Effects of Token Reinforcement on Physical Activity and Intrinsic Motivation

Background/Purpose: Although effective in improving physical activity (PA) behavior, extrinsic rewards have been criticized for the potential detriment to one’s intrinsic motivation for engaging in the activity for which one was rewarded. However, there is conflicting research on intrinsic motivation in fields outside of PA; when extrinsic rewards have been introduced and subsequently withdrawn systematically, intrinsic motivation can increase. It is unknown how the use of extrinsic rewards, when used to reinforce PA behavior, will impact intrinsic motivation when systematically withdrawn. Therefore, the purpose of this study was to examine the effects of extrinsic rewards, administered as a token economy on two schedules of reinforcement, a fixed interval (FI) schedule and a variable interval (VI) schedule, on the intensity of riding a stationary bicycle as well as its influence on intrinsic motivation for engaging in PA. 

Method: Ten participants were asked to ride a stationary bike for several 20-minute sessions. During the baseline phase, participants rode for 20 minutes without extrinsic reward. Mean revolutions per minute (RPM) were calculated. Once a stable baseline pattern emerged, the token economy was introduced. Participants on the FI schedule were awarded one token for every minute they rode above 10% of their mean baseline RPM. For those on the VI schedule, the rate of reinforcement was systematically decreased. During the first token session, participants were awarded one token for every minute above 10% of their baseline mean; session two was increased to 1.5 minutes. Each subsequent token session was increased by 30 seconds, making it increasingly difficult to earn tokens. After each token session, participants were given the opportunity to exchange their earned tokens for a gift card. 

Analysis/Results: Mean RPM for baseline and token sessions were plotted on a graph and inspected for response differentiation. The Situational Motivational Scale (SIMS) was administered to participants before and after the intervention to assess changes in intrinsic motivation. Both FI and VI schedules were effective in increasing the intensity with which participants rode the exercise bike. Most participants who were given tokens on the FI schedule decreased in their intrinsic motivation score. However, all VI-scheduled participants’ intrinsic motivation increased or remained constant. 

Conclusions: Token economies can be useful in improving the physical activity of those who are reinforced. However, to improve performance while increasing or maintaining intrinsic motivation, physical activity professionals should consider introducing extrinsic rewards to improve the behavior and subsequently withdrawing them systematically.