Introduction and Overview
Abstract and Keywords
The study of social influence has been central to social psychology since its inception. In fact, research on social influence began in the 1880s, predating the coining of the term social psychology. However, by the mid-1980s, interest in this area had waned. Now the pendulum is swinging back, as seen in growing interest in non-cognitive, motivational accounts. Our hope is that the publication of this volume will aid this movement. The chapters, written by leading scholars, cover a variety of topics in social influence, incorporating a range of levels of analysis (intrapersonal, interpersonal, and intragroup) and both source and target effects. The book also includes chapters on theories that are most relevant to social influence, as well as a set of chapters on social influence in applied settings. Finally, we include a section that considers the future of social influence in social psychology.
Social influence lies at the heart of social psychology. In fact, in his classic Handbook chapter, E. E. Jones (1985) noted that social psychology “can almost be defined as the study of social influence” (1985, p. 79). If anything, this is an understatement, as is shown by a comparison of their definitions. Social influence has been defined as the process “wherein one person’s attitudes, cognitions, or behaviors are changed through the doings of another” (Cialdini & Griskevicius, 2010, p. 385) and as “the myriad ways that people impact one another, including changes in attitudes, beliefs, feelings and behavior, that result from the comments, actions, or even the mere presence of others” (Gilovich, Keltner, & Nisbett, 2011, p. 276). Social psychology has been defined as “an attempt to understand and explain how the thought, feeling, and behavior of individuals are influenced by the actual, imagined, or implied presence of other human beings” (Allport, 1954, p. 3, italics in original).
The fact that the first experimental work in what would come to be termed “social psychology” (Allport, 1924) was conducted on topics that would later be placed under the rubric of social influence also demonstrates the crucial role that it has played in the history of social psychology. For example, Binet and Henri’s (1894, as cited by Prislin & Crano, 2012) research on suggestibility prefigured Asch’s (1951) work on conformity. Féré (1887, as cited by Prislin & Crano, 2012) and Triplett (1898) examined a phenomenon that Allport (1924) would later term “social facilitation.” In the 1880s, Ringelmann conducted research on the effect of working with others (published in 1913, as cited by Kravitz & Martin, 1986), which was later extended in work on social loafing (Latané, Williams, & Harkins, 1979).
Given the centrality of social influence in the field, it would be no exaggeration to say that virtually any topic in social psychology, aside, perhaps, from hard-core social cognition, could be included in a handbook of social influence. Certainly there are some topics that form the core of social influence, such as conformity (e.g., Asch, 1951), (p. 4) compliance (e.g., Freedman & Fraser, 1966), and obedience (e.g., Milgram, 1963) that would be included in any such volume. Work in these areas exhibits many of the hallmarks of research on social influence: a high degree of experimental realism; behavioral measures; and real-world settings. As can be seen from the dates of these citations, work in these areas predates the cognitive revolution, and interest in these areas continues to the present day, even in the popular media, as is suggested by the recent release of two films, The Experimenter (2015), which depicts Milgram’s obedience research, and The Experiment (2015), which portrays Zimbardo’s prison simulation.
On the other hand, there are other topics that likely would not be included, even though they obviously involve social influence. For example, persuasion clearly represents a means of social influence, but it is typically not included under the rubric of social influence. In fact, research on social influence and attitudes is not even published in the same subsections of the top journal of the field, the Journal of Personality and Social Psychology. Research on persuasion is published in the Attitudes and Social Cognition section, whereas research on social influence is published in Interpersonal Relations and Group Processes.
Prislin and Crano (2012) argue that in the early part of the 20th century, likely as a result of the theoretical influence of people like Dewey (1922/1930) and Mead (1934), attitudes were thought of in terms of group-shared norms. However, they argue that this orientation ran afoul of efforts by psychologists such as Floyd Allport (1919, 1924) to “establish social psychology as a science that uses the individual as a unit of analysis” (p. 332), and “consequently, attitudes were defined in strictly individualistic terms without reference to social influence” (p. 333). Prislin and Crano argue that the domination of the field for the past 50 years by the cognitive orientation has reinforced this divorce of attitudes from social influence.
In addition, persuasion research also tends to use paper-and-pencil paradigms (or, more appropriately in this era, computer-presented paradigms) in laboratories that allow for the measurement of intervening processes. These measures can then be used to assess mediation, the testing of which has been de rigeur in social psychology for the last several decades. Field studies, however, which account for many studies in social influence, are not amenable to the use of intervening, intrusive questionnaires aimed at assessing possible mediation. In this sense, classic social influence methods have fallen out of favor in our field, possibly further separating persuasion research and theory from social influence research and theory.
Although these arguments have merit, there may be a simpler explanation. In his 1935 Handbook chapter, Gordon Allport noted that “the concept of attitude is probably the most distinctive and indispensable concept in contemporary American social psychology” (p. 798), and, in the 1954 Handbook, he noted that the construct of attitude is the “primary building stone in the edifice of social psychology” (p. 63). Perhaps the sheer volume of work on attitudes and its centrality to the field require that it stand alone. Certainly it would be hard to argue that persuasion is not a form of social influence.
In any event, in the current volume we follow historical precedent and devote chapters to topics such as conformity, compliance, and obedience, but we will not include a chapter on persuasion. In fact, consistent with the earlier argument, a treatment of attitudes and attitude change would easily be worth a volume of its own. For the rest of the chapters, we have selected a range of topics that fall under the rubric of social influence. Unlike some reviews that include only research that focuses on the target of social influence attempts (e.g., Cialdini & Trost, 1998), we also include some chapters that focus on influence sources—their motivation and differential effectiveness. The chapters incorporate a range of levels of analysis: intrapersonal, interpersonal, and intragroup. We include two chapters that cover the theories most relevant to social influence effects: social comparison and social identity. We have also included a set of chapters that examine social influence effects in applied settings. Finally, we include a section that considers the future of social influence in social psychology.
We begin with a chapter that covers ethical issues in social influence research from Milgram’s work in the 1960s, the conduct of which, at the least, served to increase concern about ethical behavior in research, through current work conducted on the Internet (Kimmel). We then move to a pair of chapters on Intrapersonal Processes, one on gender and one on personality. In her chapter, Carli compares females and males both as sources and targets of influence. However, as will be seen, although gender differences in influenceability were reported in the 1980s (e.g., Eagly & Carli, 1981), current research shows little evidence of overall differences. (p. 5) The same is not true for gender differences in source effects: Women are less effective sources of social influence than men. Carli provides evidence for this claim and suggests reasons for it.
Nezlek and Smith’s chapter is devoted to the intersection of personality and individual differences with research and theory on social influence. Strangely, the two domains have not enjoyed much overlap; so in addition to covering the existing research in which researchers ask what traits are associated with influence and influenceability, Nezlek and Smith speculate as to why the two areas are not highly interwoven, and they implore future researchers to consider their mutual interaction.
In the next section of the volume we look at social influence as it is reflected in interpersonal processes. We begin with a chapter in which Suls and Wheeler review the development of social comparison theory. We do not mean to suggest that social comparison theory (Festinger, 1954) is directly relevant to all of the chapters in this section, but it was a dominant theory in the period of time in which much of the work in this section was begun, and it helped to shape the thinking in this period. For example, the distinction between normative and informational influence in conformity that was made by Deutsch and Gerard (1955) echoes the two aims of social comparison: self-enhancement and self-evaluation. Normative influence stems from our concern about how we appear to others. People want their opinions, beliefs, and attributes to reflect positively on themselves (self-enhancement), but they are also motivated to learn the truth, as is reflected by the effect of informational influence (self-evaluation).
In the next chapters in this section, we cover conformity, compliance, and obedience. We present these topics in this order because this organization reflects an underlying dimension of social control that begins with behavior that is produced by the simple observation of others engaging in the target behavior (conformity), then goes to behavior that is produced by requests (compliance), and ends with behavior that is produced by the orders or demands of someone in authority (obedience).
In his chapter, Hodges describes conformity as a crucial dimension of culture and of human survival. Without it, we would not have survived. However, Hodges argues that equally important is the fact that people have a tendency to diverge. Hodges proposes that traditional experimental social psychology has focused on the former without giving enough weight to the latter. Hodges also argues that experimental social psychology has focused too much on the molecular level of behavior without situating this behavior in the larger cultural context. In his chapter, he incorporates work from anthropology, as well as social, developmental, and cognitive psychology, arguing for a broader view of the complex interplay of conformity and divergence.
In Guadagno’s chapter on compliance, she focuses primarily on how social influence tactics influence others to change their behavior. To many, this focus comprises the core of social influence—a preponderance of field studies in which individuals buy products, commit time, sign petitions, erect posters, or vote, for things, people, and ideas that they were unlikely to buy or endorse before. Relying on Cialdini’s (2009) six principles of influence—reciprocity, commitment and consistency, authority, social validation or social proof, and liking and similarity—she organizes her chapter around an examination of the extant research on these six principles, their underlying mechanisms, especially the mindlessness hypothesis, and their application to influence within the newest realm of social influence: social media.
In his chapter, Burger reviews research on how individuals respond to orders or demands from a person or institution in a position of authority. Although there has been some other work, for more than 50 years, research and discussion in this area have been dominated by Milgram’s work on destructive obedience. In fact, it would be hard to find any other topic in social influence in which a single program of research has exerted so much influence on the work on that topic dating from its inception to the present. This is particularly surprising given that Milgram’s interpretation of his own findings did not find wide acceptance even at the time that it was proposed. Burger provides an account of the development of this area of research and provides suggestions as to how it can move beyond Milgram’s pioneering work.
In the next chapter, Nolan discusses social norms as a source of social influence. Although social norms and conformity are closely related topics, there is a key difference. In his chapter on conformity, Hodges notes that conformity is nearly always understood in terms of matching one’s behavior with that of others because one observed others engaging in that behavior. In her chapter, Nolan defines social norms as “rules and standards that are understood by members of a group, and that guide morally relevant social behavior by way of social sanctions, instead of the force of laws.” Thus, although closely (p. 6) related to conformity, social norms can operate without direct observation of others engaging in the target behavior. In her chapter, Nolan argues that her perspective represents a new way of looking at social norms that emphasizes norm enforcement as an essential component of understanding and defining a behavior as normative. Thus, in addition to the typical review of the literature on social norms as sources of social influence, the chapter discusses how and when individuals enforce norms. Nolan also discusses methods of maximizing the effects of social norm interventions, paying particular attention to combining descriptive and injunctive norms, reference groups, personal relevance, and cognitive resources.
McCarty and Karau define social inhibition as the tendency for behaviors that are typically exhibited to be minimized in the presence of others. In some ways, social inhibition is similar to conformity, in that there need be no intention to influence on the part of the sources: simple awareness of (or belief in) their presence is sufficient to lead to the cessation of the target’s behavior. McCarty and Karau argue that, despite its long history, research on social inhibition does not form a cohesive literature. In their chapter, they address this issue by integrating research from several different traditions, including helping behavior, emotional expression, and behaviors that elicit social disapproval. They go on to discuss moderators and mediators of these effects (e.g., arousal, ambiguity, pluralistic ignorance, diffusion of responsibility, feelings of capability, evaluation apprehension, and confusion of responsibility), and to distinguish social inhibition from other related concepts. By so doing, they hope to facilitate the integration of future research on this topic.
In their chapter on social facilitation, Seitchik, Brown, and Harkins note that research conducted for more than a century has shown that the presence of others improves performance on simple tasks and debilitates it on complex tasks, whether these others are audience members or coactors. In their chapter, Seitchik et al. review theories offered to account for how two features of these others, their mere presence and/or the potential for evaluation they represent, produce these effects, and they conclude that we are no closer now to isolating the relevant process(es) than we were 100 years ago. They then consider the molecular task analysis proposed by Harkins (2006) as an approach to attacking this problem, followed by a review of the work testing the mere effort account suggested by this analysis. Finally, they place the mere effort account in the larger context represented by the threat-induced potentiation of prepotent responses model, which aims to account for the effect of threat on task performance. Seitchik et al. argue that this approach shows great promise, having the potential to integrate the different lines of research that focus on motivated task performance, such as social loafing, goal setting, intrinsic motivation/creativity, achievement goal theory, social facilitation, and stereotype threat.
Hales, Ren, and Williams’s chapter examines the universal phenomenon of ostracism—ignoring and excluding—and how it works to guide and influence behavior. A relative newcomer on the social influence research block, this chapter summarizes over 20 years of social psychological research that demonstrates ostracism’s power. The authors argue that ostracism—or the threat of it—serves to account for the potency of normative influence. Targets of ostracism experience pain, threatened fundamental needs, and worsened mood. As a consequence, they think and act in ways to fortify their threatened needs, including going along to get along, lashing out, and seeking solitude. The authors also review the research on what motivates sources to use ostracism, as well as examining the impact of ostracizing on the sources who use it. The sources’ motives are tied to the functions they think ostracism serves. The authors propose three functions of ostracism: (1) to protect—shielding groups from threatening members; (2) to correct—signaling to individuals that their behavior needs to be modified to remain in the group; and (3) to eject—permanently removing deviant individuals who resist correction.
In a chapter that focuses on source effects, Tyler and Adams consider self-presentation as a social influence tactic. They suggest that past research has characterized people’s self-presentations as resulting from conscious and deliberate strategic efforts to influence the impressions that others form of them, and note that this approach results in both theoretical and empirical problems. For example, following this approach has limited the research designs that have been used, thereby ignoring the issue of context cuing. Tyler and Adams argue that the results of the few studies that have examined automatic self-presentation are promising, and they provide the foundation for future work.
In his chapter, Van Kleef examines the interpersonal, rather than the intrapersonal, effects of emotional expression. That is, in contrast to the existing models that focus on the effects that a (p. 7) person’s emotions has on him/herself, Van Kleef’s theory (emotions as agents of social influence theory) focuses on the effects that one person’s emotional expressions has on another person’s attitudes, cognitions, and/or behavior. Van Kleef proposes a dual process model, which suggests that emotional expressions can exert social influence through an inferential process or through affective reactions. The inferential pathway is used to the extent that the target is motivated and able to engage in thorough information processing and perceives the emotional expression to be appropriate. To the extent that the target’s ability or motivation to process the information is reduced and s/he perceives the emotional expression as inappropriate, the affective pathway is used. Van Kleef goes on to discuss differences and commonalities between this interpersonal framework and the more traditional intrapersonal approach.
In the next section of the volume we look at social influence processes as an intragroup process. In their chapter on social identity/self-categorization processes, Gaffney and Hogg note that, traditionally, social psychologists have examined social influence processes at an interpersonal level, focusing on the relationship between the individual target and the individual source. However, influence can occur within a group context as well; as a result, accounting for group membership and group identification allows for a more comprehensive understanding of social influence. As was the case for social comparison theory, we do not mean to suggest that social identity/self-categorization is directly relevant to all of the chapters in this section, but it has been highly influential since the early 1990s. In their chapter, adopting a social identity/social categorization perspective, Gaffney and Hogg provide an overview of group-based motivations for influence, including leadership, minority group influence, and political and social movements as examples of social influence taking place in a group context. In later chapters in this section, some of these topics are examined in greater detail (e.g., leadership, minority influence). The Gaffney and Hogg chapter provides an overall context into which these treatments can be placed.
In his chapter on deindividuation, Spears argues that this phenomenon occupies a central place in social influence’s pantheon. However, he notes that deindividuation theory’s central premise that people lose their sense of self in the group, becoming more likely to engage in mindless aggression, has not received consistent support over the years. In his chapter, Spears makes the case for a social identity account of crowd behavior—that the individual self gives way to the social self; but he also points out that techniques for tapping unconscious states and processes that are now available also provide the opportunity to test the original predictions in more compelling ways than were possible when the original research was conducted.
Hornsey and Jetten, in their chapter on stability and change within groups, examine the psychological tension produced by defending the status quo within groups and engaging in intragroup change. They begin with the same foundational research on conformity covered elsewhere in this volume (e.g., Hodges), but they extend their analysis to the processes at work in interacting groups. They then go on to provide a counterpoint to the analysis that emphasizes pressures toward stability by showing that intragroup change and reform is also an integral part of group life. Finally, they examine the process of change within the group: who is most likely to seek it; who is more effective at seeking it; and what strategies are most effective in producing it.
The next chapter, by Butera, Falomir-Pichastor, Mugny, and Quiamzade, also covers minority influence, but it sets out to explain the ways in which minority points of view may, or may not, influence society at large. Whereas social influence research in the United States tended to focus on the power of majorities, European research reflected their experiences with the power of a persistent minority in effecting important changes. The authors examine the early findings of Moscovici, Nemeth, and others, as well as the critiques leveled against these groundbreaking studies. Always present was a tension between points of view that saw minority influence as derivative of, or qualitatively different from, majority influence. Newer models have sparked a great deal of research that makes this particular topic a lively and growing domain within social influence.
Adopting a social identity perspective, Platow, Haslam, and Reicher propose that leadership, the process of enhancing the contribution of group members to the realization of group goals, essentially represents group-based social influence, emerging from psychological in-group members, particularly highly in-group prototypical ones. The authors argue for a difference between failed and successful leadership, not so much in terms of influence, but in terms of the source of influence. Power over resources can allow a leader to control the behavior of followers, but this is a sign of failed leadership, because in these instances behavior is geared (p. 8) toward gaining reward and avoiding punishment, rather than pursuing a collective vision. Successful leadership depends upon shared social identity, and it is conferred on would-be leaders as much as created by the leaders themselves. This differentiation between successful and failed leadership provides insight into examining research, theory, and application of leadership processes and outcomes.
In the next section of this volume, we include chapters that describe the use of social influence techniques in four applied fields: clinical psychology, health, law, and consumer behavior.
Heesacker organizes his chapter on social influence and clinical intervention using Kelman’s (1958) tripartite model: compliance, identification, and internalization. In this model, compliance is not defined as behavior in accord with a request, but rather as cooperation motivated by the desire for social acceptance. People are influenced to comply because they wish to avoid negative social consequences or to gain social approval. Heesacker’s review suggests that under some circumstances, normative feedback has changed behaviors like drug abuse and gambling. Of course, this work is directly relevant to the work on social norms described by Nolan in her chapter of that name in the current volume, as well as Hodges’s chapter on conformity. The second process, identification, is relevant for understanding the effect of the therapeutic alliance between the therapist and client. This alliance strengthens the extent to which the client identifies with the therapist, which Heesacker argues is causally related to clinical outcomes. Finally, Heesacker argues that although a great deal of basic social influence research has been conducted on internalization, this work has had little influence on clinical practice. Much more research has been generated by a clinician-developed approach to internalization: motivated interviewing. Heesacker then bemoans the lack of basic social influence research relevant to clinical practice produced in recent years and describes a number of promising directions that this research could take.
In their chapter on social influence and health, Martin and DiMatteo examine the effects of different sources of social influence on health behavior: parents; peers once one enters adolescence; social networks as one enters adulthood; health care providers; and system-level influences like public health programs, health-related media messages, and educational interventions. Social comparison processes (Suls & Wheeler, this volume), supportive social networks, and social norms (Nolan, this volume) serve as sources of these effects.
In their review, Demaine and Cialdini conceptualize social influence and the law as consisting of three parts: social influence in the legal system; the legal regulation of social influence in our everyday lives; and law as an instrument of social influence. Their review suggests that most psychological research has focused on the first part. For example, the suggestibility of eyewitnesses recounting events underlying litigation and false confessions by crime suspects resulting from police interrogations have each benefitted from long-term, programmatic study, as have several facets of juror decision making. In contrast, the study of the effects of legal regulation of social influence in our everyday lives has received sparse and scattershot attention, as has the third part, law as an instrument of social influence. Demaine and Cialdini argue that the lopsidedness of the attention paid to the three areas does not reflect the importance of or differences in the number of empirical questions in these domains, and that these neglected areas hold great promise for future inquiry.
Kirmani and Ferraro tackle the burgeoning research on social influence in marketing. Marketing and consumer behavior are a perfect fit for social influence because the ultimate goals are behavioral: purchases for self and others, and telling others of their purchases and evaluations of the products. Truly one of the domains in which social influence research has accelerated, the authors focus their review on the research published only in the top journals in marketing and consumer behavior. Recognizing that the research on social influence in marketing borrows from many other disciplines, Kirmani and Ferraro nicely weave theory and research from social psychology, economics, sociology, anthropology, and communication into the field of marketing. The authors also point to some groundbreaking research by consumer researchers—gift giving and word of mouth—that will provide theory and be of interest to these other fields.
In the final section, informed by the chapters of the volume, we speculate about the future of research and theory in social influence. We also include two final chapters: Sagarin and Henningsen’s chapter focuses on resistance to persuasion and shows how this research can help to shape the future work that will be required to understand resistance to behavioral social influence attempts; and, in recognition of the profound changes coming to the study of social influence, the final chapter, by David Byrne (p. 9) of the Talking Heads, provides an example of how social media can affect the social influence process.
Allport, F. H. (1919). Behavior and experiment in social psychology. Journal of Abnormal Social Psychology, 67, 326–333.Find this resource:
Allport, F. H. (1924). Social psychology. New York, NY: Houghton Mifflin.Find this resource:
Allport, G. (1935). Attitudes. In C. Murchison (Ed.), Handbook of social psychology (pp. 798–844). Worcester, MA: Clark University Press.Find this resource:
Allport, G. (1954). The historical background of modern social psychology. In G. Lindzey (Ed.), Handbook of social psychology (Vol. 1, pp. 3–56). Cambridge, MA: Addison Wesley.Find this resource:
Asch, S. (1951). Effects of group pressure upon the modification and distortion of judgments. In H. Guetzkow (Ed.), Groups, leadership, and men (pp. 177–190). Pittsburgh, PA: Carnegie Press.Find this resource:
Binet, A., & Henri, V. (1894). De la suggestibilité naturelle. Revue Philosophique, 38, 337–348.Find this resource:
Cialdini, R. B. (2009). Influence: Science and practice (5th ed.). Boston, MA: Allyn & Bacon.Find this resource:
Cialdini, R. B., & Griskevicius, V. (2010). Social influence. In R. F. Baumeister & E. J. Finkel (Eds.), Advanced social psychology (pp. 385–417). New York, NY: Oxford University Press.Find this resource:
Cialdini, R. B., & Trost, M. R. (1998). Social influence: Social norms, conformity, and compliance. In D. T. Gilbert, S. T. Fiske, & G. Lindzey (Eds.), Handbook of social psychology (Vol. 2, pp. 151–192). New York, NY: McGraw-Hill.Find this resource:
Deutsch, M., & Gerard, H. B. (1955). A study of normative and informational social influences upon individual judgment. Journal of Abnormal and Social Psychology, 51, 629–636.Find this resource:
Dewey (1922/1930). Human nature and conduct: An introduction to social psychology. New York, NY: The Modern Library.Find this resource:
Eagly, A., & Carli, L. (1981). Sex of researchers and sex-typed communications as determinants of sex differences in influenceability: A meta-analysis of social influence studies. Psychological Bulletin, 90, 1–20.Find this resource:
Féré, C. (1887). Sensation et movement: Etudes experimentales de psycho-mécanique. Paris, France: Alcan.Find this resource:
Festinger, L. (1954). A theory of social comparison processes. Human Relations, 7, 117–140.Find this resource:
Freedman, J. L., & Fraser, S. C. (1966). Compliance without pressure: The foot-in-the-door technique. Journal of Personality and Social Psychology, 4, 195–202.Find this resource:
Gilovich, T, Keltner, D., & Nisbett, R. E. (2011). Social psychology. New York, NY: W. W. Norton & Company.Find this resource:
Harkins, S. G. (2006). Mere effort as the mediator of the evaluation-performance relationship. Journal of Personality and Social Psychology, 91, 436–455.Find this resource:
Jones, E. E. (1985). Major developments in social psychology during the past five decades. In G Lindzey & E. Aronson (Eds.), Handbook of social psychology (Vol. 1, pp. 47–107). New York, NY: Random House.Find this resource:
Kelman, H. C. (1958). Compliance, identification, and internalization: Three processes of attitude change. Public Opinion Quarterly, 2, 51–60.Find this resource:
Kravitz, D. A., & Martin, B. (1986). Ringelmann rediscovered: The original article. Journal of Personality and Social Psychology, 50, 936–941.Find this resource:
Latané, B., Williams, K. D., & Harkins, S. G. (1979). Many hands make light the work: The causes and consequences of social loafing. Journal of Personality and Social Psychology, 37, 822–832.Find this resource:
Mead, G. H. (1934). Mind, self, and society: From the standpoint of a social behaviorist. Chicago, IL: University of Chicago Press.Find this resource:
Milgram, S. (1963). Behavioral study of obedience. Journal of Abnormal and Social Psychology, 67, 371–378.Find this resource:
Prislin, R., & Crano, W. D. (2012). A history of social influence research. In A. Kruglanski & W. Stroebe (Eds.), Handbook of the history of social psychology, (pp. 321–339). New York, NY: Psychology Press.Find this resource:
Ringelmann, M. (1913). Recherches sur les moteurs animés: Travail de l’homme. Annales de l’Institut National Agronomique, 2e série—tome XIII, 1–40.Find this resource:
Triplett, N. (1898). The dynamogenic factors in pacemaking and competition. American Journal of Psychology, 9, 507–533. (p. 10) Find this resource: