Emotional arousal, isolation, and discrimination learning in children

JOURNAL

OF EXPERIMENTAL

Emotional

CHILD

PSYCHOLOGY

Arousal,

Isolation,

Learning RICHARD Depwrtment

H.

of Psychology,

1,

163-173

(1964)

and

Discrimination

in Children1

WALTERS

AND

Gnitlersity

Ross D. of Waterloo,

PARKE Ontario,

Canada

The social-drive hypothesis states that social deprivation arouses a social drive that motivates behavior “for” social reinforcers. An alternative explanation is that social deprivation can be an emotionally arousing stimulus and that faster learning by children following isolation reflects the arousal of a nonspecific drive condition. Eighty Grade IV children, 40 boys and 40 girls, learned a simple discrimination task following one of four manipulations: high arousal with isolation; high arousal without isolation; low arousal with isolation; and low arousal without isolation. Half the Ss under each manipulation were rewarded with verbal approval; the remainder received material rewards. Results indicated that the only important influence on learning was Ss’ level of arousal.

Gewirtz and Baer (1958a,b) reported that children who had experienced a 20-minute period of social isolation conditioned more readily in a simple discrimination-learning task, when verbal approval was used as a reinforcer, than did children who had not been isolated. They attributed their findings to the arousal by isolation of a social drive which motivated behavior irfor” a social reinforcer. Walters and Karal (1960) criticized this interpretation on the grounds that the isolation procedure may have aroused “anxiety” in young children and that the findings could therefore be interpreted without the postulation of a social drive? This latter interpretation is consonant with evidence from a variety of studies showing that moderate arousal or moderately heightened drive improves performance in some kinds of learning task (Bindra, 1959; Malmo, 1959). ‘This study was supported by a Public Health grant (605/S/293) of the (Canadian) National Health Grants Programme. It was made possible through the cooperation of the York Township Board of Education and the principals and staff of Keelesdale and Humbercrest Schools. The assistance in this project of Valerie A. Cane, Jeanette Cochrune, Bcttp Lou Jognt, and Susan J. Parke is gratefully acknowledged. ‘In earlier studies by the senior author and his collaborators (e.g., Walters and Karal, 1960), the term “anxiety” was utilized to drnote an emotional response to a specific threat situation. Theoretical considerations, outlined by Walters and Parke (1964). led to the substitution of the term “arousal” in this and other more recent publications (e.g., McNulty and Walters, 1962). 163

164

WALTERS

AND

PARKE

Walters and Ray (1960) repeated the conditioning procedures of Gewirtz and Baer by using a 2 X 2 design in which both degree of social contact and “anxiety” level were experimentally manipulated. In this study it was assumed that the placing of Grade 1 and Grade 2 children in a strange environment by a strange adult would be a stimulus for anxiety and that this anxiety would be reduced by the use of a familiar adult as E’s assistant. It was assumed also that a 20-minute period of isolation would, in itself, have little influence on responsiveness to social reinforcers. The results indicated that the “anxiety” variable was far more effective than the variable of isolation-interaction in facilitating conditioning. However, Walters and Ray failed to provide any validating measure of the effectiveness of their manipulation for inducing arousal in young children. Moreover, during the conditioning procedure they employed only social reinforcement of precisely the same kind as that used by Gewirtz and Baer. Since it is crucial to the social-drive hypothesis that this drive increases motivation for social reinforcers, the effects of varying the degree of social responsiveness of the experimenter during testing should perhaps also have been investigated. This paper reports a partial replication of the Walters and Ray study in which a physiological index of emotional arousal was secured and both verbal approval and impersonally dispensed material rewards were used as reinforcers. Children older than those used by Walters and Ray were selected as subjects partly to facilitate the use of a physiological index, and partly to increase the range of subjects with whom the phenomenon under investigation might. be demonstrated. The simple discrimination task utilized by Walters and Ray is unsuitable for older children; consequently, a task devised by Miller and Estes (1961) was substituted. The choice of a physiological index was limited by the necessity of carrying out the study within a school setting. Since there is some evidence that a fall in finger temperature is a concomitant of emotional arousal (Mittelman and Wolff, 1953, Mandler, Mandler, Kremen, and Sholiton, 1961) and equipment for recording this index is battery-operated and easily portable, the finger temperatures of S’s were recorded at the same time as the children carried out a discrimination-learning task. METHOD

Subjects Subjects were 40 Grade 4 boys and 40 Grade 4 girls from two schools in a single area of metropolitan Toronto. Five girls and five boys were

EMOTIONAL

randomly factorial isolation,

AROUSAL,

ISOLATION,

AND

DISCRIMINATION

165

assigned to each of eight conditions in a 2 X 2 X 2 X 2 design involving high versus low arousal, isolation versus no material versus verbal rewards, and sex of Ss. Apparatus

A 35 mm slide viewer was attached to a box containing a transformer, which operated the viewer light. When E pushed a button at the rear of the box, a slide was illuminated. When S pressed either of two buttons on the front of the box, the viewer light was extinguished; at the same time, one of two red lights on E’s side of the panel was illuminated, thus indicating to E which button S had pushed. The stimuli presented to S consisted of line drawings of a pair of faces which were identical except that the eyebrows on one face were drawn close to the eyes, whereas they were high up over the eyes on the other face. Four slides were used, two with the high-eyebrow face on the right and two with the high-eyebrow face on the left. Two pairs of slides were used in order to facilitate presentation. A Yellow Springs battery-operated telethermometer with thermistor probe was used to record S’s finger temperatures during testing. The thermistor probe was tightly secured with adhesive tape to the second finger of S’s left, hand, which was placed on a table with the probe upwards. Ss were instructed to keep the hand as still as possible through the testing period. The dial of the telethermometer permitted readings accurate to the nearest half degree; these were read by inspection and recorded on a data sheet. Procedure High-arousal, isolation condition: A female psychology student (E,) appeared at the door of the classroom and asked for S. The E instructed S to come with her without offering any explanation of her intentions. No conversation was initiated and any questions were answered in a brief and formal manner. The S was then taken to an unfamiliar room, seated in a chair facing the wall, and told: “I have something for you to do, but the machine is broken. Sit in this chair and do not move until I come back.” The E then left the room, Ten minutes lat’er she returned with the second E (E?), and seated S in front of the slide-viewer cabinet which until then had been concealed from S. The E taped a thermistor probe to S’s middle finger, again without explanation of what she was doing, and instructed S to keep his finger in one position on the table. Both Es then left the room. The S was left alone for 3 minutes to allow the finger temperature to stabilize. The Es then returned and commenced the conditioning procedure. E, recorded S’s finger temperature

166

WALTERS

AND

PARKE

while E,, with whom S had had least contact, supervised the learning task and dispensed the reinforcers. High-arousal, no-isolation condition: The procedure was identical with that used for high-arousal, isolation Ss, except that the lo-minute isolation period was omitted. While the finger temperature stabilized, both Es remained in the room. In order to maintain the presumably stressful atmosphere, their responses to S’s questions consisted only of the statement, “Just keep still and wait for a while,” and brief sentences and phrases of equivalent meaning. The Ss in the no-isolation groups were tested after mid-morning or noon-hour breaks, during which they had been interacting in play sittings with classmates for a period of at least 10 minutes. Low-aroma& isola,tion condition: While E fetched S from the classroom, she maintained a very pleasant and friendly manner. She explained to S that he was going to play a game and kept up a running conversation with him in an effort to make S feel at ease. The S was taken to the experimental room, where E said, ?Ve want to play a game with you, but it is broken right now. I do not want you to miss your turn, so just wait in t,his room while we fix it. We’ll come for you when the game is ready.” After 10 minutes, Es returned, and the thermistor probe was attached to S’s finger. It was explained to S that this would not hurt and that it was just the same as having a thermometer placed in his mouth, except that it would be placed on his finger. The Es then left the room for 3 minutes while the temperature stabilized. Low-arousal, no isolation condition: Ss were treated in the same manner as in the previous condition, except that the isolation period was omitted and consequently no explanation of a delay was needed. Conditioning procedure: All Ss were given the following instructions: ‘We are going to show you pictures of two twins, Bob and Bill, in this viewer in front of you, and WC want you to try to tell them apart. When the light comes on and you see the two twins, push the button underneath the twin you want to call Bill. You may choose either one the first time. After that, each time you see the twins try to pick that same one which you first called Bill.” Following these instructions, the slides were shown one at a time with the position of the twins varied according to a predetermined, randomly arranged schedule. Stimuli were presented and Ss’ responses recorded by Ez while finger temperat.ure readings were taken every 15 seconds by E,. The slides were presented for 80 trials or until S had made eight con.secutive correct responses.

EMOTIONAL

AROUSAL,

ISOLATION,

AND

DISCRIMINATION

167

Rewards Half the children in each arousal condition were reinforced with verbal approval, while half were given material rewards. Verbal reinforcement consisted in E’s saying, “That’s good,” “That’s right,” or “That’s fine,” following every correct response which S gave. The Ss in the material-reward condit,ion had every correct response reinforced with tokens, which were exchangeable for toys. After the learning instructions, these Ss were told: “Each time you push the right button, that is, the one that is under Bill, you will receive one of these little green disks. If you make enough right choices and collect’ enough green tokens, we shall give you a prize.” The s’s were then shown a tray of the toys that they could win, and the learning task was begun. VVhenever S made a correct response, E, who was concealed from S’s view by a screen, pushed a token through an aperture, from which it fell into a tray that had been set in front of S. The E made no comment of any kind during the dispensing of these reinforcers. At the end of t’he game, S was given a disk and told that in about a week’s time he could exchange it for a toy. The S was then taken back to his classroom. RESULTS

Table 1 presents means and Sljs of trials to criterion of boys and girls under each of the eight experimental conditions. The table also includes parallel results in terms of number of errors. The two measures are, of course, not entirely independent. A 2 X 2 X 2 X 2 analysis of variance of trials to criterion yielded a significant main effect for arousal level (F = 7.20; ?, < 0.01 for 1 and 64 df). The effects of isolation, sex of subject, and type of reward, and all interactions were nonsignificant. An analysis of variance of number of errors produced a similar result (F = 7.80 for arousal, no other significant effect). Because of the variability of room temperature and humidity, fingertemperature recordings were not entirely satisfactory. Moreover, readings from the dial of the telethermomet,er can only be gross when made by inspection. However, the selected criterion of arousal was the direction of change in temperature during the testing period, which could be adequately assessedfrom the data secured by E,. Table 2 gives the number of s’s who showed drops in finger temperature during the learning task. Data are based only on the first 2 minutes of learning, since some Ss had reached the criterion of learning by the end of this period and consequently the recording of their finger temperatures was dis-

168

WALTERS

MEANS

AND

AND

PARKE

TABLE 1 OF TRIALS T O CRITERION FOR ALL SUBGROUPP OF Ss

SDS

AND ERRORS

Boys High

Arousal,

Isolation

Trials

Low

Errors

Arousal,

Isolation

Trials

Errors

Reward

Mean

SD

hfean

SD

Mean

SD

Mean

SD

Verbal Material

20.8 17.0

17.82 13.02

5.8 3.2

9.22 4.93

50.4 47.2

28.76 27.11

22.2 20.2

17.44 17.43

High

Arousal,

no Isolation

Trials

Verbal Material

Low

Errors

Arousal,

no Isolation

Trials

Mean

SD

Mean

SD

Mean

36.4 24.2

24.22 12.07

15.4 8.6

11.88 6.83

34.8 25.4

Errors

SD 31.51 27.43

Mean

SD

15.4 7.0

19.72 11.56

Gi: IS High

Arousal,

Isolation

Trials

Verbal Material

Errors

Arousal,

Isolation

Trials

Errors

Mean

SD

Mean

SD

Mean

SD

Mean

SD

20.2 30.2

10.81 26.73

4.2 8.8

3.82 12.42

19.6 47.4

16.31 27.16

5.4 20.4

7.86 16.13

High

Arousal,

no Isolation

Trials

Verbal Material

Low

Low

Errors

Arousal,

no Isolation

Trials

Mean

SD

Mean

SD

Mean

28.2 20.8

24.83 12.62

9.6 6.8

11.76 6.79

53.6 43.0

Errors

SD 25.29 27.25

Mean 26.0 18.0

SD 11.06 13.74

a N = 5 in each subgroup.

continued. Moreover, the effects of the experimental manipulation might be expected to be most marked, and most important as a determinant of performance, near the commencement of the learning task. The data for boys and girls were combined in order to increase the number of

EMOTIONAL

AROUSAL,

ISOLATION,

AND

TABLE FINGER

2

TEMPERATURE

CHANGES

High Arousal Change Fall No change or slight rise

Isolation 17 3 Chi-square

169

DISCRIMINATION

Low Arousal

No Isolation 13 7

Isolation 7 13

No Isolationn 7 12

= 13.87; p < 0.001

(1The data for one S were lost on account of a loose thermistor

probe.

cases in each cell and thus permit a chi-square test. This test indicated that the distribution of Ss under the four experimental conditions significantly differed. As a further check on the relationship between temperature fall and speed of learning, the mean number of trials to criterion was calculated for all Ss who showed a drop in finger temperature and also for all SS whose temperature did not drop. These means were 26.45 and 38.63, respectively, a difference large enough to reach significance (t = 2.13; p < 0.05, for 77 elf). DISCUSSION

The results of this study and those of previous related investigations (Walters and Ray, 1960; Walters, Marshall, and Shooter, 1960) indicate that children learn a relatively simple task more readily when their arousal level is moderately high than when their arousal level is low. Walters and Ray interpreted similar findings as indicating that reinforcers are more effective if the recipient of reinforcers is anxious or aroused. However, there is also evidence that observational learning that occurs in the absence of reinforcement is facilitated if the observer is aroused (Bandura and Walters, 1963). Consequently, a more general explanatory principle is required to account for the effects of arousal. One possible explanation is that under moderate emotional arousal the learner is more attentive to relevant cues (Easterbrook, 1959; Kausler and Trapp, 1960). If this is so, it is reasonable to suppose that children under our high-arousal conditions confined their attention more closely to the visually presented stimuli, so facilitating the recognition of differences, and were also more alert to the associations between their choices and the responsesof the experimenter. Erickson (1962) reported more effective verbal conditioning in children who had been deprived of adult contact than in children with whom an adult had been continually communicating during a 15-minute “digit

170

WALTERS

AND

PARKE

game.” Moreover, improved learning following deprivation was apparent only when verbal approval was used as the reinforcer; when reinforcement consisted of marbles delivered by a dispenser, deprived and satiated groups of children did not greatly differ. In fact, Erickson’s graphs suggest that conditioning was successful only with subjects who had been first deprived of social interaction and then rewarded with verbal approval. Erickson’s marble-dispensing procedure was not, however, comparable to the manner in which material rewards were dispensed in the present study. Under our material-reward condition, S’s were explicitly set a discrimination task and were told that the tokens they received for correct responses could be later exchanged for a prize. In Erickson’s experiment, the children who received marbles were not told that these signified the occurrence of a correct response or could be interpret.ed as rewards. Under these circumstances, it seems unlikely that the dropping of a marble was an adequate stimulus for the production of discrimination learning. Moreover, the intrinsic reward value of a marble is probably highly dependent on the sex and age of a child and whether the marble season is “on.” Erickson included girls as well as boys and used Grade 6 children, who are beyond the age at which marbles arouse maximum interest; no information is given concerning the time of year when her children were tested. Finally, she did not tell the children that they might keep any marbles that were delivered. Consequently, the marbles probably lacked incentive value, in addition to being inadequate as discriminative stimuli. The above objections do not, of course, apply to Erickson’s findings for verbally reinforced children, who learned more readily after social deprivation. Her deprivation procedure, however, was more of a withdrawal-of-attention operation than a simple isolation condition; her E first gave the children instructions and practice for the verbal conditioning t,ask and then withdrew her attention while remaining in the room with the child. Somewhat similar procedures have been shown to lead to faster learning in nursery-school children (Hartup, 1958). In fact, Erickson’s findings for the verbally reinforced group arc consistent with the view that a variety of conditions, including both withdrawal of reinforcers and the creation of threat, may produce emotional arousal and consequently more effective learning in social situations (Bandura and Walters, 1963). The design of the study did not permit a full examination of the cross-sex effect reported by Gewirtz and Baer (1958a,b), who noted that social isolation was more likely to enhance the reinforcer effectiveness of verbal approval when the E was of the opposite sex from the Ss.

EMOTIONAL

AROUSAL,

ISOLATION,

AND

DISCRIMINATION

171

Some data relevant to this cross-sex effect were, nevertheless, secured. When the arousal manipulation was omitted and verbal approval served as the reinforcer, isolated girls took considerably fewer trials to learn the discrimination t.ask than did isolated boys. In fact a selective post hoc t.wo-tailed Mann-Whitney test indicated that the difference, which is in the opposite direction to that noted by Gewirt,z and Baer, had reached significance (U = 2 for n, = 5, n, = 5; p = 0.032). However, not too much weight should be placed on this finding, since the five girls in question performed, on the average, as well as, or better than, most other subgroups of Ss, including those under the high-arousal isolation condition. Moreover, the Ss in our study were considerably older than the nursery-school children used by Gewirtz and Baer; cross-sex effects, which are by no means confined to adult, interactions with previously isolated children, seem to vary according to the age of the Ss (Stevenson, 1961). Although t,he analyses of variance of trials to criterion and errors yielded no clearly significant interaction effects, the anxiety X isolation x sex interactions approached significance (p < 0.10). This trend was largely clue to the relatively poor performance of boys under the lowarousal-isolation condition, a finding that is again at variance with the Gewirtz-and-Baer hypothesis concerning cross-sex effects in relation to isolation. According to the social-deprivation theory, it is the nature of approval or attentiveness as a specifically social reinforcer t,hat accounts for the heightened susceptibility to social influence of children who are rewarded for conformity following social deprivation. Our failure to find any interaction effects involving isolation and type of reward suggests that this aspect of the theory is mistaken and consequently lends some support to the arousal hypothesis, which demands only that the rewards be appropriate to the age, sex, and socioeconomic status of the recipients. Perhaps the weight of evidence would have been greater if an automatic dispenser had been used to deliver the material rewards. However, the manner in which material rewards were dispensed closely approximates automatic dispensing, except for the fact that the E was quite evidently the controller of resources. It may even be claimed that our procedure is the better parallel to the dispensing of “nonsocial” rewards in real-life situations, in which material rewards arc ordinarily perceived as being mediated by socialization agents. In any case, the manner in which the material rewards were dispensed involved a minimum of social interaction and departed radically from the conditions under which, according to Gewirta and Baer, reinforcer effectiveness should be enhanced. Since S was permitted initially to select the twin hc would call Bill,

172

WALTERS

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PARKE

it is possible that arousal facilitated learning only because, in the twochoice discrimination task, the “correct” discrimination was prepotent in 8s’ response hierarchy to the pairs of perceptual stimuli. In this case, of course, the results would be consistent with Spence’s (1958) theorizing concerning the influence of strength of drive on learning. In the study by Walters and Ray (1960), however, the LLcorrect” response was S’s nonpreferred choice during the first 4 (baseline) minutes of responding in a two-choice situation. Nevertheless, these findings are only paradoxical if one fails to distinguish situationally induced arousal or “anxiety” from “anxiety” or “emotionality” as a personality characteristic that may be assessed from paper-and-pencil tests. Whereas inventory and questionnaire measures of anxiety such as the MAS may reflect primarily the range of cues to which a person will respond in an emotional manner, physiological measures of arousal and self-reports of reactions to specific threatening situations may reflect primarily the intensity with which the subject reacts. If this speculation is correct, one would not expect “manifest anxiety” and “emotional arousal” to influence learning in precisely equivalent ways (Walters and Parke, 1964). A fairly lengthy series of isolation studies has thus led to several conclusions. In the first place, there is some evidence to support the hypothesis that isolation may, under some circumstances, be a conditioned stimulus for “anxiety.” This conclusion can draw further support from Schachter’s (1959) studies of affiliation. Second, isolation may be a condition under which ‘(anxiety” induced by preceding events may mount, again a conclusion that is consonant wit’h Schachter’s data. Third, moderate emotional arousal (accompanying or not accompanying isolation) may lead to faster learning, at least of some kinds of discrimination tasks. Finally, it is now proposed that this faster learning is in no way related to changes in reinforcer effectiveness, but rather reflects the improved perceptual organization and cue utilization that appears to accompany moderate emotional arousal. REFERENCES A., AND WALTERS, R. H. Social learning and personality development. New York: Holt, 1963. BINDRA, D. Motivation: a systematic reinterpretation. New York: Ronald Press, 1959. EASTERBRODK, J. A. The effect of emotion on cue utilization and the organization of behavior. Psychol. Rev., 1959, 66, 183-201. ERIKSON, MARILYN T. Effects of social deprivation and satiation on verbal conditioning in children. J. camp. physiol. Psychol., 1962, 55, 953-957. GEWIRTZ, J. L., AND BAER, D. M. The effects of brief social deprivation on behaviors for a social reinforcer. J. abnorm. sot. Psychol., 1958, 56, 49-56. (a)

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