The American Heritage Dictionary defines a bribe as "Something, such as money, offered or given to induce or influence a person to act dishonestly." As such, other than situations in which a positively reinforced behavior is dishonest or illegal, positive reinforcement cannot be properly identified with bribery.
We live in a culture in which using positive reinforcement to motivate people is less familiar than using punishment and other methods of aversive control (Sidman, 1989). Therefore, when someone proposes using positive reinforcement in a context where aversive control is typically used, there is a tendency to compare positive reinforcement to bribery because, as products of an aversive-control culture, we lack a context for understanding the use of positive reinforcement. To describe positive reinforcement, we therefore turn to the nearest available metaphor, that of bribery, even though it is a poor metaphor.
Although there are certain conditions that can cause rewards to diminish the intrinsically reinforcing value of an activity, rewards do not have a general or pervasive harmful influence on motivation to perform a task. Rewards can have a negative influence on motivation if (a) a high-interest task is involved; (b) rewards are tangible; and (c) rewards are not closely tied to a performance criterion. These problems are typically avoided in behavior-analysis interventions that do not provide reinforcers for behaviors already occurring at an adequate rate, use tangible rewards only as a transition to natural reinforcers, and use clear and specific criteria for reinforcement.
The controversy surrounding the supposed harmful influence of rewards is unfortunate some parents and care givers have been misled to avoid, for example, praising children because they think this might somehow be harmful. Praise is a particularly powerful positive reinforcer that helps children learn. Meta-analyses of studies have shown that praise increases the intrinsic interest people have in activities even after praise is no longer forthcoming (Cameron, Banko, and Pierce, 2001). Although any reinforcer can be over used and interfere with the transition to natural reinforcers, a more serious problem in our culture is with the failure to use praise when children are behaving well (i.e., "catch 'em being good"). The maxim "Catch 'em being good" sounds anomalous to us because we are steeped in a cultural tradition of aversive control with children, with catching them being bad.
Note that a general goal of positive reinforcement procedures is to ensure that desirable behavior are eventually maintained by natural reinforcers. Therefore, when contrived reinforcers are used to induce desirable behaviors, behavior analysts (e.g., Grant & Evans, 1994; Martin and Pear, 1992) recommend programs to shift to maintenance of behaviors to natural reinforcers. Grant and Evans (1994) suggest that identifying natural reinforcers can be done by examining what reinforcers maintain the behavior of experts in a given subject matter domain. So, for example, the behavior of most scientists on the cutting edge of a field of knowledge is maintained by the reinforcers associated with discovery, with tying together known facts, the opportunity to move on to new research questions posed by current discoveries, and so forth. Attention and admiration from colleagues probably plays an important role as well, even for experts. Whereas a child's or a student's incipient scientific activities are often maintained by course grades, it is important in the longer run to establish natural reinforcers for scientific behavior. In media coverage of behavior-analysis programs, much emphasis is placed the use of extrinsic and tangible reinforcers, but it should be understood that with most populations, such reinforcers are very often used to get weak behavior to occur with the expectation than once a reliable performance is established, the extrinsic and tangible reinforcers will be faded out in favor of natural reinforcers. In the same sense, grades are an important feature of schooling, but wise educators use grades with the expectation that there will be a transition to natural reinforcers for the behaviors acquired as a part of schooling.
For reviews of research in this area, see Cameron, et. al. (2001), Eisenberger, Pierce, and Cameron (1999), Cameron and Pierce (1994) and Eisenberger and Cameron (1996). The myth that rewards have generally and pervasively harmful effects on motivation has perhaps been most widely propagated by Kohn (1993).
It is said that flattery will get you everywhere, and the psychological principle behind flattery is positive reinforcement. The American Heritage Dictionary defines the primary meaning for the verb "to flatter" as "to compliment excessively and often insincerely".
Praise is such a powerful reinforcer that it gives rise to abuse, and for this reason the concept of flattery carries a negative meaning. It is of course often necessary to examine the motives behind flattery and not take it at face value.
Behavior analysts generally do try to use more praise than is the norm in order to harness the power of positive reinforcement and make the world a more pleasant place in which to live. However, most behavior analysts have adopted a rule of thumb in employing praise. It is to avoid using praise in a forced manner and instead only praise when you think to yourself that someone has done something well or at least better than they have done before. In this way praise is sincere and flattery is avoided but at the same praise is more generous because instances in which we would ordinarily only think well of another person are turned into instances of overt praise. As such the rule for praise, "if you think it, then say it" allows you to praise more often without the insincerity associated with flattery.