Feedback Properties of "Self-reinforcement": Further Evidence

Transcription

1 BEHAVIOR THERAPY 14, (1983) Feedback Properties of "Self-reinforcement": Further Evidence LEONIDAS CASTRO GLORIA CAJIAO DE PI~REZ DORIAN BUSTOS DE ALBANCHEZ EDUARDO PONCE DE LE6N Universidad Cat61ica de Colombia The effects of externally and self-administered stimuli of opposite valences were compared against a no feedback condition in a weight reduction program. After being trained in behavioral self-control methods for losing weight, subjects in a positive feedback condition were paid for weight losses, those in the negative feedback condition had either to send money to their least preferred ideological group or to destroy money contingent on weight loss and were paid for weight gains, and those in the no feedback condition self-monitored their eating behavior. These procedures were self-administered in a subsequent phase. Although all conditions produced significant weight losses, the negative feedback procedure resulted in significantly more weight reduction than the other two procedures, both through treatment and maintenance. These results are not consistent with incentive views of self-reinforcement but favor formulations in terms of feedback salience. Implications for a need to reformulate current theories of self-control and to pursue research in other directions are discussed. The notion of self-reinforcement, as self-administration of freely available reinforcers conditional upon the performance of specific responses, is central to several current theories of self-control (Bandura, 1976, 1981; Kanfer & Karoly, 1972; Thoresen & Mahoney, 1974). From an empirical perspective, self-reinforcement has been widely investigated in laboratory settings (Bandura & Kupers, 1964; Bandura & Perloff, 1967; Kanfer, Bradley, & Marston, 1962; Kanfer & Duerfeldt, 1968; Mahoney & Bandura, 1972). At an applied level, it has been shown to be effective with a diversity of problem behaviors (Felixbrod & O'Leary, 1974; Fuchs & Rehm, 1977; Mahoney, 1974). The authors wish to express their appreciation to Howard Rachlin, Jos6 Antonio Sfinchez, Carlos Pereira, William Hutchison, and Elizabeth Angel for their helpful comments and suggestions. Reprint requests should be sent to Leonidas Castro, Faculty of Psychology, Catholic University of Colombia, Apartado , Bogot,-i, Colombia, South America /83/ $ 1.00/0 Copyright 1983 by Association for Advancement of Behavior Therapy All rights of reproduction in any form reserved.

2 SELF-REINFORCEMENT AND WEIGHT CONTROL 673 In spite of the considerable amount of empirical data, the mechanism of "self-reinforcement" is far from clear and has been the focus of an active theoretical controversy. On one hand, mediational theorists attribute to "self-reinforcement" incentive properties which are said to replace the absent immediate external reinforcers (Bandura, 1976, 1981; Mahoney, 1976; Thoresen & Wilbur, 1976). On the other hand, nonmediational theorists conceptualize the action of "self-reinforcement" as due to its informational value in making the relationship between the response and the delayed reinforcer more salient (Catania, 1975, 1976; Gewirtz, 1971; Goldiamond, 1976a, 1976b; Rachlin, 1974; Stuart, 1972). 1 Clarification of this controversy would have important implications both for theory and application. Castro and Rachlin (1980) attempted to separate incentive from informational properties of self-reinforcement in a weight reduction program. The effects of two self-administered stimuli with approximately equivalent salience but opposite affective value (taking money vs. paying money for losing weight) were compared with a condition of noncontingent payment and a waiting list control. All treatment groups lost weight and there were no significant differences among them. Comparing these results with those of a previous study (Mahoney, 1974), the authors challenged the theory that the effectiveness of self-reward depends on its positive affect. Had that been the case, the self-reward condition would have been more effective than the other two. The above study was called into question by Bandura (1981). First, he claimed that the negative stimulus used in the self-punishment condition could not be punishing, since paying for a service in everyday life would hardly be perceived as negative. Second, the lack of a control group without monetary exchange did not allow drawing conclusions about the effects of "monetary cues." Third, a condition of externally administered reward was not included. The present study aims at further clarifying the role of intermediate stimuli in self-control. We compared the effects on weight loss of presenting positively valued stimuli, negatively valued stimuli, and no additional stimuli in a weight reduction program. We tried to follow Bandura's suggestions. For each subject we assessed the negative value of several potentially aversive stimuli and selected the most aversive one. Second, we included a control group without "monetary cues." Third, we used an externally administered procedure followed by a subsequent phase of self-administration. METHOD Subjects A total of 40 subjects were selected for this study from 128 applicants to a weight reduction program advertised in the major newspapers of the i For an extensive review of the theoretical analyses and empirical studies on self-reinforcement, see Castro and Pereira (1983).

3 674 CASTRO ET AL. city of Bogotfi. Applicants not meeting the following criteria were not accepted to the program: at least 18 years old, a minimum of 15% overweight according to the Fogarty International Table, not participating in other weight reduction programs, not taking drugs related to weight loss, and not having a physical condition resulting in weight changes. Subjects admitted to the program were between 18 and 48 years old, of both sexes, and from professional level families. They were divided into three blocks (high, medium, and low) on the basis of their baseline percentage of overweight, and from these blocks were randomly assigned to one of the following three groups at the beginning of the experimental phase: Group!, Positive feedback (n = 13, all females, Mean initial weight = lb., kg); Group 2, Negative feedback (n = 14, 11 females and 3 males, Mean initial weight = lb, kg); Group 3, No feedback (n = 13, 11 females and 2 males, Mean initial weight = lb, kg). From the total number of subjects entering the program, all except two (belonging to Groups 1 and 2) remained through the end of the study. Experimenters Two candidates to the professional psychologist degree from the Catholic University of Colombia, both females with clinical experience, were the experimenters in this study. They directed individual weigh-ins, gave instructions and collected data from all subjects. The only group session was led by the principal investigator, a PhD clinical psychologist with previous experience in similar programs. Procedure All subjects had identical treatments during the first two phases of the study, self-monitoring and self-monitoring plus stimulus control, and were assigned to one of three experimental conditions at the end of the second phase. Baseline assessment and initial meeting. At the baseline interview, subjects were individually assessed with respect to weight and height. Those selected on the basis of the screening assessment attended a 2- hour group session in which general goals of the program and instructions for self-monitoring and calorie counting were explained. A handout of self-monitoring and calorie counting were explained. A handout of selfmonitoring instructions, 2 calorie counters of local foods, and self-recording forms for the 1st week were distributed. All subjects were required to pay a fee for the whole program equivalent to $30. Self-monitoring phase (2 weeks). Instructions for this phase were read during the initial group session and included procedures for self-observation and self-recording of the kinds and amounts of food eaten during the day, caloric value of each item, place and duration of eating, and emotional state. Subjects were asked to fill in a daily self-report card 2 A more detailed description of this material is available from the senior author upon request.

4 SELF-REINFORCEMENT AND WEIGHT CONTROL 675 handed out at the weekly weigh-ins. At experimental sessions during this phase, experimenters weighed each subject individually, provided information on weight status without specific instructions, and avoided any comment on weight changes. Subjects did not have any contact with experimenters between weigh-ins. Stimulus control phase (2 weeks). At the second weigh-in subjects were given, in addition to the standard procedures described above, detailed instructions on stimulus control procedures for changing eating habits (Ferster, Nurnberg, & Levitt, 1962; Stuart & Davis, 1972). Subjects were also given written instructions containing specific rules for narrowing stimulus control, interrupting the behavioral chain of eating, and increasing commitment. Group I: Positive feedback (4 weeks). At the fourth weigh-in, in addition to standard procedures used in the former weigh-ins, subjects under this condition were informed that for the following 4 weeks they would be rewarded for weight loss with an amount equivalent to $1 per pound lost since the previous weigh-in. At weigh-ins during this phase, subjects were paid by the experimenters according to progress. If no weight loss occurred, there was no monetary reward. Subjects were instructed to continue the procedure of self-monitoring and stimulus control explained in the first phases. Group 2: Negative feedback (4 weeks). In order to assess in advance the degree of aversiveness of potential stimuli to be used in this condition, at the third weigh-in, subjects assigned to this group were administered a questionnaire exploring attitudes towards the following topics: (a) political parties in Colombia, (b) candidates for presidential elections to be held 1 month later, and (c) religious groups. The degree of preference was determined both through Likert scales and ranking order of different alternatives within and across dimensions. Considering the possibility that some subjects would not show strong enough attitudes towards any of the former topics, a fourth dimension was assessed: degree of aversiveness of having to destroy money of their own. On the basis of the answers to the four categories, a 4 4 matrix was generated for each subject. In order to make these scores comparable, they were interpreted as distances between pairs of stimuli, where higher scores meant closer distances and therefore higher similarity (acceptance) between stimuli. As a consequence, data were transformed according to the Young-Householder theorem (Torgersson, 1958) and from this transformation, stimuli with the lowest value (highest rejection) were selected to be used for each subject in this experimental condition. Destroying money was thus selected as the least valued stimulus by six subjects, presidential candidate by five subjects, and political party by one subject. Religious group was not selected as most aversive by any subject. In addition to standard procedures used in the former weigh-ins, subjects under this condition were informed at the fourth weigh-in that, for the following 4 weeks, their weight gain or loss would influence what happened to a proportion of the fee paid at the beginning of the program:

5 676 CASTRO ET AL. for each pound lost an amount of money equivalent to $1 would be sent to their least preferred political party, to the presidential campaign of their least preferred candidate, or that they would have to destroy the corresponding amount of money in the presence of the experimenters. The particular instruction read to each individual subject was based on the results to the attitude questionnaire. If they did not lose weight they would recover $1, and if they gained weight they would recover one additional dollar per pound gained. At weigh-ins during this phase, if there were pounds lost, and after informing the subject of weight changes since previous weigh-ins, the experimenter either deposited the corresponding amount of money in a sealed box marked with the name of the political party or the presidential candidate or delivered the bills to the subject and asked him/her to cut them with a pair of scissors in pieces no bigger than one inch, therefore guaranteeing the impossibility of reconstruction. In the case of no weight Change or weight gained, the experimenter paid the subject with the corresponding amount of money. Group 3: No feedback (4 weeks). Subjects in this condition were asked to follow the same instructions used in the previous phase, self-monitoring and stimulus control of eating habits. No additional instructions in terms of monetary exchange were given at this point. Self-administration (4 weeks). At the 8th weigh-in, all subjects were instructed to administer for themselves for the following 4 weeks the program they had been following. During this phase, no contact with the experimenters was scheduled. Instructions included enforcement of selfmonitoring and stimulus control procedures and selection of one specific day each week to weigh themselves at home in order to record and graph weight changes. In addition, different instructions were given to subjects in each of the feedback conditions. Subjects in the self-administered positive feedback condition were asked to put some money apart, in a "weight reduction box" at the beginning of this phase. At home weekly weigh-ins, they would take a certain amount of money proportional to weight loss, as a self-reward for progress, which was equivalent to the amount used in the previous phase: $1 per pound lost. This money was to be spent as soon as possible in a special "treat" for themselves. At the end of the 4th week, the remaining money was to have been given away and not spent for personal benefit. Subjects in the self-administered negative feedback condition were asked to put in a "weight reduction box" a certain amount of money proportional to weight loss ($1 per pound) at their home weekly weigh-ins. At the end of the 4 weeks, all money collected was to be taken to the experimental session and destroyed in the presence of the experimenters. Maintenance (4 weeks). At the 12th week subjects attended the ninth experimental weigh-in. Subjects were informed that from that point on, they would be using the procedures completely on their own. Even though self-monitoring and control of eating habits were enforced, unlike the previous phase, no specific instructions regarding feedback were given

6 SELF-REINFORCEMENT AND WEIGHT CONTROL 677 to subjects in the two feedback conditions. Rather, they were told to decide which procedures to use on a permanent basis. With the purpose of partial replication, at this point the externally administered negative feedback procedure was implemented with subjects who had been in the no feedback condition in previous phases. Unlike the other two groups who remained without contact with experimenters, subjects in this group were scheduled for weekly weigh-ins with the experimenters for the following 4 weeks. The negative feedback procedure was identical to the one administered to Group 2, except that since presidential elections had already taken place, all subjects had to destroy money according to weight loss. At week 16, an individual followup session was held for subjects in Groups 1 and 2, and subjects in Group 3 were instructed to continue using the program on their own without specific instructions regarding feedback. RESULTS Overall Analysis In order to assess the effects of treatment throughout the program, data were analyzed by way of a three-way analysis of variance (ANOVA) with two between-subject factors (treatment and blocks) and one withinsubject factor (phases). The adequacy of the model for explaining a high proportion of variance was evidenced by a determination coefficient R 2 =.864. The ANOVA yielded a significant main effect for repeated measures, F(3, 87) = 84.74, p <.001, indicating the effectiveness of the weight reduction program for all groups. Main effects for the treatment variable were also significant, F(2, 29) = 5.65, p <.01, indicating a systematic difference in variance between experimental groups. Duncan multiple range tests showed that the negative feedback group differed significantly from the other two groups (p <.05), although the latter did not differ from each other. Main effects for blocks did not reach the significance level. Significant effects were also found for the treatment x weeks interaction, F(6, 87) = 40.70, p <.001, reflecting differential changes in weight loss between experimental groups across successive phases of treatment. Overall results are summarized in Fig. 1. Effects by Phases In order to assess the relative contribution of each of the sequential interventions across time, separate analyses were carried out for each phase. As expected from the experimental design, there were no significant differences among groups for the first baseline phases. However, a significant main effect for repeated measures was already present at this point, F(2, 29) = 17.52, p <.001. Significant group effects did show at the end of the third phase (externally administered feedback), F(2, 29) = 4.65, p <.05. This difference became more pronounced in the following phase (self-administered feedback), F(2, 29) = 28.01, p <.001.

7 678 CASTRO ET AL. 0 S=. M SC External Self- Maintenance I Administr. Administr. 2 " ".,,..Fe..e. db.~'ack + [] i~ ~.. Feedback -- 4 No Feedback A o.. lo ill,, 1 " 14 \,., WEEKS FIG. 1. Mean pounds lost per week for each group through self-monitoring (SM), stimulus control (SC), external administration of feedback stimuli, self-administration of feedback stimuli and maintenance. From week 12 on, the negative feedback condition was implemented for the group with no feedback in previous sessions. With the purpose of assessing the amount of weight change between weeks 12 and 16 and the degree of significance of the effect of negative feedback on subjects previously in the no feedback condition, a one-way ANOVA on change scores between weeks 12 and 16 was performed for all groups. This analysis yielded a significant effect, F(2, 33) = 4.20, p <.05. A Duncan multiple range test revealed that only changes in Group 3 were significant with respect to the other two (p <.05), therefore replicating partially the effects found across groups. DISCUSSION The present study showed that low-valued stimuli, either externally or self-administered, contributed to significantly more weight loss than positively valued stimuli or than self-monitoring alone. This effect was partially replicated when the negative feedback procedure was introduced to the group without feedback. When feedback instructions were discontinued at the end of the experimental phase, there was a slight weight increase in subjects previously under negative feedback which was not

8 SELF-REINFORCEMENT AND WEIGHT CONTROL 679 shown for those previously under positive feedback, suggesting either specific effects of negative feedback or greater likelihood of subjects under positive feedback to continue using these procedures on their own. Essentially, these results replicate and support those of a similar previous study by Castro and Rachlin (1980). In the context of behavior maintained by delayed consequences, such as dieting, intermediate stimuli like "self-rewards" for progress might have informational and incentive properties. In this study, empirical selection of low-valued stimuli for each subject in the negative feedback group rules out the possibility that these had been functioning as incentives. Therefore, the superiority of the negative feedback procedure over the other two does not support the notion of self-reward being effective because of its incentive properties in motivating behavior (Bandura, 1981). Rather, the demonstrated effectiveness of "self-reward" must be due to factors other than reinforcement. The attribution of reinforcement properties to self-administered stimuli stems from a basic misunderstanding of the concept of reinforcement in contemporary behavior theory. The notion of "self-reinforcement" is derived from traditional conceptualizations ascribing universal reinforcing properties to certain classes of events, the reinforcers. However, following Premack (1965, 1971) current views emphasize the relative notion of reinforcement as a kind of relationship, not necessarily contiguous between environmental and behavioral events (Rachlin, 1976; Staddon, 1979). From this perspective, any given activity may act as a reinforcer or punisher depending on the contingency relationship between instrumental and contingent activities. As a corollary, for any event to be considered a reinforcer, a condition of deprivation or restriction is required, meaning that such an event cannot be freely available (Timbedake & Allison, 1974). Since self-reinforcement in order to be self-administered requires free availability, the concept is inherently contradictory. Consequently, in the case of weight control the only reinforcers for dieting are those events from which the person is deprived (i.e., are not freely available), which require dieting as a necessary condition to occur, and which come later in time--namely, social approval, different appearance, better health, and some others accompanying weight loss. The intermediate "rewards" are actually informative cues which cause the person to pay more attention to his or her own behavior. Our findings are consistent with the above conceptualization. The negative feedback might have been effective in maintaining dieting because the stimulus we used, besides being more aversive, was also more informative. Similarly, the superiority of the negative over the positive feedback procedure can be due to differences in salience, not in affective value between stimuli. The salience involved in being paid $1 per pound lost is almost certainly lower than that involved in destroying a dollar bill per pound lost. By the same token, getting $1 per pound lost might not add much information to that obtained in not getting paid at all, which would explain the lack of differences between positive feedback and self-

9 680 CASTRO ET AL. monitoring alone. Thus, stimuli affect behavior not only because of variables inherent in the stimulus, but also because of the contextual effects involved in the relationship with other stimuli delayed in time. That is, only within the context of delayed reinforcement may a negative stimulus act to increase behavior. Out of this context, it will act in the opposite direction. However, this effect depends on the relative value of the intermediate stimulus with respect to that of the delayed reinforcer. In fact, had we increased the negative value of the intermediate stimulus beyond an optimum point we might have found a true punishment effect. Nevertheless, such a situation would not be, by definition, one of self-control. The fact that individuals cannot directly provide themselves with their own reinforcers does not mean they cannot regulate their behavior. Rather, they can increase the effectiveness of delayed reinforcers by increasing the salience of their relationship with behavior, which otherwise might be ambiguous because of the temporal gap, through self-administration of informative intermediate stimuli. Therefore, alternative theoretical accounts that can integrate these data and guide future research along new directions are needed. Parameters of salience and temporal relationship between stimuli might thus become more relevant targets of study than focusing on personal characteristics associated with practices of "selfreward," opening up a range of new and potentially more effective selfmanagement interventions. REFERENCES Bandura, A. Self-reinforcement: Theoretical and methodological considerations. Behaviorism, 1976, 4, Bandura, A. In search of pure unidirectional determinants. Behavior Therapy, 1981, 12, 3O-4O. Bandura, A., & Kupers, C. J. Transmission of patterns of self-reinforcement through modeling. Journal of Abnormal and Social Psychology, 1964, 69, I-9. Bandura, A., & Perloff, B. Relative efficacy of self-monitored and externally imposed reinforcement systems. Journal of Personality and Social Psychology, 1967, 7, Castro, L., & Pereira, C. Auto-refuerzo: Revisi6n critica y reinterpretaci6n te6rica. Revista de Andlisis del Comportamiento, 1983, 1, i-28. Castro, L., & Rachlin, H. Self-reward, self-monitoring and self-punishment as feedback in weight control. Behavior Therapy, 1980, 11, Catania, A.C. The myth of self-reinforcement. Behaviorism, 1975, 3, Catania, A.C. Self-reinforcement revisited. Behaviorism, 1976, 4, Felixbrod, J. J., & O'Leary, K.D. Self-determination of academic standards by children: Toward freedom from external control. Journal of Educational Psychology, 1974, 66, Ferster, C. B., Nurnberg, J. I., & Levitt, E.B. The control of eating. Journal of Mathetics, 1962, 1, Fuchs, C. A., & Rehm, L. P. A self-control behavior therapy program for depression. Journal of Consulting and Clinical Psychology, 1977, 45, Gewirtz, J.L. The roles of overt responding and extrinsic reinforcement in "self" and "'vicarious reinforcement" phenomena in "observational learning" and imitation. In R. Giaser (Ed.), The nature of reinforcement, New York: Academic, 1971.

10 SELF-REINFORCEMENT AND WEIGHT CONTROL 681 Goldiamond, I. Fables, armady~ics and self-reinforcement. Journal of Applied Behavior Analysis, 1976, 9, (a) Goldiamond, I. Self-reinforcement. Journal of Applied Behavior Analysis, 1976, 9, (b) Kanfer, F. H., Bradley, M. M., & Marston, A. R. Self-reinforcement as a function of degree of learning. Psychological Reports, 1%2, 10, Kanfer, F. H., & Duerfeldt, P. H. Comparison of self-reward and self-criticism as a function of types of prior external reinforcement. Journal of Personality and Social Psychology, 1%8, 8, Kanfer, F. H., & Karoly, P. Self-control: A behavioristic excursion into the lion's den. Behavior Therapy, 1972, 3, Mahoney, M.J. Self-reward and self-monitoring techniques for weight control. Behavior Therapy, 1974, 5, Mahoney, M.J. Terminal terminology: A self-regulated response to Goldiamond. Journal of Applied Behavior Analysis, 1976, 9, Mahoney, M. J., & Bandura, A. Self-reinforcement in pigeons. Learning and Motivation, 1972, 3, Premack, D. Reinforcement theory. In D. Levine (Ed.), Nebraska Symposium on Motivation. Lincoln: University of Nebraska Press, 1%5. Premack, D. Catching-up with common sense or two sides of generalization: Reinforcement and punishment. In R. Glaser (Ed.), The nature of reinforcement. New York: Academic, Rachlin, H. Self-control. Behaviorism, 1974, 2, Rachlin, H. Behavior and learning. San Francisco: Freeman, Staddon, J. E.R. Operant behavior as adaptation to constraint. Journal of Experimental Psychology: General, 1979, 105, Stuart, R.B. Situational versus self-control. In, R. H. Rubin, J. D. Henderson, H. Fensterheim, & L. P. Ullmann (Eds.), Advances in behavior therapy. New York: Academic, Stuart, R. B., & Davis, B. Slim chance in a fat worm. Champaign, IL.: Research Press, Thoresen, C. E., & Mahoney, M.J. Behavioral self-control. New York: Holt, Thoresen, C. E., & Wilbur, C.S. Some encouraging thoughts about self-reinforcement. Journal of Applied Behavior Analysis, 1976, 9, Timberlake, W., & Allison, J. Response deprivation: An empirical approach to instrumental performance. Psychological Review, 1974, 81, Torgersson, W.S. Theory and methods of scaling. New York: Wiley, RECEIVED: December 20, 1982 FINAL ACCEPTANCE: March 17, 1983