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Imitation and locus of control
JOURNAL
OF
RESEARCH
IN
PERSONALITY
Imitation
and
STEVEN H. MCCOLLEY
9, 2 1I-2 16 (1975)
Locus
of Control
AND MARK
H. THELEN
University of Missouri at Columbia This study dealt with the relationship between Locus of Control and imitation. Based on a review of the social influence literature, it was hypothesized that external individuals would imitate equally under a condition of model-reward and a condition of no model-reward. It was further hypothesized that internal subjects would demonstrate more imitation under a condition of model-reward than under the condition of no model-reward. Male college students were classified as internal or external on the basis of their scores on the Locus of Control Scale. Internals imitated a rewarded model significantly more than a nonrewarded model. Externals imitated both models equaIly and at a rate comparable to internals who observed a rewarded model. Subject ratings of model competence were also positively related to imitation among internals but not among externals. The results are interpreted as offering support for the general notion of the effect of observer characteristics on imitation.
In his formulation of the imitative process, Bandura (1965, 1969) hypothesized that the performance of an imitative response is influenced by model-reward, while the acquisition of such a response is relatively independent of model-reward. In a recent review of the literature, Thelen and Rennie (1972) concluded that model-reward does not always increase the performance of imitative behavior. In a number of studies reviewed, there were no significant differences in imitation between subjects in model-reward and no model-reward conditions, while there were differences in other studies. Based on a review of the literature concerning personality variables and imitation, Akamatsu and Thelen (1974) suggested that personality variables of the observers may influence the amount of imitation following observation of a model in an ambiguous situation. Only a few researchers have attempted to investigate the relation between observer personality variables and model-reward effects on imitation. Gelfand (1962) found that manipulated failure experiences increased imitation of a successful peer model, but there were no such effects for rated self-esteem. These results are further limited in that all This research was conducted as part of the first author’s master’s thesis at the University of Missouri under the supervision of the second author. Requests for reprints should be sent to Mark H. Thelen, Department of Psychology, University of Missouri, Columbia, MO 65201. 211 Cowi& AII rights
@ 1975 by Academic Press. Inc. of reproduction in any form reserved.
212
MCCOLLEY
AND
THELEN
subjects were exposed to a successful model (model-reward manipulation). Epstein (1966) found that high authoritarian subjects imitated more than low authoritarian subjects, but again all subjects were exposed to a rewarded model. Heilbrun (1970) reported that college males who perceived their mothers as low on nurturance were more susceptible to the effects of both direct reward and model-reward than were subjects high on perceived nurturance. This study also lacked a control group for no model-reward, however. Thus, while there is some indication that observer characteristics influence the imitation process, there is no direct evidence of the relationship of observer characteristics to imitation under a condition of noconsequences to the model, nor the interaction of observer characteristics with model consequences. Locus of Control Of a number of personality variables, a personality variable which might be associated with imitation is the Locus of Control of Reinforcement (Rotter, 1966). This concept refers to the degree of control which an individual believes he exerts over his reinforcements. Rotter (1966) hypothesized that since the internal person felt he controlled his reinforcements, and preferred to do so, he would be resistive to perceived attempts to control or influence him. Externals, on the other hand, would expect and prefer such control and hence be more susceptible to influence attempts. A number of studies have found limited support for this hypothesis (Biondo & McDonald, 1971; Crowne & Liverant, 1963; Getter, 1962; Gore, 1962; Strickland, 1962). Taken on the whole, these studies show that the external individual is a conformist and highly susceptible to social influence attempts, while the internally oriented person does not conform as readily, nor is he so easily influenced. The internal does not appear to react negatively to such attempts, however, and may even yield if he perceives it to be to his advantage to do so and is able to do so in such a way as to maintain his control. No previous study has investigated the relationship between Locus of Control and imitation. The purpose of the present study was to investigate the relationship between performance of an imitative response in subjects with either an internal control orientation or external control orientation under conditions of model-reward or no model-reward. A condition of no model-reward would appear to be analogous to the more traditional conformity study in that there is no external gain offered for performing in a given way. Hence, it was predicted that externals would exhibit more spontaneous imitation with no model-reward than internals. A condition of model-reward, however, supplies the observer with additional information which reduces ambiguity and may indicate specific
IMITATION
AND
LOCUS
OF
CONTROL
213
responses for which reward is given. Considering that internals will conform when it is potentially advantageous to do so, it was predicted that internals with model-reward, should imitate more than internals with no model-reward. It follows from these predictions, that externals would exhibit no difference in imitation with the presence or absence of modelreward, and that no difference in imitation for internals and externals with model-reward would be observed. METHOD
Subjects One hundred thirty three male undergraduates were administered the Locus of Control Scale (Rotter, 1966). The mean and standard deviation for this sample were 10.22 and 4.6 1, respectively. The upper and lower thirds of the distribution were labeled as external (,? = 15.73, SD = 2.06, n = 26) and internal (x = 4.50, SD = 2.36, n = 26)) respectively. Half the subjects in each Locus of Control group were assigned to the no model-reward treatment and half to the model-reward treatment, yielding a cell n of 13.
Apparatus
and Task
A portable videotape playback unit was used to present the model to the subjects. The model’s behavior consisted of judging which of three lines on each of 34 stimulus cards appeared to be the longest. In actuality, most of the stimulus cards had lines of equal length, providing the subject with an ambiguous situation in which imitative behavior could be demonstrated.
Procedure Each subject was brought into the experimental setting individually. He was informed that he was participating in an experiment concerned with physiological responses of a person while he observed another person perform a task and while he performed the same task. Then the subject was connected to a pair of electrodes which he was informed led to a device for recording the Galvanic Skin Response. The electrodes were not actually recording any information. Once the subject was connected, his attention was directed to the TV monitor and he viewed the appropriate tape for his condition. All subjects were shown tapes of a model performing the same judgments on a series of 10 stimulus cards with three lines on each card. On 4 of these 10 trials, there was a discernable difference in the length of the lines, while on 6 trials the lines were of equal length. In the model-reward tape, the experimenter verbally rewarded (e.g., That’s good: That’s right) the model for his responses on 90% of the trials, leaving only one of the ambiguous trials not rewarded. In the no model-reward tape, the experimenter administered no reward to the model. In both conditions, the model always gave the correct response to the discriminably different stimuli. Following the observation session, all subjects observed an identical tape in which the model responded with his judgment of the longest tine on each of 24 stimulus cards. The subject was asked to make independent judgments and report them following the report of the model on each trial. No reward was given to either the model or subject during this portion of the experiment. Eight of the 24 stimulds cards presented had discriminably different lines, the remaining 16 being ambiguous. It was felt that the inclusion of such unambiguous stimuli would make the task appear more realistic and serve to reduce the effect of any sanctions against imitation which might be present in this population.
214
MCCOLLEY
AND THELEN
Following the performance period, subjects were asked to rate the performance of the other subject (actually the model) on the task, using a five-point scale. A rating of 1 was “very poor,” 3 was “fair,” and 5 was “very good.” Subjects were also presented with the following open-ended question: “Briefly describe what you think the purpose of the experiment was.” Written responses to this question were later used for assessment of the degree of awareness regarding the true purpose of the experiment. Subjects were then informed of the deception involved and the actual purpose of the experiment.
RESULTS
The dependent variable was the number of agreement responses by subject on each of 16 ambiguous trials. Data relating to the predictions is presented in Table 1. The Mann-Whitney U test was used to test the predictions (Siegel, 1956). All but the first of the predictions were supported. Internally oriented subjects imitated significantly more under the model-reward condition than the no model-reward condition, while there was no difference for external subjects under the same two conditions. The prediction of no differences for the internals and externals under model-reward was supported, but the prediction of greater imitation by externals under conditions of no model-reward was not supported. In analyzing the ratings of model competence, no ratings of 1 (low perceived competence) were obtained. Hence, ratings of 2 and 3 were combined to form a moderate perceived competence group, and ratings of 4 and 5 were combined to form a high perceived competence group. Because it would appear that model-reward should influence the observer’s perception of the competency of the model, it was felt that the ratings should accurately reflect the effect of the manipulation. The Mann-Whitney U test was again used to compare imitation scores of internals and externals with high and low ratings of perceived model competence (Table 2). This analysis yields further support for the predictions. More specifically, while there was no difference for internals and externals who rated the model high in competence, externals imitated the model perceived as low in competence more than did internals TABLE MEDIAN
NUMBER
No model-reward
1
OF IMITATIVE
RESPONSES
Model-reward
Probability level (one-tailed)
Internal Locus of Control
5.125
6.417
.025
External Locus of Control
5.688
6.875
n.s.
Probability level (one-tailed)
n.s.
n.s.
IMITATION
AND
215
LOCUS OF CONTROL
TABLE 2 MEDIAN NUMBER OF IMITATIVE RESWNSES AS A FUNCTION OF F%R~E~vED MODH. COMPETENCE Perceived model competence Probability level (one-tailed)
Moderate
High
Internal Locus of Control
5.583 n = I5
6.875 ?I=11
.025
External Locus of Control
6.500 n = 16
6.500 tl= 10
n.s.
Probability level (one-tailed)
.06
n.s.
( p = .06). Similarly, while the externals imitated ,models of both competence levels equally, the internals imitated the model perceived as highly competent significantly more than the one rated as low in competence (p = .025).
Based on the written responses to the question concerning the purpose of the experiment, subjects were classified as either Aware or Unaware of the true purpose of the experiment. Two judges independently rated each subject as Aware or Unaware. The judges disagreed on the classification of only 2 of the 52 subjects (r = .%). Disagreements were resolved by discussion. While there were no overall differences in imitation between Aware (n = 31) and Unaware (n = 21) subjects (z = 0.134)) the internal subjects who were Aware in the model-reward condition (n = 8) imitated significantly more than the Aware internals in the no model-reward condition (n = 8; z = 2.70; p = .007, two-tailed). There were no differences in imitation for Aware (n = 15) and Unaware (n = 11) externals. This supports the notion that internals will yield to social influence when it is perceived to be possibly advantageous to do so (Crowne & Liverant, 1963). DISCUSSION The results show that subjects of different control orientations differentially imitated a model perceived as only moderate in competence (the externals imitating more than the internals), but imitated equally a model perceived as high in competence. This indicates that imitation was influenced by both the observer’s perception of the model’s competence and Locus of Control orientation of the observer. It is possible that the above results stemmed from a differential influence of Locus of Control on perceived model competence. However a 2 X 2 &i-square
216
MCCOLLEY
AND
THELEN
analysis showed that perceived model competence was unrelated to locus of control (X2 = .07). While the present study shows that one observer characteristic (Locus of Control) affects imitation, it seems reasonable that other observer characteristics may Sect imitation. Further research on the relationship of such variables to imitation would seem to be useful in accounting for some of the within-treatment variance often found in imitation studies (Akamatsu & Thelen, 1974). Consideration of such variables in future studies may also serve to resolve some of the differences in results on the effects of model-reward on imitation (Thelen & Rennie, 1972). Akamatsu and Thelen (1974) also hypothesize that observer characteristics have the greatest effect in an ambiguous or unstructured situation, while their impact may be overshadowed by variables which create a more structured situation. Considering that high perceived model competence affords less ambiguity and more information than lower perceived model competence, the results of the present study support such a formulation. Differences between internals and externals were apparent only under conditions of relatively low perceived model competence. REFERENCES Akamatsu, T. J., & Thelen, M. H. A review of the literature on observer characteristics and imitation. Developmental Psychology, 1974, 10, 3 8-48. Bandura, A. Vicarious processes: A case of no-trial learning. In L. Berkowitz (Ed.), Advances in experimental socialpsychology. New York: Academic Press, 1965. Vol. 2. Bandura, A. Social learning theory of identificatory processes. In D. A. Goslin (Ed.), Handbook of socialization theory and research. Chicago: Rand-McNally, 1969. Biondo, J., & MacDonald, A. P. Locus of control and social influence. Journal of Personality, 197 1, 39, 407-4 19. Crowne, D. P., & Liverant, S. Conformity under varying conditions of personal commitment. Journal of Abnormal and Social Psychology, 1963,66, 547-555. Epstein, K. Aggression toward outgroups as a function of authoritarianism and imitation of aggressive models. Journal of Personality and Social Psychology, 1966, 3, 547-549. Gelfand, D. The influence of self-esteem on rate of verbal conditioning and social matching behavior. Journal of Abnormal and Social Psychology, 1962, 65, 259-265. Getter, H. Variables affecting the value of the reinforcement in verbal conditioning. Unpublished doctoral dissertation, Ohio State University, 1962. Gore, P. M. Individual differences in the effects of experimenter bias. Unpublished doctoral dissertation, Ohio State University, 1962. Heilbrun, A. B., Jr. Perceived maternal child rearing experiences and the effects of vicarious and direct reinforcement on males. Child Development, 1970, 41, 253-261. Rotter, J. B. Generalized expectancies for internal versus external control of reinforcement. Psychological Monographs, 1966, 80 (l), l-25. Strickland, B. R. Individual differences in verbal conditioning extinction and awareness. Journal of Personality, 1970, 38, 364-378. Thelen, M. H., & Rennie, D. L. The effect of vicarious reinforcement on imitation: a review of the literature. In B. A. Maher (Ed.), Progress in experimental personality research. New York: Academic Press, 1972. Siegel, S. Nonparamettic statistics for the behavioral sciences. New York: McGraw-Hill, 1956.
OF
RESEARCH
IN
PERSONALITY
Imitation
and
STEVEN H. MCCOLLEY
9, 2 1I-2 16 (1975)
Locus
of Control
AND MARK
H. THELEN
University of Missouri at Columbia This study dealt with the relationship between Locus of Control and imitation. Based on a review of the social influence literature, it was hypothesized that external individuals would imitate equally under a condition of model-reward and a condition of no model-reward. It was further hypothesized that internal subjects would demonstrate more imitation under a condition of model-reward than under the condition of no model-reward. Male college students were classified as internal or external on the basis of their scores on the Locus of Control Scale. Internals imitated a rewarded model significantly more than a nonrewarded model. Externals imitated both models equaIly and at a rate comparable to internals who observed a rewarded model. Subject ratings of model competence were also positively related to imitation among internals but not among externals. The results are interpreted as offering support for the general notion of the effect of observer characteristics on imitation.
In his formulation of the imitative process, Bandura (1965, 1969) hypothesized that the performance of an imitative response is influenced by model-reward, while the acquisition of such a response is relatively independent of model-reward. In a recent review of the literature, Thelen and Rennie (1972) concluded that model-reward does not always increase the performance of imitative behavior. In a number of studies reviewed, there were no significant differences in imitation between subjects in model-reward and no model-reward conditions, while there were differences in other studies. Based on a review of the literature concerning personality variables and imitation, Akamatsu and Thelen (1974) suggested that personality variables of the observers may influence the amount of imitation following observation of a model in an ambiguous situation. Only a few researchers have attempted to investigate the relation between observer personality variables and model-reward effects on imitation. Gelfand (1962) found that manipulated failure experiences increased imitation of a successful peer model, but there were no such effects for rated self-esteem. These results are further limited in that all This research was conducted as part of the first author’s master’s thesis at the University of Missouri under the supervision of the second author. Requests for reprints should be sent to Mark H. Thelen, Department of Psychology, University of Missouri, Columbia, MO 65201. 211 Cowi& AII rights
@ 1975 by Academic Press. Inc. of reproduction in any form reserved.
212
MCCOLLEY
AND
THELEN
subjects were exposed to a successful model (model-reward manipulation). Epstein (1966) found that high authoritarian subjects imitated more than low authoritarian subjects, but again all subjects were exposed to a rewarded model. Heilbrun (1970) reported that college males who perceived their mothers as low on nurturance were more susceptible to the effects of both direct reward and model-reward than were subjects high on perceived nurturance. This study also lacked a control group for no model-reward, however. Thus, while there is some indication that observer characteristics influence the imitation process, there is no direct evidence of the relationship of observer characteristics to imitation under a condition of noconsequences to the model, nor the interaction of observer characteristics with model consequences. Locus of Control Of a number of personality variables, a personality variable which might be associated with imitation is the Locus of Control of Reinforcement (Rotter, 1966). This concept refers to the degree of control which an individual believes he exerts over his reinforcements. Rotter (1966) hypothesized that since the internal person felt he controlled his reinforcements, and preferred to do so, he would be resistive to perceived attempts to control or influence him. Externals, on the other hand, would expect and prefer such control and hence be more susceptible to influence attempts. A number of studies have found limited support for this hypothesis (Biondo & McDonald, 1971; Crowne & Liverant, 1963; Getter, 1962; Gore, 1962; Strickland, 1962). Taken on the whole, these studies show that the external individual is a conformist and highly susceptible to social influence attempts, while the internally oriented person does not conform as readily, nor is he so easily influenced. The internal does not appear to react negatively to such attempts, however, and may even yield if he perceives it to be to his advantage to do so and is able to do so in such a way as to maintain his control. No previous study has investigated the relationship between Locus of Control and imitation. The purpose of the present study was to investigate the relationship between performance of an imitative response in subjects with either an internal control orientation or external control orientation under conditions of model-reward or no model-reward. A condition of no model-reward would appear to be analogous to the more traditional conformity study in that there is no external gain offered for performing in a given way. Hence, it was predicted that externals would exhibit more spontaneous imitation with no model-reward than internals. A condition of model-reward, however, supplies the observer with additional information which reduces ambiguity and may indicate specific
IMITATION
AND
LOCUS
OF
CONTROL
213
responses for which reward is given. Considering that internals will conform when it is potentially advantageous to do so, it was predicted that internals with model-reward, should imitate more than internals with no model-reward. It follows from these predictions, that externals would exhibit no difference in imitation with the presence or absence of modelreward, and that no difference in imitation for internals and externals with model-reward would be observed. METHOD
Subjects One hundred thirty three male undergraduates were administered the Locus of Control Scale (Rotter, 1966). The mean and standard deviation for this sample were 10.22 and 4.6 1, respectively. The upper and lower thirds of the distribution were labeled as external (,? = 15.73, SD = 2.06, n = 26) and internal (x = 4.50, SD = 2.36, n = 26)) respectively. Half the subjects in each Locus of Control group were assigned to the no model-reward treatment and half to the model-reward treatment, yielding a cell n of 13.
Apparatus
and Task
A portable videotape playback unit was used to present the model to the subjects. The model’s behavior consisted of judging which of three lines on each of 34 stimulus cards appeared to be the longest. In actuality, most of the stimulus cards had lines of equal length, providing the subject with an ambiguous situation in which imitative behavior could be demonstrated.
Procedure Each subject was brought into the experimental setting individually. He was informed that he was participating in an experiment concerned with physiological responses of a person while he observed another person perform a task and while he performed the same task. Then the subject was connected to a pair of electrodes which he was informed led to a device for recording the Galvanic Skin Response. The electrodes were not actually recording any information. Once the subject was connected, his attention was directed to the TV monitor and he viewed the appropriate tape for his condition. All subjects were shown tapes of a model performing the same judgments on a series of 10 stimulus cards with three lines on each card. On 4 of these 10 trials, there was a discernable difference in the length of the lines, while on 6 trials the lines were of equal length. In the model-reward tape, the experimenter verbally rewarded (e.g., That’s good: That’s right) the model for his responses on 90% of the trials, leaving only one of the ambiguous trials not rewarded. In the no model-reward tape, the experimenter administered no reward to the model. In both conditions, the model always gave the correct response to the discriminably different stimuli. Following the observation session, all subjects observed an identical tape in which the model responded with his judgment of the longest tine on each of 24 stimulus cards. The subject was asked to make independent judgments and report them following the report of the model on each trial. No reward was given to either the model or subject during this portion of the experiment. Eight of the 24 stimulds cards presented had discriminably different lines, the remaining 16 being ambiguous. It was felt that the inclusion of such unambiguous stimuli would make the task appear more realistic and serve to reduce the effect of any sanctions against imitation which might be present in this population.
214
MCCOLLEY
AND THELEN
Following the performance period, subjects were asked to rate the performance of the other subject (actually the model) on the task, using a five-point scale. A rating of 1 was “very poor,” 3 was “fair,” and 5 was “very good.” Subjects were also presented with the following open-ended question: “Briefly describe what you think the purpose of the experiment was.” Written responses to this question were later used for assessment of the degree of awareness regarding the true purpose of the experiment. Subjects were then informed of the deception involved and the actual purpose of the experiment.
RESULTS
The dependent variable was the number of agreement responses by subject on each of 16 ambiguous trials. Data relating to the predictions is presented in Table 1. The Mann-Whitney U test was used to test the predictions (Siegel, 1956). All but the first of the predictions were supported. Internally oriented subjects imitated significantly more under the model-reward condition than the no model-reward condition, while there was no difference for external subjects under the same two conditions. The prediction of no differences for the internals and externals under model-reward was supported, but the prediction of greater imitation by externals under conditions of no model-reward was not supported. In analyzing the ratings of model competence, no ratings of 1 (low perceived competence) were obtained. Hence, ratings of 2 and 3 were combined to form a moderate perceived competence group, and ratings of 4 and 5 were combined to form a high perceived competence group. Because it would appear that model-reward should influence the observer’s perception of the competency of the model, it was felt that the ratings should accurately reflect the effect of the manipulation. The Mann-Whitney U test was again used to compare imitation scores of internals and externals with high and low ratings of perceived model competence (Table 2). This analysis yields further support for the predictions. More specifically, while there was no difference for internals and externals who rated the model high in competence, externals imitated the model perceived as low in competence more than did internals TABLE MEDIAN
NUMBER
No model-reward
1
OF IMITATIVE
RESPONSES
Model-reward
Probability level (one-tailed)
Internal Locus of Control
5.125
6.417
.025
External Locus of Control
5.688
6.875
n.s.
Probability level (one-tailed)
n.s.
n.s.
IMITATION
AND
215
LOCUS OF CONTROL
TABLE 2 MEDIAN NUMBER OF IMITATIVE RESWNSES AS A FUNCTION OF F%R~E~vED MODH. COMPETENCE Perceived model competence Probability level (one-tailed)
Moderate
High
Internal Locus of Control
5.583 n = I5
6.875 ?I=11
.025
External Locus of Control
6.500 n = 16
6.500 tl= 10
n.s.
Probability level (one-tailed)
.06
n.s.
( p = .06). Similarly, while the externals imitated ,models of both competence levels equally, the internals imitated the model perceived as highly competent significantly more than the one rated as low in competence (p = .025).
Based on the written responses to the question concerning the purpose of the experiment, subjects were classified as either Aware or Unaware of the true purpose of the experiment. Two judges independently rated each subject as Aware or Unaware. The judges disagreed on the classification of only 2 of the 52 subjects (r = .%). Disagreements were resolved by discussion. While there were no overall differences in imitation between Aware (n = 31) and Unaware (n = 21) subjects (z = 0.134)) the internal subjects who were Aware in the model-reward condition (n = 8) imitated significantly more than the Aware internals in the no model-reward condition (n = 8; z = 2.70; p = .007, two-tailed). There were no differences in imitation for Aware (n = 15) and Unaware (n = 11) externals. This supports the notion that internals will yield to social influence when it is perceived to be possibly advantageous to do so (Crowne & Liverant, 1963). DISCUSSION The results show that subjects of different control orientations differentially imitated a model perceived as only moderate in competence (the externals imitating more than the internals), but imitated equally a model perceived as high in competence. This indicates that imitation was influenced by both the observer’s perception of the model’s competence and Locus of Control orientation of the observer. It is possible that the above results stemmed from a differential influence of Locus of Control on perceived model competence. However a 2 X 2 &i-square
216
MCCOLLEY
AND
THELEN
analysis showed that perceived model competence was unrelated to locus of control (X2 = .07). While the present study shows that one observer characteristic (Locus of Control) affects imitation, it seems reasonable that other observer characteristics may Sect imitation. Further research on the relationship of such variables to imitation would seem to be useful in accounting for some of the within-treatment variance often found in imitation studies (Akamatsu & Thelen, 1974). Consideration of such variables in future studies may also serve to resolve some of the differences in results on the effects of model-reward on imitation (Thelen & Rennie, 1972). Akamatsu and Thelen (1974) also hypothesize that observer characteristics have the greatest effect in an ambiguous or unstructured situation, while their impact may be overshadowed by variables which create a more structured situation. Considering that high perceived model competence affords less ambiguity and more information than lower perceived model competence, the results of the present study support such a formulation. Differences between internals and externals were apparent only under conditions of relatively low perceived model competence. REFERENCES Akamatsu, T. J., & Thelen, M. H. A review of the literature on observer characteristics and imitation. Developmental Psychology, 1974, 10, 3 8-48. Bandura, A. Vicarious processes: A case of no-trial learning. In L. Berkowitz (Ed.), Advances in experimental socialpsychology. New York: Academic Press, 1965. Vol. 2. Bandura, A. Social learning theory of identificatory processes. In D. A. Goslin (Ed.), Handbook of socialization theory and research. Chicago: Rand-McNally, 1969. Biondo, J., & MacDonald, A. P. Locus of control and social influence. Journal of Personality, 197 1, 39, 407-4 19. Crowne, D. P., & Liverant, S. Conformity under varying conditions of personal commitment. Journal of Abnormal and Social Psychology, 1963,66, 547-555. Epstein, K. Aggression toward outgroups as a function of authoritarianism and imitation of aggressive models. Journal of Personality and Social Psychology, 1966, 3, 547-549. Gelfand, D. The influence of self-esteem on rate of verbal conditioning and social matching behavior. Journal of Abnormal and Social Psychology, 1962, 65, 259-265. Getter, H. Variables affecting the value of the reinforcement in verbal conditioning. Unpublished doctoral dissertation, Ohio State University, 1962. Gore, P. M. Individual differences in the effects of experimenter bias. Unpublished doctoral dissertation, Ohio State University, 1962. Heilbrun, A. B., Jr. Perceived maternal child rearing experiences and the effects of vicarious and direct reinforcement on males. Child Development, 1970, 41, 253-261. Rotter, J. B. Generalized expectancies for internal versus external control of reinforcement. Psychological Monographs, 1966, 80 (l), l-25. Strickland, B. R. Individual differences in verbal conditioning extinction and awareness. Journal of Personality, 1970, 38, 364-378. Thelen, M. H., & Rennie, D. L. The effect of vicarious reinforcement on imitation: a review of the literature. In B. A. Maher (Ed.), Progress in experimental personality research. New York: Academic Press, 1972. Siegel, S. Nonparamettic statistics for the behavioral sciences. New York: McGraw-Hill, 1956.