Bibb Latané

The Psychology of Social Impact

The author proposes a theory of social im- pact specifying the effect of other persons on an in- dividual. According to the theory, when other people are the source of impact and the individual is the target, impact should be a multiplicative function of the strength, immediacy, and number of other people. Fur- thermore, impact should take the form of a power func- tion, with the marginal effect of the Nth other person being less than that of the (N — l)th. Finally, when other people stand with the individual as the target of forces from outside the group, impact should be divided such that the resultant is an inverse power function of the strength, immediacy, and number of persons stand- ing together. The author reviews relevant evidence from research on conformity and imitation, stage fright and embarrassment, news interest, bystander interven- tion, tipping, inquiring for Christ, productivity in groups, and crowding in rats. He also discusses the unresolved issues and desirable characteristics of the theory.

From Private Attitude to Public Opinion: A Dynamic Theory of Social Impact

A computer simulation modeled the change of attitudes in a population resulting from the interactive, reciprocal, and reeursive operation of Latan~s (198 I) theory of social impact, which specifies principles underlying how individuals are affected by their social environment. Surprisingly, several macrolevel phenomena emerged from the simple operation of this microlevei theory, including an incomplete polarization of opinions reaching a stable equilibrium, with coherent minority subgroups managing to exist near the margins of the whole population. Computer simulations, neglected in group dynamics for 20 years, may, as in modern physics, help determine the extent to which group-level phenomena result from individual-level processes. Writing about social phenomena, social scientists have produced empirical generalizations and theoretical analyses of social processes representing differing levels of social reality. Some analyses concern the cognitions, feelings, and behavior of individuals; others deal with small, medium, or large groups, collectivities, and organizations; still others involve such largescale human aggregates and systems as nations, societies, or cultures. Theories can be and are formulated and tested independently for phenomena at each of these levels, but one can also ask about the relations between mechanisms operating at different levels (Doise, 1986; Kenny, 1987; Nowak, 1976). These relations may be of two kinds. The functioning of higher level units (e.g., social groups) may be partly or completely determined and therefore explained by mechanisms known from theories describing phenomena at lower levels (e.g., human individuals). Alternatively, the functioning of lower level units (e.g., individuals) may be affected by the higher level units to which they belong. In other words, individuals in a given social context behave differently than they would outside that context. These relations, taken together, suggest that the interactive impact of individuals and their social context can result in the emergence of new regularities at the levels of both the individual

Identifiability as a deterrant to social loafing: Two cheering experiments.

Two experiments tested the extent to which the identifiability of ones individual output moderates social loafing—the reduction of individual efforts due to the social presence of others. In the first stage of Experiment 1, participants were asked to produce noise either alone, in groups of two and six, or in pseudogroups where the individuals actually shouted alone but believed that one or five other people were shouting with them. As in previous research, people exerted less effort when they thought that they were shouting in groups than when they shouted alone. In the second stage, the same people were led to believe that their outputs would be identifiable even when they cheered in groups. This manipulation eliminated social loafing. Experiment 2 demonstrated that when individual outputs are always identifiable (even in groups), people consistently exert high levels of effort, and if their outputs are never identifiable (even when alone), they consistently exert low levels of effort across all group sizes. In concert, these studies suggest that identifiability is an important mediator of social loafing.

The social impact of majorities and minorities.

Previous theorizing about social influence processes has led to the emergence of two research traditions, each focusing on only a subset of influence situations. Research on conformity looks at the influence of the majority on a passive minority, whereas research on innovation considers the influence of active minorities on a silent majority. In the present article, we review these two lines of research, as well as some recent evidence, from the perspective of a new theory of social impact. This theory views social influence as resulting from forces operating in a social force field and proposes that influence by either a majority or a minority will be a multiplicative function of the strength, immediacy, and number of its members. Social impact theory offers a general model of social influence processes that integrates previous theoretical formulations and empirical findings and accounts for the reciprocal influence of majorities and minorities. By viewing social influence as a unitary concept, social impact theory permits comparisons between conformity and innovation and predicts the relative magnitude of their effects.

Distance Matters: Physical Space and Social Impact

Studies of college students and citizens of south Florida, United States, students in Shanghai, China, and an international sample of social psychologists show that social influence, measured by the frequency of memorable interactions, is heavily determined by distance. In all three cases, although there was a great deal of interaction with distant persons, the relationship between distance and interaction frequency was well described by an inverse power function with a slope of approximately -1, consistent with the expectation that social impact is proportional to the inverse square of the distance separating two persons. This result confirms one principle from Latanes 1981 theory of social impact and helps explain the ability of opinion minorities to cluster and survive in the face of majority influence.

Social loafing: Allocating effort or taking it easy?

When asked to work both alone and in groups, people exert less effort in groups, a phenomenon we call “social loafing.” Either of two possible strategies could explain this outcome: an allocational strategy where people work as hard as they can overall but conserve their strength for individual trials where work is personally beneficial and a minimizing strategy where the primary motive is to “get by” with the least effort possible. However, an allocational strategy would lead participants who always work in groups to put out as much effort as participants who always work alone, since there is no need to husband strength. Two studies using a sound production task found social loafing even under these conditions, suggesting that allocational strategies are not prevalent. Social loafing seems to occur when people perform together in groups, regardless of whether or not they must also perform alone.

The Effects of Group Size on Cognitive Effort and Evaluation

Students rated a poem and an editorial believing that they alone were responsible, that they were one of four persons responsible, or that they were one of sixteen persons responsible for evaluating the communications. As predicted, group mem bers reported putting less effort into the assessment than indi viduals, and this diffusion of effort followed an inverse power function. In addition, individuals evaluated the communications more favorably than persons who thought they shared the evalu ation responsibility.

Cross-modality matches suggest anticipated stage fright a multiplicative power function of audience size and status

Subjects adjusted the sound pressure level of a 1,000-Hz tone or the luminance of a 10° target on a translucent screen to match their anticipated subjective tension in performing before audiences represented by 1–16 color slides of old or young males or females. Consistent with a new theory of social impact, “tension” was a multiplicative power function of the number texponent ≅ .6) of people in the audience and their ages, with older t37-year-old) audiences generating 2–3 times the tension of younger Iteen-age) audiences. Male audiences elicited 50%-40% more tension than females.

The emergence of a social representation of human rights via interpersonal communication: empirical evidence for the convergence of two theories

To test the common assumption that social representations originate in ordinary communication, ten 24-person groups of American college students exchanged messages for 2 1/2 weeks about six specific issues drawn from a 21-item questionnaire previously used by Clemence, Doise, & Lorenzi-Cioldi (1994) in a cross-cultural investigation on human rights. As expected, interpersonal communication led to increased spatial clustering (neighbors in social space became more similar) and enhanced correlations among these issues, leading to a more coherent factor structure of human rights conceptions. Clustering and correlation simultaneously illustrate the emergence of self-organization in social systems and are taken as evidence for the social origin of social representations. These findings show how Latanes Dynamic Social Impact Theory complements Moscovicis Social Representation Theory, providing a mechanism for understanding how and criteria for knowing when social representations arise from communication.

Dynamic Social Impact

In this chapter, I discuss several conceptions of simulation as a tool for doing social science and describe a specific approach, dynamic social impact theory, for understanding the self organization of society. I then discuss some ways in which simulation has and has not been useful in advancing this theory and compare it with leading examples of sucessful social science simulations based on approaches from statistical physics, microeconomics, and distributed artificial intelligence. I do this, not as a philosopher of science, a physicist, or a computer scientist expert in the logic or techniques of computer simulation. Instead I am a working social psychologist, writing about computer simulation from a user’s perspective. My kind of social psychology is not just a subfield of psychology but an interdisciplinary focus on the individual human being as both the nexus of cultural, social, historical, economic, political, and biological influences, and the agent for societal change. People are the eyes and the brains and the arms of society, which, I believe, must be seen as a complex, self-organizing system whose nature can be explored with the help of computer simulation.