Effect of Group Relationship and of the Role of Leadership upon Lipid Mobilization

Transcription

1 Effect of Group Relationship and of the Role of Leadership upon Lipid Mobilization MORTON D. BOGDONOFF, M.D., ROBERT F. KLEIN, M.D., KURT W. BACK, Ph.D., CLAUDE R. NICHOLS, M.D., WILLIAM G. TROYER, M.D., and THOMAS C. HOOD, B.A. The physiologic lesponses ot man occurring during situations ot social interaction have been speculated on as being of possible importance in the evolution of cardiovascular disease. Since alterations in lipid metabolism may contribute to the development of some types of cardiovascular disease, a series of studies of the relationship between various types of social interaction and the process of lipid mobilization have been conducted. The results indicate that the type of social relationships that existed for the subjects prior to the experimental study significantly influenced the physiologic response of the individual during the study and that the effect of agreement or disagreement among the group upon lipid mobilization also depended upon the established social interaction. A HE RELATIONSHIP between different qualities of social interaction and various physiologic responses has recently become the focus of investigation in several laboratories. 1 " 4 The potential significance of this research for the phy- From the Deparlim-iiU of Medicine, Sociology, and Psychiatry, Duke University, Durham, N. C. This investigation was supported, in part, by the Life Insuranee Medical Research Fund, Duke University Center for the Study of Aging (HD ), and in part, by a grant from the Office of Naval Research Group Psychology Branch, Contract No [11], Project NR , and the U. S. Public Health Service Grant MH Presented at the Annual Meeting of the American Psychosomatic Society, Apr. 4, 1961, San Francisco, Calif. Received for publication Apr. 5, sician reside 5 in the suggested importance of social role (and the psychological features of that role) as a contributing factor to the development of disease particularly cardiovascular disorders. 5 ' The pathophysiological mechanism mediating such an interaction is not known. However, since alterations in lipid metabolism may be related to the development of cardiovascular disease, the effects of various psychological and social experiences upon lipid metabolism would appear to merit specific investigation in an attempt to develop an understanding of these mechanisms. With this perspective in focus, we have during the past several years, studied in detail the effects of several types of life experiences upon an important dimen- 710

2 BOGDONOFF 7 AL 711 sion in lipid metabolism, namely, the process of lipid mobilization. 7 These studies have indicated that the process of lipid mobilization is acutely responsive to modifications of psychological arousal, and, furthermore, that the behavioral response that accompanies an arousing stimulus may significantly alter the magnitude of the physiologic response. As an extension of our initial observations, we have studied the relationship between the specific characteristics of certain social interactions and the process of lipid mobilization, and it is the purpose of this report to summarize the results of these studies. tionnaire concerning some general life history data (site of birth, home, schooling, health record, general interests, interpersonal-relationship ratings, etc.) and following this period, a "resting" or "sample No. 2" was drawn. The four subjects were then brought into the experimental study room and placed before the testing equipment (Fig. 1). Experimental Task The task consisted of performing a rapid, visual identification: comparing length of lines (Fig. 2). The slide was flashed on the screen which was placed before the group of subjects. The length of time the slide was exposed was varied according to the Methods Subjects AH subjects observed in these studies were white, male undergraduate students at Duke University. The age range was years. All individuals were considered to be in good health and free of any metabolic disorders such as diabetes or marked obesity. The manner in which the subjects were recruited for the study served as one of the experimental variables and is described below. Procedure The studies were conducted in the morning (8 11 A.M.) in the Behavioral Medicine Laboratory. All subjects had been asked to fast overnight (12-17 hr.). Water was allowed in the morning, but cigarette smoking was restricted. Groups of four subjects each were studied during each experimental run. Shortly after arrival at the laboratory, the general purpose of the study was reexplained by one of the experimenters: "We are interested in the changes in blood fats that occur when groups of people attempt to perform a special task...." Blood pressure and pulse were then recorded and an indwelling Coumand needle was placed in an antecubital vein. An initial blood sample was then drawn, usually described as "sample on entry" or "No. 1." The subjects were then given a pencil-and-paper qnes- VOL XXVI. NO. 6, 1964, - 1 FIG. 1. (top) Group of four subjects seated in individual booths. FIG. 2. (bottom) Slide on screen: Lines are matched against lefthand line.

3 712 LEADERSHIP AND LIPID MOBILIZATION design of the study: the shorter the exposure, the more difficult the task (1 sec, in this study). Experimental Setting The experimental arrangement used in our laboratory is a modification of the technique described by Crutchfield. 8 ' 9 Each individual subject was seated in his own booth, in which a panel of lights and buttons was located before him (Fig. 3). After he was seated, the subject was asked to pick up and read a card lying on the shelf in the booth. This card indicated to him whether he was subject A, B, C, or D. The topmost center light of his panel was described as his "signal" light and would become lighted when he was to give his answer to the visual task. He was to indicate his answer by pushing one of the buttons (1, 2, or 3) at the top of his panel. The answers of the "other" subjects would appear on his board as various lights would flash on. Through a master control panel in the projection booth it is possible to light up any light on any panel and thereby experimentally program the "answers" of the "other" subjects that appear before each individual. In this manner, the responses of the individuals of the group with whom the subject is being studied may be controlled by the experimenters. Thus, the technique provides a method to create certain types of interaction among the individuals of a group while they are performing a challenging task. By means of the indwelling Cournand needle, sequential samples of blood may be drawn during the course of the procedure (Fig. 4). Social Interaction Variables The two specific characteristics of social relationship that we wished to study were "friendship" among the individuals, and the fulfillment of the role of "leadership" for the group. The variable of "friendship" was developed by the technique through which the groups were recruited for the study. One type of recruiting announcement (on the undergraduate bulletin board) stated that "groups of four volunteer subjects" were needed for a study. This type of announcement resulted in one or two individuals FIG. 3. (top) Panel of lights before each subject in individual booths. Signal light at top of panel is lighted, and answer No. 3 is lighted for all four subjects. FIG. 4. (bottom) Subject seated before panel. In this study, he is subject D; the signal light is on, "other" subjects A, B, and C have answered No. 3, and he is about to answer No. 1.

4 BOGDONOFF T AL. 713 getting together a group of four from among their "mutual friends" on the campus and reporting to the laboratory together to volunteer for the study as a group. These groups were considered to consist of "friends" and have been so denoted in our studies. A second type of announcement stated that "volunteer subjects" were needed. Individuals usually reported alone to the laboratory and we then assigned four such individual subjects to participate in a specific experimental run. These groups of four individually recruited subjects were considered to consist of "strangers" and are so denoted in our studies. At the very close of the study, in order to obtain an independent measure of whether or not the subject groups did differ in terms of previously knowing one another, a questionnaire was administered in which the subject rated how well he knew the other subjects. The scale ranged from 0 ("did not know") to 3 ("very close friends"), and if all three other subjects in the group were close friends, the total rating was 9. The mean "friendship" scores for the groups of "friends" was 6; for the groups of "strangers" it was 1. Furthermore, there were no groups of "strangers" with individuals with more than one mutual friend, whereas all groups of "friends" were made up of two or more mutual friends. The post-test ratings are significant at the.005 level. The role of "leadership" was created by manipulation of the manner in which the "answers" of the "other" subjects were flashed on the panel. An example of such a manipulation is as follows: Individuals were shown their signal light before any panel lights flasned on. An answer button would then be pushed bv that individual. Whatever his answer was, the "answers" of the "others" were flashed on the panel in sequence as being similar to his own. Repeated trials in which the "answers" of "others" always (100%) matched the individual's own answers are considered to have created the role of "leadership." In contrast to this pattern of agreement, the "other" subjects may be shown to "disagree" and not to follow the initial choices of the individual. The effect of this type of social interaction has also been studied. It is possible to assess the individual's VOL. XXVI, NO. 6, 1964 ability to make independent judgments once he has seen the answers of the other subjects. The frequency with which the individual "copies" or "conforms" to the decisions of "others" may be measured if the individual's signal light goes on after the "answers" of all the "other" subjects are lighted. In the last phase of the study this testing situation was established. At the conclusion of the study, the indwelling needle was removed and a thorough explanation of the procedure and methods was presented to the subjects. A post-experimental interview indicated that none of the subjects had suspected the true nature of the mechanics of the experiment. Experimental Sequence As illustrated at the base of Fig. 6, the study was divided into four periods: (1) immediately following entry, and then a min. resting period (2) instructions in the task, followed by a sequence of 20 task trials in which the "answers" of "others" was not flashed on the board, and during which an actual skill score of the number of correct answers made by the subject was recorded (15-20 min.) (3) establishment of "leadership" by group "agreement" or no leadership established by "disagreement" and (4) the conformity phase. Lipid Mobilization The direction and magnitude of the process of lipid mobilization was assessed by sequential samples of venous blood analyzed for plasma FFA content. As was reviewed in detail previously, 7 serial levels of FFA in a fasted, nonexercising individual provide an index to the degree that peripheral depot triglyceride is being mobilized fiom the lipid stores to supply energy substrate for the metabolic demands of muscle and other tissues. This process is significantly influenced by a number of neurohumoral factors and, in the studies reported here, the effect of alterations in autonomic nervous system activity may be considered to play an important role. Plasma FFA levels were determined by a modification of the method of Dole. 10

5 714 LEADERSHIP AND LIPID MOBILIZATION On Sample Entering # 2 TIME OF SAMPLE FIG. 5. Plasma FFA levels for "friends" and "strangers" during the initial phase of the studv. Results Six groups of four subjects each of "friends" and six groups of four subjects each of "strangers" were studied. Fig. 5 illustrates the plasma FFA levels during the initial phase of the study. At the outset, the mean FFA level for all subjects in the "friends" groups was 693 /teq./l.; the mean initial level for the "strangers" was 798 /<.Eq./L. (the difference between these means is significant at the 0.01 level). The mean level at sample No. 2 for the "friends" was 600 /teq./l.; for the strangers, 749 /xeq./l. (p = < 0.01). The percent decrease from samples No. 1 to No. 2 is greater in the "strangers" (23%) than in the "friends" (13%), both decrements, however, being comparable to the initial decreases in FFA levels that have been previously observed in the experimental laboratory situation. 7 During the next phase of the study, all groups of subjects were instructed in the task and a series of trials were performed. Figure 6 demonstrates the pat- FIG. 6. Plasma FFA levels for "friends" and "strangers" throughout entire course of study. Total time for entire study from sample No. 1 to sample No. 5 was approximately 90 min. tern of FFA levels for all persons in the study and the results during the second phase are illustrated there. In all groups, there was a prompt and sharp rise in plasma FFA levels "friends:" mean increase -(- 138 jteq./l.; "strangers:" mean increase /JEq./L. The difference between these rises approaches but does not arrive at a point of statistical significance, though the range of the levels for the two different types of groups is still significantly different (p = < 0.01); mean sample No. 3: "friends," 738 /leq./l.; "strangers," 921 /xeq./l. The next phase of the study included the establishment of the role of "leadership." As indicated in the methods section, the role of "leader" in these studies was presumably created when the "answers" of the "other" subjects agreed 100% of the time with the individual's own answers (indicated as "agreed" in Fig. 6). The role of "leadership" was not created when the "answers" of the "other" subjects disagreed 80% of the trials. There were, therefore, four different sets PSYCHOSOMATIC MEDICINE

6 BOGDONOFF ET AL, 715 of subjects during this phase of the study: 1) "friends" who were "agreed" with-and, therefore, established as "leaders"; 2) "friends" who were "disagreed" with (no leaders); 3) "strangers" who were "leaders"; and 4) "strangers" without "leaders." Mean plasma FFA levels rose in all but one of the groups ("friends-leaders": 4 jueq./l.), most markedly in the "strangers-leaders," -(-110 /aeq./l. Figure 7 compares the percentage change in plasma FFA levels during this phase, using the resting level (sample No. 2) as a reference point. As was mentioned in the methods section, the final phase of the experimental sequence was designed to afford an opportunity to study the effect of the decision-choice of "others" upon the decisions of the individual subjects. In order to do this, the signal lights of the individual subjects were flashed on the board after the "answers" of the "other".subjects appeared on the panel so that the individual subject sees what the "other" people are deciding before he gives his answer. One of the purposes of such an arrangement is to permit a measure of the individual's tendency to "copy" or to "conform" to the decision of the people around him, and it is possible to calculate an index of conformity. 11 During this phase of the study, plasma FFA levels rose in both groups of "friends" ("leaders": /ieq./l.; no leaders: + 46 peq./l.), and fell in both groups of "strangers," ( 88 /ieq./l. and 18 /ieq./l.) (p <.05). The amount of "copying" or "conforming" behavior among the two group.) also differed. There was considerably more conforming behavior amon^ th? "friends" (conformity index =.3 in "friends";.15 in "strangers" (p <.001), and, furthermore, the rise in FFA that occurred among "friends" during the last portion of the study was least marked for those individuals who conformed the most. 8 S < 4 2- I i Agree Disagree Agree Disagree STRANGERS FRIENDS FIG 7. Change in plasma FFA level in four different types of groups during "leadership" phase of study. Change in plasma FFA level is calculated as the percentage increase during phase, using the "resting" (sample No. 2) value as point of comparison since this level represents point in study where fewest experimental variables have been introduced. Discussion The results of the studies reported in this presentation indicate that the characteristics of social interaction do significantly modify the physiological responses that accompany a challenging task. When an individual participates in a laboratory testing experience in the company of his "friends," the magnitude of his physiological response is consistently less at several stages of this experience. As indicated by the levels of plasma FFA, the degree of neurohumoral activity is relatively less from the very outset of the study, and this difference in level of lipid mobilization persists until the very close of the period of observation. Thus, we might infer that the intensity of arousal as reflected by the VOL. XXVI, NO 6, 1964

7 716 LEADERSHIP AND LIPID MOBILIZATION degree of lipid mobilization is significantly diminished for individuals who enter upon a challenging experience in the company of people they have previously known than for individuals who are working among "strangers." Furthermore, above and beyond this persistent difference in arousal that separates the two types of groups throughout the study, there is the diminished degree of lipid mobilization that occurs among "friends" during the actual performance of a difficult task. Thus, not only is the general set different for an individual when he is among his "friends," but the specific response to a circumscribed challenge is also of a lesser magnitude than for a man among "strangers." These observations, which suggest that an individual's physiological responses are altered when he is in the company of several people with whom he may have a more positive and supportive relationship ("friends") may be viewed as being analagous to two-person interaction studies previously reported from other laboratories. Reiser et al. demonstrated that alterations in the magnitude of ballistocardiograph change, and variations in the blood pressure responses following a specific stimulus were determined, in part, by the relationship between the experimenters and the patient. His studies were made utilizing personnel in the armed services, and he observed that if both individuals were enlisted men the physiological changes were less than when the experimenter was an officer and the subject was an enlisted man. 12 Malmo and his group reported that the tension in the muscles of the neck of a patient which occurs at the outset of a doctor-patient interaction decreases more rapidly when the physician is supportive to the patient than when the physician appears more critical. 13 Similarly, Greenblatt and his associates demonstrated that changes in the heart rates of patients during interviews were significantly related to the "positive" or "negative" characteristics of the interaction between the patient and the physician. 14 We have interpreted the results of our studies, therefore, to represent an extension of the two-person, doctor-patient interaction studies cited above. It is our thesis that when an individual is interacting with his "friends" he is, in effect, experiencing a "supportive" transaction with the others about him, and it is this quality of the interaction that has led to the diminished physiological response accompanying the entire laboratory experience. The final two phases of the study were designed to measure both the physiological and behavioral (tendency to conform) responses following the assignment of the implied role of "leadership." The application of this type of social interaction produced disparate effects for the two groups. The assumption of "leadership" among "friends" (to be agreed with 100% of the time) was accompanied by little or no change in FFA levels; however, the establishment of the leadership role among "strangers" resulted in further rises in FFA level. "Disagreement" among "friends" or among "strangers" produced approximately the same degree of change (Fig. 7), but it is important to point out that the changes for "disagreement" among "strangers" is less than for "agreement" among "strangers." In attempting to understand the possible meaning of these results we have considered utilizing the physiological changes as an indicator by which we might judge the social meaning of the experimental situation. Thus, one might conclude that those situations that are accompanied by the most marked physiological changes are the ones which evoke the most marked degrees of arousal. In the present experiment, the FFA changes are greatest for both groups when "friends" are "disagreed with" and when "strangers" are "agreed with," PSYCHOSOMATIC MEDICINE

8 BOGDONOFF ET AL. 717 thereby suggesting that arousal is greatest when the experimental manipulation tends to displace the established social order. In other words, to have "friends" no longer agree (break up the group) or to create agreement among "strangers" (create a group) effects the most marked degree of neurohumoral response. Such an interpretive formulation would be consonant with the long-standing principle in sociological research that any force that tends to disrupt the established pattern of social interaction will produce a reactive response to the attempted change. The behavioral responses, as measured by the conformity index, during the next and final phase of the study might also be interpreted with that thesis in view. The index of conformity was significantly higher among "friends" (a tendency to maintain the closeness of "friends") than among "strangers" where it was quite low (no attempt to maintain a tightly related group; almost complete independence of judgement by the individuals). We might, therefore, conclude that conforming behavior for "friends" maintained the established social order whereas conformity would be inappropriate among "strangers" and consequently disruptive to the existing social order. The physiological responses during this phase may also be used to speculate upon the stimulus qualities of the experimental conditions. FFA levels decreased for the "strangers" and increased for the "friends" suggesting that this phase was generally more arousing for the latter group. This difference in response might be explainable in light of the fact that there is an implied conflictual situation in the design of this segment of the study. On the one hand, the subject is being asked to perform as well as possible by providing his own correct answer to the difficult task; on the other hand, he is now able to see what "others" have done before him, and there is consequently the opportunity to VOL. XXVI, NO. 6, 1964 "copy" or "cheat." If one is among a group of "strangers" the opportunity to "copy" may not be very important or meaningful, but when one is among "friends" the "other fellow's answers" may be much more important to consider. Therefore, in this final phase, we might postulate that there is greater pressure to conform or "copy" among "friends" and that since this behavior may not appear to be quite acceptable according to the implied ground rules of the study, this situation is more arousing for this group, and FFA rises are then observed. However, among "strangers" there is no similar pressure to conform; the experimental situation, therefore, is less meaningful, and, consequently, FFA levels decrease. Furthermore, the observation among "friends" that there is less of an increase in plasma FFA levels for those individuals who conform the most (negative correlation between plasma FFA level rise and index of conformity) would suggest that "conforming" or "copying" provides a behavioral solution to the conflictual characteristics of this phase and that the individual, when he actually utilizes this path of behavior, reduces the magnitude of arousal. Conforming behavior in these circumstances may, therefore, be viewed as reducing, in part, the psychophysiologic reaction of the individual to the stimulus situation. In our previous studies we also observed such a modifying effect of conformity upon psychophysiologic reactivity. 11 In attempting to understand the results of the present studies as part of a meaningful perspective that also includes the relationship of social factors to the evolution of clinical problems, we have proposed the following formulation. First, we have interpreted increased degrees of lipid mobilization as representing evidence of increased degrees of neurohumoral activity, particularly of the autonomic nervous system. Second, we have equated increased neurohu-

9 718 LEADERSHIP AND LIPID MOBILIZATION moral activity with an established displacement from some point of homeostatic balance for any one individual; and, third, we have assumed that the greater the displacement that an individual experiences in response to any one stimulus the greater the cost in terms of the "wear and tear" of the organism. In the studies reported here the presence of "friends" during the experience of participating in a challenging laboratory experiment and the role that the individual may play in relationship to the group around him are factors which significantly modify the process of lipid mobilization. These factors may be viewed as elements in the stimulus-response equation which tend to minimize the individual's displacement from homeostatic balance. It would seem reasonable, therefore, to postulate that the "wear and tear" upon an individual as he progresses through the many stimulus-response events of daily living may also be significantly modified by the social interactions he is experiencing. If these interactions tend to maintain homeostasis, then we would predict relative protection against the development of disease; if these interactions tend to enhance physiologic reactivity then we would predict that these interactions would promote disease development. The studies of Hinkle and Wolff 15 would indicate that this thesis merits further study and investigation and that a major next step in psychophysiologic research in man must be ventured in this area of endeavor. Summary 1. The interrelationship between a series of social interaction variables and the individual's physiologic responses during the performance of a challenging task has been studied in a series of young male college students. 2. The variables of "friendship," "leadership," and the opportunity to "conform" were observed in 12 groups of four individuals; sequential changes in plasma FFA levels were used as an index to the process of lipid mobilization. 3. Those individuals who were recruited together and considered to be "friends" demonstrated lower levels of plasma FFA throughout the study, demonstrated less of a rise during the performance of the task, reacted with greater rises to the role of "no leadership," and "conformed" more during the final phases of the study. 4. Those individuals who were considered to be "strangers" demonstrated higher levels of FFA, greater changes to the task, and, also reacted with greater FFA changes to the role of 'leadership."' 5. These small-group, social psychophysiological studies may provide an experimental model for relating the course of clinical illness to the occurrence of significant social variables in the environment of the patient. Department of Medicine Duke University Medical Center Durham, N. C. References 1. LF.IDERMAN, P. H., and SHAPIRO, D. A physiological and behavioral approach to the study of group interaction. Psychosom. Med , KAPLAN, H. B. Social interaction and GSR activity during group psychotherapy. Psychosom. Med. 25:140, KAPLAN, H. B., BUBCH, N. R., BLOOM, S. W., and EDELBERG, R. Affective orientation and physiological activity (GSR) in small peer groups. Psychosom. Med. 25:245, LEIDERMAN, P. H., and SHAPIRO, D., Eds., Symposium on Psychobiological Approaches to Social Behavior. Stanford University Press, MORRIS, J. N. Occupation and coronary heart disease. Arch. Internat. Med , PSYCHOSOMATIC MEDICINE

10 BOGDONOFF ET AL CHRISTENSON, W. N., and HINKLE, L. E., JR. Differences in illness and prognostic signs in two groups of young men. J.A.M.A. 177:247, BOGDONOFF, M. D., and ESTES, E. H., JR. Energy dynamics and acute states of arousal in man. Psychosom. Med. 23:23, CRUTCHFIELD, R. S. Conformity and character. Am. Psychologist JO. 191, GERARD, H. B. Disagreement with others, their credibility and experienced stress. /. Ahncrm and Social Psychol. 62:559, TROUT, D. L., ESTES, E. H., JR., and FRIEDBERC, S. J. Titration of free fatty acids of plasma: a study of current methods and a new modification. /. Lipid Res , BOCDONOFF, M. D., BACK, K. W., KLEIN, R. F., ESTES, E. H., JR., and NICHOLS, C. R. The physiologic respouse to conformity pressure in man. Ann. Int. Med. 57:389, REISER, M. F., REEVES, R. B., and ARMINGTOX, J. Effects of variations in laboratory procedure and experimenter upon the ballistocardiogram, blood pressure and heart rate in healthy young men. Psychosom. Med. i7:185, MALMO, R. B., BO\G, T. G., and SMITH, A. Physiological study of personal interaction. Psychosom. Med. J9.-105, Di MASCIO, A., BOYD, R. W., and GHEENBLATT, M. Physiological correlates of tension and antagonism during psychotherapy: a study of "interpersonal physiology." Psychosom. Med. 19:99, HINKLE, L. E., JR., and WOLFF, H. G. Ecologic investigations of relationship between illness, life experiences, and social environment. Ann. Int. Med , Rare Back Issues of Psychosomatic Medicine The Executive Office of the American Psychosomatic Society has available for sale, on a first-come, first-served basis, certain volumes of Psychosomatic Medicine. The issues for 1941, 1942, and 1945 are available at $15.00 per volume. The issues for 1959, 1960, and 1961 are available at $8.50 per volume. In addition, some single numbers are available from 1939 to 1963 at $2.00 per copy. Inquiries should be addressed to Joan K. Erpf, Executive Assistant, American Psychosomatic Society, 265 Nassau Road, Roosevelt, New York VOL XXVI, NO. 6, 1964