Appendix A: Initial Operations, June-October 1969On June 3, 1969, HEW Secretary Robert H. Finch announced the appointment of the Surgeon General's Scientific Advisory Committee on Television and Social Behavior. The committee's mission: to study the effects of television on social behavior, with its focus on the effects of televised violence on the behavior, attitudes, development, and mental health of children; the study is to be confined to scientific findings and the committee will make no policy recommendations.
Secretary Finch noted that if the study reveals there is an adverse connection between violence and television and mental health of children, it is likely that corrective action will be taken by the broadcast industry on a voluntary basis.
The original framework for the study had been laid down by Surgeon General William Stewart in his testimony, on March 12, 1969, before the Senate Subcommittee on Communications. Dr. Stewart said that there is little doubt that television has an impact on the viewing public. He pointed out that the average American child, by age 16, has spent more hours in front of a television set than in a classroom.
The Surgeon General stated that the task "cannot be accomplished by narrow Iy focused studies, since the violence a child sees on television is randomly interwoven into the total skein of television fare . . . . it is essential to recognize that, with such a complex phenomenon, all the answers will not be forthcoming within the next few weeks or the next few months. The panel's findings and recommendations should be an important step in increasing our understanding of our social environment and of ourselves. "
Thus the committee's work is concerned with producing new knowledge and will not restrict itself to reexamining existing information. A series of new research projects is now being developed which will increase our understanding of the effects of mass media and to answer the Surgeon General's question, "What kind of impact and how does it influence behavior?"
Early inquiriesEarly research of televised programming consisted mainly of limited studies and recorded testimony from scientists, educators, and irate parents.
The first public examination was taken in the early 1950s when the National Association of Educational Broadcasters, under a Ford Foundation grant, conducted monitoring surveys in four large cities. [1] The surveys found that in each of the four cities, drama accounted for about one-fourth of the total programming time; drama of crime and horror comprised approximately ten percent of all programming time. This percentage jumped when westerns were included in this category.
The issue of the effect of television violence on human behavior was brought up before the Congress of the United States in 1954 by the late Senator Estes Kefauver, who headed the Subcommittee to Investigate Juvenile Delinquency. That committee launched hearings in response to mounting concern of parents and educators over the amount of time devoted to shows containing crime, brutality, sadism, and sex. Based on the testimony, the committee issued a report indicating that it felt television violence could be potentially harmful to young viewers. [2]
Representatives of television networks acknowledged the large amount of televised violence and promised to change the content, but subsequent surveys by the Senate subcommittee, in 1961 and 1964, revealed that the degree of violence in prime time programming had substantially increased. After this third survey in 1964, the overriding conclusion of the subcommittee was that "the extent to which violence and related activities are depicted on television today has not changed substantially from what it was in 1961 and remains greater than it was a decade ago. Further, violence and other antisocial behaviors are, to an overwhelming degree, televised during time periods in which the children's audience is a large one."
In 1964, Senator Thomas Dodd held hearings to review what had happened in the past three years, and he reported: "Not only did we fail to see an appreciable reduction of violence in new shows, but we also found that the most violent shows of the 1961-62 season have been syndicated and are now being reshown on independent networks and stations. "
The Dodd committee reported that a relationship has been established between televised crime and violence and antisocial attitudes and behavior among juvenile viewers. [3] The report added: "And we are greatly impressed by television's achievements in the public areas and by its potential for good in both the education and entertainment fields. Yet it seems clear that television has been functioning as what an informed critic has termed 'a school for violence'. "
On June 10, 1968, President Lyndon Johnson charged his newly created National Commission on the Causes and Prevention of Violence with answering the question, "Are the seeds of violence nurtured through the public's airways . . . that reach the family and our young?"
In addition to holding hearings and reviewing existing research, the Commission undertook a content analysis of a week of entertainment television programming in 1967 and a comparable week in 1968, and conducted a survey of the public's actual experience with violence and its norms for violence.
On September 23, 1969, the Commission issued a statement in which it concluded that violence on television encourages real violence, especially among the children of poor, disorganized families. The Commission recommended: a reduction in programs containing violence; elimination of violence from children's cartoon programs; adoption of the British practice of scheduling programs containing significant violence only after 9 p. m. ; permanent Federal financing for the Public Broadcast Corporation; and intensified research by the networks into the impact of television. [4] The Commission's report provides a valuable synthesis of existing information, adding a new content analysis of television programming and also an analysis of attitudes of television violence. Recognizing the need for new research, the National Commission called for long-term studies and cited the importance of evaluating televised violence over a protracted period.
Scientific advisory committee formedDespite the repeated examination of televised violence in the past decade and a half, no effective or integrated program of research was initiated. And no significant financial support had been available to stimulate new research in this one area, much less in the general area of television and social behavior.
Some areas of social behavior as related to television viewing will always be in doubt. No answers stand unchallenged in our rapidly changing society. It has become obvious that a comprehensive program to stimulate research in this area is long overdue. The National Commission's recommendation for further study is another indication that the pervasive medium of television, which is so much a part of our environment, must become the object of a more scientific analysis if we are to understand its impact and use it constructively.
In March 1969, Senator John O. Pastore, Chairman of the Senate Subcommittee on Communications, wrote to Secretary Finch, requesting that the Secretary direct the Surgeon General to appoint a committee "to devise techniques and to conduct a study under his (the Surgeon General's) supervision using those techniques which will establish scientifically insofar as possible what harmful effects, if any, these programs have on children.
President Richard Nixon, in a letter to Senator Pastore, affirmed his support for the proposed study.
The Surgeon General said that if television can have a negative effect on children, it can also be a positive stimulus. "We must learn more about how to promote this latter capability, " he said, "while we learn to avoid the hazards of the former. "
The National Institute of Mental Health was charged with the responsibility for the functions of the committee. On June 3, 12 distinguished scientists were appointed to the Advisory Committee. The Surgeon General was named Chairman; Eli A. Rubinstein, Ph. D. , Assistant Director for Extramural Programs and Behavioral Sciences, NIMH, Vice-Chairman; and Richard A. Moore, Special Consultant to the Secretary, Secretary Finch's liaison with the Committee.
On June 16-17, ten days after its formation, the Scientific Advisory Committee held its first formal meeting. The general task and "mode of operation were defined as follows: (1) The Committee will serve in a scientific advisory role to the Surgeon General and to the research, to be developed by the National Institute of Mental Health when the full-time staff has been organized. (2) NIMH will serve as the central resource for the work and will be the referral point for inquiries and responses about the Committee's work. (3) The next step will be the development of research projects to obtain new knowledge about television's effects on social behavior. Approximately $1, 000, 000 has been earmarked for actual research initiated by or recommended by this committee. (4) The Advisory Committee recommended that recent relevant activities such as the work of the Mass Media Task Force of the National Commission on the Causes and Prevention of Violence be carefully examined to ensure maximum use of any recent findings in the initiation of research studies. (5) Because the present state of research in television and social behavior is the work of individual investigators and is largely uncoordinated, the Advisory Committee recommended that the NIMH National Clearinghouse for Mental Health Information provide a comprehensive and continuing source of information about research on television and social behavior. (6) The committee agreed that it would be inappropriate to take a narrow view of the problem of television and social behavior. It is therefore recomended that the research efforts be undertaken in two phases: a short-term objective of a year or two to try to obtain better immediate answers, and a long-term objective to develop a continuing comprehensive examination of the process of child development which is influenced by the impact of television on social behavior. (7) No firm completion date for the study was set.
During July, August, and September of 1969 a series of activities was initiated to launch a comprehensive program of research. A staff of professional and technical personnel was employed to serve as the program's staff secretariat. Invitations were extended to 50 research organizations and to about 100 key research scientists to participate in the program. This was done through extensive personal and telephone contact with scientists in relevant fields of research and by direct letters of inquiry to selected research centers. In addition, an announcement was placed in the Commerce Business Daily inviting inquiry about the program from qualified research organizations.
The Scientific Advisory Committee held its second meeting on September 24-25 to discuss an overall research plan and to consider a variety of research proposals in various stages of development.
Additional full committee meetings will be held periodically. At the same time, members are also individually participating in those aspects of the program development related to their specific areas of competence.
Related projects are studiedThe National Clearinghouse for Mental Health Information, NIMH, is providing the committee with information on relevant studies now being conducted by various research groups. Being compiled is a comprehensive bibliography of all published research which has some bearing in this area. A listing of about 80Q broadly relevant citations is now in development. The most pertinent of these will be made into an annotated bibliography.
Some currently active research projects funded by Federal program s relate to our goals. One researcher, over the past seven years, has investigated the factors that affect the imitation of aggressive behavior in children. Specifically, he has investigated the likelihood that children will display aggressive behavior after seeing a film which shows adults engaged in various kinds of aggressive action.
Another researcher has proposed a new line of research that attempts to map the ecology of aggressive behavior in order to understand not only the characteristics of the aggressor but also the "target" of the aggression. The study's hypothesis is that some individuals and events are more likely than others to stimulate aggressive behavior.
Another major project analyzes the forms of aggressive behavior, which are described as anger, hostility, and overt aggression. The object is to investigate ways in which people respond to provocation. Other researchers have studied the role of imitation or vicarious learning in social development.
A different line of research is investigating the factors in social development that relate to aggressive acting-out in various population subgroups. It is related to the finding that in clinically isolated delinquents and impulsive persons one's self-concept is a major influence on the likelihood of aggressive behavior.
Other research deals with the process of communication in the family setting as it related to antisocial behavior in early childhood; analyses of the problem of imitation; and the effects of mass media on altruistic behavior, family interaction, and attitude change.
Summary of proposed researchThrough an intensive effort at stimulating new research, and as a result of discussions with various scientists. a number of projects are under way and others are now under consideration. Most of these projects are being developed by leading researchers at some of the major universities in the country.
Research projects that have been initiated and other research proposals that are being considered bear on a number of interrelated issues. Central among these explorations is an effort to obtain a much better understanding of television viewing behavior and thereby establish a meaningful base for evaluating effects. One proposal attempts to assess the types of television fare viewed by adolescents but also relating these viewing patterns to such factors as parent-child communication, disciplinary practice, attitudinal similarity, and a host of demographic variables.
Along a somewhat different line of analysis, there is an attempt to study the viewing behavior of young children within the family setting. In this instance, however. the emphasis is not on the content, but rather on the process of viewing. The proposed study attempts to map the child's behavior during the period of actual viewing, with specific reference to parent-child and peer interaction and attentional variables. The study also will include comparisons between black-white and varying socioeconomic levels.
Overlaying these projects, a procedure is being developed to assess attitudes about television. The main thrust of this survey will attempt to relate program preferences and viewing patterns with a wide range of variables such as experience with aggressive activities, personal value orientation and moral development, and attitudes about aggression. The proposed survey will sample from a specified population with a wide age range and varying socioeconomic and ethnic groups.
One researcher, in response to criticism s of previous laboratory investigations, has proposed a series of interrelated experiments designed to more directly assess the effects of televised violence. This study would use stimulus materials which reflect standard television programming and will measure behaviors which directly relate to the child's daily experiences.
Much of the proposed research activity is specifically directed at children. One major project being considered begins with the assumption that the usual procedures for studying the effects of television violence may not be easily generalizable to the real world of children. The researchers suggest that the observation of televised violence does not influence the child to act out this particular scene but that, rather, such observation operates to modify the child's attitudes toward violence. They propose to study this hypothesis with a developmental approach to gain an understanding about levels of moral development and attitudes about the acceptability of violent behavior.
While others are concerned with the effects of media use, one researcher will attempt to investigate young children's patterns of media use per se, as they relate to the children's personal style, parent and peer group conflicts, and antisocial aggression.
Several researchers have designed investigations of the content of standard television fare with particular emphasis on aggressive material. One investigator has addressed himself to an analysis of physical violence in the mass media, while in another approach we will be more concerned with manifestations of verbal aggression. Still another proposal concentrates on racial and social class differences in the perception of televised violence.
The committee and the staff are examining the possibility of initiating an extensive field study in which differing television programming would be offered for two or more hours a day for a number of months to two matched audiences of children at home. This could be done through CATV. While this would be an unusual opportunity for measuring effects, there are a number of unsolved research problems which need to be considered before such a study can begin.
The framing of the total research program is complicated. Staff members are making a special effort to develop as much interrelationship and integration of the individual studies as possible. Where appropriate, common measuring instruments will be used. In certain instances the same stimulus material will be used. It also is anticipated that the various investigators collaborating with the total research program will be called in from time to time to discuss mutual problems.
No final completion date has been established for the entire effort. Much depends on the initial progress in the studies now being organized. It seems clear even at this early date that an integrated research program has been initiated. The study of television's effects on social behavior is not easily approached solely by examination in a laboratory setting. Nor can any single project -- whether an analysis of content, examination of attitudes, or even a careful exploration of viewing behavior -- provide definitive answers. What seems necessary is a comprehensive research effort which can effectively facilitate the exploration of the broad question of the relationship between television and social behavior.
The Surgeon General's Scientific Advisory Committee, therefore, is exploring many phases of the process of transmitting and receiving televised communications: in the clinical laboratory and the natural setting, on both the child and his milieu, both physical and verbal violence, televised violence in both real and fantasy form, and recognizing positive and negative elements in this powerful form of mass communication.
October 30, 1969
Appendix B: Television and Social Behavior ProgramReports and Papers
Appendix C: Experiments on Children's Imitation of Aggressive BehaviorBandura, A. , and Huston, A. C. Identification as a process of incidental acquisition of imitative responses. Journal of Personality and Social Psychology, 1(6): 589-595, 1965.
Bandura, A. , Grusec, J. E. , and Menlove, F. L. Observational learning as a function of symbolization and incentive set. Child Development, 37: 499-506, 1966.
Bandura, A. , and Huston, A. C. Identification as a process of incidental learning. Journal of Abnormal and Social Psychology, 63: 311-318, 1961.
Bandura, A. , Ross, D. , and Ross, S. A. Transmission of aggression through imitation of aggressive models. Journal of Abnormal and Social Psychology, 63: 575-582, 1961.
Bandura, A. , Ross, D. , and Ross, S. A. Imitation of film-mediated aggressive models. Journal of Abnormal and Social Psychology, 66: 3-11, 1963.
Bandura, A. , Ross, D. , and Ross, S. A. A comparative test of the status envy, social power, and secondary reinforcement theories of identification learning. Journal of Abnormal and Social Psychology, 67: 527534, 1963.
Bandura, A. , Ross, D. , and Ross, S. A. Vicarious reinforcement and imitative learning. Journal of Abnormal and Social Psychology, 67: 601-607, 1963.
Christy, P. R. , Gelfand, D. M. , and Hartmann, D. P. Effects of competition- induced frustration on two classes of modeled behavior. Developmental Psychology, 1971, in press.
Hanratty, M. A., Liebert, R. M. , Morris, L. W. , and Fernandez, L. E. Imitation of film-mediated aggression against live and inanimate victims. Proceedings of the American Psychological Association, 457458, 1969.
Hicks. D. J. Imitation and retention of film-mediated aggressive peer and adult models. Journal of Personality and Social Psychology, 2: 97100. 1965.
Hicks. DJ. Effects of co-observer's sanctions and adult presence on imitative aggression. Child Development. 39: 303-309. 1968.
Kniveton. B. H . . and Stephenson. G. M. The effect of pre-experience on imitation of an aggressive film model. British Journal of Social and Clinical Psychology. 9: 31-36. 1970.
Kuhn. D. Z. • Madsen, C. H. . Jr. . and Becker. W. C. Effects of exposure to an aggressive model and "frustration" on children's aggressive behavior. Child Development, 38: 739-745, 1967.
Madsen. c. . Jr. Nurturance and modeling in preschoolers. Child Development, 39: 221-236, 1968.
Martin. M. F. , Gelfand. D. M. , and Hartmann, D. P. Effects of adult and peer observers on children's responses to an aggressive model. Developmental Psychology. 1971. in press.
Nelson. J. D. , Gelfand. D. M. . and Hartmann. D. P. Children's aggression following competition and exposure to an aggressive model. Child Development, 40: 1085-1097. 1969.
Rosekrans, M. A., and Hartup. W. W. Imitative influences of consistent and inconsistent response consequences to a model on aggressive behavior in children. Journal of Personality and Social Psychology. 7: 429-434. 1967.
Walters. R. H. , and Willows, D. C. Imitative behavior of disturbed and nondisturbed children following exposure to aggressive and nonaggressive models. Child Development. 39: 79-89. 1968.
Appendix D: Experiments on Disinhibition of Aggressive BehaviorCHILDRENAlbert, Robert S. The role of the mass media and the effect of aggressive film content upon children's aggressive responses and identification choices. Genetic Psychology Monographs, 55: 221-285, 1957.
Emery, F. E. Psychological effects of the western film: a study in television viewing. II. The experimental study. Human Relations, 12: 215-232. 1959.
Feshbach, Seymour, and Singer, Robert D. Television and aggression: An experimental field study. San Francisco: Jossey-Bass, 1971.
Foulkes, David, and Rechtschaffen. Allan. Pre sleep determinants of dream content: effects of two films. Perceptual and Motor Skills, 19(3): 983-1005, 1964.
Goldstein. Naomi Slutsky. The effect of animated cartoons on hostility in children. New York University, 1956. Dissertation Abstracts, 17: 1125. 1957.
Hartman, Donald P. Influence of symbolically modeled instrumental aggression and pain cues on aggressive behavior. Journal of Personality and Social Psychology, 11(3): 280-288, 1969.
Kuhn, Deanna Zipse, Madsen, Charles H. , Jr. , and Becher, Wesley C. Effects of exposure to an aggressive model and "frustration" on children's aggressive behavior. Child Development, 38(3): 739-745, 1967.
Larder, Diane L. Effects of aggressive story content on non-verbal play behavior. Psychological Reports, 11: 14, 1962.
Lovaas, O. Ivar. Effect of exposure to symbolic aggression on aggressive behavior. Child Development, 32: 37-44, 1961.
Maccoby, Eleanor E. , Levin, Harry, and Selya, Bruce M. The effects of emotional arousal on the retention of aggressive and nonaggressive movie content. American Psychologist, 10(8): 359, 1955.
Maccoby, Eleanor E. , Levin, Harry, and Selya, Bruce M. The effects of emotional arousal on the retention of film content: a failure to replicate. Journal of Abnormal and Social Psychology, 53(3): 373-374, 1956.
Maccoby, Elearnor E. , and Wilson, William Cody. Identification and observational learning from films. Journal of Abnormal and Social Psychology. 55: 75-87, 1957.
Meyerson, Leonard Jack. The effects of filmed aggression on the aggressive responses of high and low aggressive subjects. University of Iowa, 1966. Dissertation Abstracts, 27, 3291-B, 1967.
Mussen, Paul. and Rutherford, Eldred. Effects of aggressive cartoons oil children's aggressive play. Journal of Abnormal and Social Psychology, 62(2): 461-464, 1961.
Siegel, Alberta Engvall. Film-mediated fantasy aggression and strength of aggressive drive. Child Development, 27: 365-378, 1956.
YOUNG ADULTSBerkowitz, Leonard, Corwin, Ronald, and Heironimus, Mark. Film violence and subsequent aggressive tendencies. Public Opinion Quarterly, 27: 217-229, 1963.
Berkowitz, Leonard, and Geen, Russell G. Film violence and the cue properties of available targets. Journal of Personality and Social Psychology, 3(5): 525-530, 1966.
Berkowitz, Leonard, and Geen, Russell G. Stimulus qualities of the target of aggression: a further study. Journal of Personality and Social Psychology, 3(5): 525-530, 1966.
Berkowitz, Leonard, and Geen, Russell G. Stimulus qualities of the target of aggression: a further study. Journal of Personality and Social Psychology, 5(3): 364-368, 1967.
Berkowitz, Leonard, and Rawlings, Edna. Effects of film violence on inhibitions against subsequent aggression. Journal of Abnormal and Social Psychology, 66(3): 405-412, 1963.
Bokander, Ingvar, and Lindbom, Kerstin. The effects of aggressive films on minors. Nordisk Psykologi, 19(1): 1-56, 1967.
Feshbach, Seymour. The drive reducing function of fantasy behavior. Journal of Abnormal and Social Psychology, 60(1): 3-11, 1955.
Feshbach, Seymour. The stimulating versus cathartic effects of a vicarious aggressive activity. Journal of Abnormal and Social Psychology, (63)(2): 381-385, 1961.
Geen, Russell G. Effects of frustration, attack, and prior training in aggressiveness upon aggressive behavior. Journal of Personality and Social Psychology, 9(4): 316-321, 1968.
Geen, Russell G. , and Berkowitz, Leonard. Name-mediating aggressive cue properties. Journal of Personality, 34: 456-465, 1966.
Geen, Russell G. , and Berkowitz, Leonard. Some conditions facilitating the occurrence of aggression after the observation of violence. Journal of Personality, 35: 66-676, 1967.
Kaufman, Harry, and Feshbach, Seymour. The influence of antiaggressive communications upon the response to provocation. Journal of Personality, 31(3): 428-444, 1963.
Lefcourt, Herbert M. , Barnes, Keith, Parke, Ross, and Schwartz, Fred. Anticipated social censure and aggression-conflict as mediators of response to aggression induction. Journal of Social Psychology, 70: 251-263, 1966.
Walters, Richard H. , and Llewellyn-Thomas, Edward. Enhancement of punitiveness by visual and audiovisual displays. Canadian Journal of Psychology, 17: 244-255, 1963.
Walters, Richard H. , Llewellyn-Thomas, Edward, and Acker, C. William. Enhancement of punitive behavior by audiovisual displays. Science, 136(3519): 872-873, 1962.
Appendix E: The Interpretation of Correlation CoefficientsThe Pearson product moment correlation coefficient is an abstract statistic which, under certain restrictive conditions, precisely describes the relationship between two variables. Although the restrictive conditions or "assumptions" underlying the application of the correlation coefficient (norm al distributions in both variables, strict linearity of regression, stratified random sampling in one of the variables, and homoscedasticity or equal variance in the arrays) are seldom if ever met in practice, the correlation coefficient is widely used -- albeit with a grain of salt -- as a crude indicator of a relationship.
Many misunderstandings arise from what appears to be a general tendency to misinterpret or overinterpret correlation coefficients.
At certain levels, there can be no mistake in interpretation. A correlation coefficient of 1. 0 means unequivocally that, as the value of one variable increases, the value of the other variable increases proportionately; a correlation coefficient of - 1. 0 means that increase in one variable is accompanied by proportionate decrease in the other. A value of 0. 0 clearly means that there is no linear relationship between the two variables.
But what about the cases where the correlation coefficient is in some middle range, like the . 30 relationships which stand out from the mass of trivial relationships reported in these studies? If, indeed, the assumptions listed above are met, one can still say that, as one variable increases in value, the mean value of the other variable increases, although at each level of the first variable, there is considerable variation around the mean of the second variable. Furthermore, if the assumptions are not met (as in many of the correlation coefficients in these studies), such a bland statement of a functional relationship is clearly misleading. Thus, if the requirements for linearity and homoscedasticity are not met, two important pitfalls await the unwary interpreter of correlation coefficients:
(1) The functional relationship may exist strongly in one or more parts of the range of the variables, but not in other parts of the range.
(2) Frequently, the locus of the relationship is at the very top or very bottom of the range in both variables, so that a relatively small number of outlying cases may produce a relationship which exists nowhere else.
Statisticians universally advise users of summary statistic, s to examine the data. In the use of correlation coefficients, such advice calls for examination of bivariate distributions or scatter diagrams.
Figure E-1: Linear, homoscedasticFigures E-1 through E-4 illustrate, in a highly stylized way, the variety of data configurations that can lead to approximately equal correlation coefficients. In each figure, each dot represents an individual case; the solid line represents the least-squares regression line. We have not attempted to make these figures precise, nor to use real data. Adjustment of scale and frequencies can modify the size of the correlation coefficients. Nevertheless, comparison of the four figures will indicate that similar correlation coefficients can summarize different situations which vary markedly in regard to the actual overall relationship between two variables among a group of individuals.
Figure E-2: Linear, heteroscedasticFigure E-3: Non-linear, homoscedasticVariance accountabilityThe square of the correlation coefficient is legitimately interpreted as the "proportion of variance accounted for." This powerful-sounding accomplishment is perhaps even more widely misapplied and misunderstood than the correlation coefficient itself. Each of the component variables is characterized by a "variance" -- i. e. , an abstract indicator of dispersion of values around the mean of the variable. If certain conditions (homoscedasticity and linearity) are met, and if the correlation coefficient is greater than zero, then, for any given value of one of the variables. the associated values of the other variable will cluster more closely around their mean (i. e. , have less variance) than the original variance of the second variable. The proportionate reduction in variance thus achieved. is the "variance accounted for. " Thus a correlation coefficient of . 30 would lead to the statement that nine percent of the variance in each variable is accounted for by variation in the other. This phenomenon is sometimes popularly phrased in terms of improvement over chance in the ability to guess at the value of one of the variables. given knowledge of the value of the other. Of course, if the specified conditions do not apply (as in Figures E-2 through E-4), then the proportion of variance accounted for is an average across the range of the two variables and may be higher in certain parts of the range and lower in others.
Figure E4: Non-linear, heteroscedasticChance and unreliabilityIn dealing with a mass of reported summary statistics, as this committee has tried to do, two opposing kinds of criticism are likely to be heard:
(1) With so many correlation coefficients being reported on the relationship of television exposure and aggressive tendencies, some few of them will turn out to be significant by chance alone. Indeed, the results here reviewed include a distribution of values for correlation coefficients all purporting to be of operational measures of the same underlying variables. The majority of the values are trivially small, but the central tendency of the values is clearly positive. En masse, they indicate a small positive relationship between amount of violence viewing and aggressive behavior. We have paid particular attention to the few larger correlation values, because it is reasonable to assume that some specific quality of the measures used accounts for the stronger relationship found. But. ultimately, only replication will establish whether the stronger relationships derive from such characteristics of the measures or whether they are products of chance.
(2) Since the measures used in these relationships are not highly reliable (in a psychometric sense), the observed relationships among them are likely to be underestimates of the "true" relationships between the concepts. This, too. is an untestable assertion, since, both for sampling reasons and for reliability reasons, any observed relationship may be either an underestimate or an overestimate of a "true" relationship. In particular, if the "true relationship is 0. 0, the probability that an observed relationship is an underestimate is exactly equal to the probability that it is an overestimate. On the other hand, if the "true" relationship is positive, then the probability that an observed relationship will, because of unreliability, be an underestimate is larger than the probability that it will be an overestimate. In the absence of knowledge about the nature of the "true" relationship, any conclusions on this point would be technically unjustified. If we were to assume that the mass of data would lead us to the conclusion that, in truth, there is a low positive relationship between the concepts under consideration, we could say that because of unreliability, the possibility that we are reporting underestimates is very slightly higher than the probability that we are reporting overestimates.
U. S. GOVERNMENT PRINTING OFFICE, 1972 120-717/633 DHEW Publication No. HSM 72-9090 Printed 1972 U. S. DEPARTMENT OF HEALTH, EDUCATION. AND WELFARE Health Services and Mental Health Administration National Institute of Mental Health.
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Notes: Appendix A1. The National Association of Educational Broadcasters conducted surveys of television content in Los Angeles (May 23-29, 1951), New York (January 4-10, 1951, 1952, 1953, January 25-31, 1954), New Haven (May 15-21, 1952, and Chicago (July 30-August 5, 1951).
2. U. S. Senate Committee on the Judiciary, Investigation of Juvenile Delinquency in the United States, Television and juvenile delinquency, 84th Congress, 2d session, January 16, 1956. Report No. 1466.
3. U. S. Senate Committee on the Judiciary, Effects on young people of violence and crime portrayed on television, Part 16 of Investigation of Juvenile Delinquency in the United States, July 30, 1964, p. 3731
4. National Commission on the Causes and Prevention of Violence. Commission Statement on Violence in Television Entertainment Programs, September 23, 1969.