Self-control deficits and eating problems: A reexamination

Self-control Deficits and Eating Problems: A Reexamination

Rhiannon Jones, M. Phil. Robert J. Edelmann, Ph.D.

(Accepted 15 July 1988)

It has been suggested that self-control deficits play a part in the etiology of eating disorders. The issue is complicated, however, by the links between eating problems, self-contra/ deficits, and depression. The present study was an experimental investigation of self-control deficits in a sample of college females with elevated €01 scores who were screened for depression. Whereas the results support the ex- istence of some self-control deficits, there was a failure to support others. Although there are possible methodological explanations for the results, the need to assess the relative contribution of mood and cognition to self-control deficits associated with eating problems is stressed.

The part played by maladaptive cognitions in the maintenance of eating problems has been emphasized by a number of authors (e.g., Fairburn, 1985; Gar- ner & Bemis, 1982). Such distorted cognitions include the assumption that weight, shape, or thinness can serve as the solelprominent basis for inferring personal value or self-worth; the assumption that complete self-control is necessary or even desirable; the assumption that absolute certainty is necessary in making decisions. As patients experience the pleasure of successful weight loss, their sense of mastery, self-control, and self-discipline serves to reinforce their condition, particularly since this occurs within the context of feelings of inadequacy in most other areas of functioning (Bemis, 1983; Garner & Bemis, 1982).

Self-control deficits in relation to eating disorders have been investigated in a number of studies. Weiss and Ebert (1983) found that bulimics scored significantly lower than controls in the belief that they had control over their lives. In a further study McClaughlin, Karp, and Herzog (1985) found that both their anorexic and bulimic groups displayed significantly more rigidity of

Rhiannon Jones, M. Phil., is a Clinical Psychologist, Ridgewood Centre, Frirnley. Robert J. Edelmann, Ph.D., is Lecturer in Clinical Psychology, Department of Psychology, University of Surrey. Address all correspondence to Robert 1. Edelrnann, Department of Psychology, University of Surrey, Curldford, Sur- rey, CU2 SXH, England.

lnternational journal of Eating Disorders, Vol. 8, No. 6, 695-699 ( 1 989) 0 1989 by John Wiley & Sons, Inc. CCC 0276-3478/89/06069545$04.00

696 Jones and Edelrnann

control than control subjects, although Heilbrun and Bloomfield (1986) found that females displaying bulimic tendencies were less capable of cognitive impulse control and more limited in their scanning of internal cues than controls. This pattern of results did not occur for women with anorexic tendencies.

The question of self-control and eating problems is complicated, however, by the links between self-control deficits and depression (Rehm, 1977) and between depression and anorexia (e.g., Rollins & Piazza, 1978) and bulimia (e.g., Williamson, Prather, Upton, Davis, Ruggiero, & Van Buren, 1987). Many of the self-control deficits evident in eating problems may be due to the depressive component of the disorder. The present study was thus a reexamination of issues raised by Heilbrun and Bloomfield (1986) concerning cognitive differences between women with and without a tendency toward eating problems. The theoreticaI self-control model for depression developed by Rehm (1977) was applied to a population prone to eating problems while screening out subjects with elevated depres’sion scores.

The salient features of Rehm’s model involve three processes of self-control, which regulate behavior: self-monitoring, self-evaluation, and self-reinforcement. In relation to eating problems the three components may reflect a lack of motivation for change, body image dissatisfaction (the setting of unrealistic achievement expectations), a desire for immediate reward, and erroneous attributions of hopelessness and inadequacy in situations in which the person is not responsible for outcome. The present study used an adaptation of an experimental task used by Wener and Rehm (1975) to assess issues of reinforcement preference, self-evaluative criteria, and attributions for causality in a population with a tendency toward eating problems. Specifically it was hy- pothesized that this group would (1) have a greater preference for small but immediate as opposed to larger but delayed reinforcement, (2) have more strin- gent self-evaluative criteria, (3) be differentially influenced by rate of reinforcement, (4) underestimate their actual performance, and (5) make excessively external attributions of causality in relation to a population without a tendency toward eating problems.

METHOD

Subjects

The initial sample consisted of 61 female subjects, drawn from aerobics classes, dance, and psychology courses, each of whom completed the Eating Disorders Inventory (EDI; Garner, Olmstead, & Polivy, 1983) and the Beck De- pr&nn Imentory (BDI; Beck, Ward, Mendelson, Nock, & Erbaugh 1961). The former scale has been shown to differentiate reliably between appropriate clinical and nonclinical populations, whereas the latter scale is a widely used clinical screening device with established reliability and validity.

Twenty-eight of the initial sample were excluded from the subsequent study: 10 owing to BDI scores > 10, 10 who could not be contacted, and 8 who re- fused to take part. The remaining 33 subjects had an average age of 23.4 years

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and ED1 scores which ranged from 3 to 92. For the subsequent study, subjects were divided around a median split of 29 into a low ED1 (LEDI) group and a high ED1 (HEDI) group.

Design and Procedure

A pseudosocial intelligence task and a procedure devised by Wener and Rehm (1975) was used. Stimuli, presented on a visual display unit, consisted of 35 stimulus words with 3 associated words beneath each. A row of three but- tons corresponding to the three associated words were immediately in front of the subject. The subject’s task was to decide which of the three words a group of students most frequently associated with the first word appearing on the screen. Subjects were assigned at random to one of two reinforcement sched- ules with the words “well done” appearing either 20% or 80% of the time after the subject’s response; criteria were selected on the basis of a study by Milech and Neasdale (1984). The differential effects of these reinforcement rates upon response latency was assessed for each subject. Stringency of subject’s self- evaluation criteria was evaluated by asking subjects to evaluate prior to completing the task their likely success rate. Preference for delayed versus immediate reinforcement was assessed by asking subjects “if given a choice of reward for taking part in this study would you take €10 now or delay one month and take €20?” After completing the task, self-perception of performance was assessed by asking subjects to estimate their accuracy. Attributions of accuracy were assessed by asking subjects to rate from 0 to 100 the extent to which performance outcome was due to ability, effort, luck, personal factors, and situational factors.

RESULTS

The results will be presented in the order of the hypotheses given earlier.

1. Preference for smaller but immediate as opposed to larger but delayed reinforcement. Almost all subjects in both HEDI and LEDI opted for the latter reward.

2. Stringency of subject’s self-evaluative criteria. Although the HEDI group gave a slightly lower estimate of their likely success rate than the LEDI group, the difference was not significant (HEDI, X = 55.6, SD = 17.1; LEDI, X = 60.6, SD = 15.3; figures represent percentage estimated likely success rate).

Each of the following variables was analyzed with a two-way ANOVA, the between-subjects’ variable being group (HEDI versus LEDI), while the within- subjects’ variable was reinforcement rate (80% versus 20%).

3. Differential effects of reinforcement rates. Although there was a significant ef- fect of reinforcement schedule upon response time (20%, X = 6.47; 8096, X = 4.72; F = 4.99, p < .05), there was very little difference in response rate between the HEDI and LEDI groups.

4. Self-preception of performance. Although the HEDI group gave a lower esti-

698 Jones and Edelrnann

mate of their perceived performance outcome than the LEDI group, the difference was not significant (HEDI X = 48.5; LEDI X = 60, figures represent percentage perceived success rate).

a. Ability. LEDI subjects were more likely than HEDI subjects to attribute outcome to their own ability (HEDI, X = 36; LEDI, X = 58; df 1, 29; F = 5.73; p < .05).

b. Effort. HEDI subjects assigned to the high-reinforcement schedule were more likely than LEDI subjects to attribute their performance to effort; the converse was true for subjects assigned to the low-reinforcement schedule (group X reinforcement rate interaction: HEDI, 80% X = 47.8; HEDI, 20% X = 37.5; LEDI, 80% X = 32.5; LEDI, 20% X = 58.7; df 1, 29; F = 4.19; p < .05). There were no significant main effects or interactions for attributions O f

5. Attributions of causality:

c. Luck, or d. Personal factors. e. Situational factors. HEDI subjects assigned to the high-reinforcement

schedule were more likely that LEDI subjects to attribute their performance to situational factors; the converse was true for subjects assigned to the low-reinforcement schedule (group X reinforcement rate interaction: HEDI, 80% X = 20.6; HEDI, 20% X = 8.1; LEDI, 80% X = 4.4; LEDI, 20% X = 10.0; df 1, 29; F = 3.2; p < .05).

DISC U SSlON

Results from the present study are mixed. There was a failure to support some self-control deficits: although results were in the predicted direction, HEDI subjects did not show evidence of significantly stricter self-evaluative criteria, nor were they differentially effected by reinforcement rates. This is con- trary to Bruch’s (1973) suggestion that anorexics set unrealistic performance standards and Heilbrun and Bloomfields (1986) finding that eating problems are related to poorer impulse control. Other self-control defecits, however, were supported: there was a tendency for HEDI scorers to be less likely to attribute their performance to ability and more likely to attribute good performance to effort and situational factors. With the exception of effort attributions, this tends to be in line with studies which have shown that people with eating problems are more influenced in their behavior and beliefs by external as opposed to internal factors (Garfinkel, 1981; Mclaughlin et al., 1985; Weiss & Ebert, 1983).

There are a number of possible explanations for the present results. First, given that the present study was based upon an unselected sample of college females assigned to an eating problem group by scores obtained on an eating questionnaire, the results may reflect a trend which would be enhanced in the appropriate clinical group. It should be noted, however, that Heilbrun and Bloomfield (1986) used a similar nonclinical population. Second, it is possible that a laboratory procedure involving a pseudointelligence test provides an in- appropriate assessment for the hypotheses under investigation. However, sim-

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ilar procedures have been used effectively by Rehm and colleagues for assessing self-control deficits relating to depression. Third, it is possible that many self-control deficits evident in eating disorders may be due to the depressive component of the disorder. The present results, while not providing clear evidence for this possibility, do raise a note of caution. As Strauss and Ryan (1988) point out, mood and cognition do not operate in isolation, and the relative contribution of each requires careful scrutiny.

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Garfinkel, P. E. (1981). Some recent observations on the pathogenesis of eating disorders. Canadian lournal of Psychiatry, 6 , 218-223.

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Self-control deficits and eating problems: A reexamination

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