur at no expense to the casino.
Finally, the casino environment itself provides reinforcing effects, such as flashing lights, ringing bells, bright lighting and color schemes, and the clanging of coins as they fall into the winning collection bins of slot machines (Knapp, 1976). People are often "primed" when casinos give away rolls of free coins, or allow people to gamble without charge for limited periods of time. For all of these reasons, excessive gambling may be viewed as a conditioned response to powerful reinforcers.
In response to the conceptual confusion affecting understanding of addictive and impulse disorders generally, Jacobs and others have emphasized the need for an overriding conceptual framework—a credible and testable theory, supported by an empirically derived database—that could clearly address the causes and the course of addictive behaviors (Jacobs, 1987, 1988; Shaffer et al., 1989). Jacobs has proposed an interactive model of addiction, defining it as a dependent state that is acquired over time by a predisposed person in an attempt to relieve a chronic stress condition. Using pathological gambling as the prototype addiction, he posited that two interacting sets of factors (an abnormal physiological arousal state and childhood experiences resulting in a deep sense of personal inadequacy and rejection) in a conducive environment may produce addiction to any activity or substance that possesses three attributes: (1) it blurs reality by temporarily diverting the person's attention from the chronic aversive arousal state, (2) it lowers self-criticism and self-consciousness through an internal cognitive shift that deflects preoccupation from one's perceived inadequacies, and (3) it permits complimentary daydreams about oneself through a self-induced dissociative process.