What are the different forms of social influence? How have they been studied by psychologists?

Introduction
Social influence refers to the process where an individual adapts their behaviour, emotions, or opinions as a result of interaction with others (Raven 1965; Abrams & Hogg, 2011). From choosing which brand of washing powder to buy, to forming an opinion on political ideologies, we are susceptible and influenced by the individuals around us. This social phenomenon prevails in a variety of forms, and is central to social interaction, personal identity, and in the determination of individual action. Forgas and Williams (2001) refer to social influence as the currency of social life, functioning at cognitive, interpersonal and cultural levels.
Cialdini and Goldstein (2003) propose that in the human drive for accuracy, affiliation, and maintenance of a positive self-concept, we open ourselves to the influence of society and those around us. Influence takes several forms, each of which can affect psychological change in a particular way (Myers, 2008). The concepts of conformity, compliance and obedience are frequently used to depict the effects of social influence on human behaviour (Gudjonsson & Sigurdsson, 2003). These follow a continuum of coercion, with conformity requiring less coercion, and obedience the most (Ferguson, 2004).

Conformity occurs when an individual aligns their behaviour, attitudes or beliefs to the implicit ideology or rules shared by the group (Hogg, & Vaughan, 2005).
Conforming to such group norms may occur with little conscious input, such as joining the back of a queue in a busy airport, or as a result of explicit social pressures, for example, an adolescent drinking an unpleasant alcoholic drink being passed around at a party. These examples also serve to demonstrate the qualitative distinction between normative and informational social influence. Normative influence is any influence where an individual conforms to the positive expectation of another, and informational influence is defined as the accepting of information obtained from another as evidence about reality (Deutsch & Gerard, 1955). Deutsch and Gerard (1955) offer further clarification, stating that normative conformity results from conflict between the wish to say what we think is correct and the fear of being socially rejected, whereas informational conformity results from conflict between what we observe and what we think. Crucially, both of these influences lead to a change in an individual’s behaviour or beliefs.
A seminal research experiment into conformity was conducted by Asch (1951), who investigated the effect of majority influence in changing the opinion of individuals. Participants met with six confederates and were given a line judgement task. In the task, they were shown a card depicting a vertical line, followed by a card with three vertical lines differing in length. The task was to select which of the three subsequent lines was the same length as the original. There was always a clear right answer. The confederates answered before the participant, unanimously selecting the wrong line on 12 out of 18 trials. Asch discovered that, compared to a control group in which only one of the participants ever gave a wrong answer, 75% of participants responded with an incorrect answer when following the incorrect confederates. This experiment demonstrated the power of majority influence on the behaviour and beliefs of individuals and supports the notion of normative influence, where participants’ wish to be socially accepted overpowered their knowledge of the correct answer. Without any active pressure or coercion, individuals conformed to the view of others. Asch (1951) found that increasing the size of the majority led to increased conformity, however maximal effect was reached with four people. It was proposed that the motivation for conformity was either ‘to avoid ridicule’ or because participants actually believed the confederates answers, however, it may be that participants were actually motivated to avoid conflict. Extensions in conformity research have shown that women tend to conform more readily than men, and that age and status act as influential characteristics (Eagly & Chrvala, 1986).
From influencing whether we buy a certain product to ensuring law abidance, adapting behaviours to adhere to the requests of others is integral to civilisation. The submission of an individual to the request of another, either directly or indirectly is referred to as compliance. Kelman (1958) distinguishes compliance from other forms of social influence, stating that the individual adopts a certain behaviour, however does not believe in its content, rather wishes to gain a certain reward or approval, or avoid punishment. Whilst other forms of social influence may produce identical overt behaviour, the underlying process of compliance is distinct in that the behavioural change occurs for social effect (Kelman, 1958).
Early research into compliance emphasised the role of external pressure and coercion on the likelihood of agreement. Kelman and Hovland (1953) discovered that influencers with higher credibility and prestige were more persuasive and received greater compliance. Other research investigated the role of discrepancy between the individual’s original opinion and the position required by the influencer in yielding attitude change (Hovland & Pritzker, 1957). Freedman and Fraser (1966) postulated that in addition to external pressures, there are other factors at work that can be harnessed to produce maximal compliance. In an influential paper, the authors demonstrated the power of the foot-in-the-door technique, in which an individual makes a small request, and having received initial compliance, subsequently makes a larger related request. Results showed that participants were twice as likely to comply with a large request having complied with a small request beforehand. Explanations of the foot-in-the-door technique’s effectiveness have centred on the notion of involvement, however, it was also recognised that once an individual has complied, a shift in attitude and self-concept may occur, meaning they become more compliant to future requests (Freedman & Fraser, 1966).
Obedience lies at the far end of the coercion continuum, where authority figures exert specific behaviour from an individual in response to direct instruction. The social consequences of obedience can be seen throughout societies, from the mass slaughtering of Cambodians by Khmer Rouge obeying Pol Pot’s regime, to the child avoiding the path of a passing car by obeying their parent’s order to “STOP!”. Milgram (1963) purports obedience to be “as basic an element in the structure of social life as one can point to”. This primitive, and possibly ingrained behaviour was illustrated by a widely cited and controversial experiment by Milgram (1963). Participants were given the role of ‘teacher’, and on the premise that the study was investigating the effects of punishment, were to administer electric shocks to ‘learner’ participants (confederates) when they gave an incorrect answer in a task. The teacher was to increase the voltage of the shock after each incorrect answer, and if they showed hesitance, the experimenter provided instruction that they must continue. When commanded by the experimenter, all 40 participants continued to shock their learner to 300 volts, the point at which the learner kicked the wall and no longer answered the teacher’s questions. This highlights the power of authority influence, and the strength of the human instinct to obey. Despite acting against their values and assured there would be no punishment for disobedience, participants continued to administer shocks, showing that the human propensity to obey appears to be strong, ingrained, and paramount to other mechanisms such as moral reasoning.
The influence of others is integral to all our actions, whether consciously or subconsciously, and understanding the mechanisms of social influence is valuable for many techniques of persuasion and advertising, as well as in the understanding of social dynamics such as gang cultures.
References
Abrams, D. & Hogg, M. (1990) Social identification, self-categorisation and social influence. European Review of Social Psychology, 1(1), pp. 195-228.
Asch , S. E. (1951). Effects of group pressure upon the modification and distortion of judgments. In H. Guetzkow (Ed.), Groups, leadership, and men. Pittsburgh: Carnegie Press, 1951. Pp. 177-190.
Cialdini, R. & Goldstein, N. (2003) Social influence: compliance and conformity. Annual Review of Psychology, 55, pp. 591-621.
Deutsch, M. & Gerard, H. (1955) A study of normative and informational social influences upon individual judgment. The Journal of Abnormal and Social Psychology, 51(3), pp. 629-636.
Eagly, A. & Chrvala, C. (1986). Sex differences in conformity: status and gender role interpretations. Psychology of Women Quarterly, 10(3), pp. 203-220.
Ferguson, T. (2004) Social influence and conformity [WWW] Utah State University. Available from: http://www.usu.edu/psy3510/influence.html [Accessed 09/04/2012].
Forgas, J. & Williams, K (2001). Social Influence: Direct and Indirect Processes. Philadelphia/Hove, UK: Psychology Press.
Freedman, J. & Fraser, S. (1966) Compliance without pressure: The foot-in-the-door technique. Journal of Personality and Social Psychology, 4, pp. 196-202.
Gudjonsson, G. & Sigurdsson, J. (2003) The relationship of compliance with coping strategies and self-esteem. European Journal of Psychological Assessment, 19(2), pp. 117-123.
Hogg, M. & Vaughan, G. (2005). Social psychology. Harlow: Pearson/Prentice Hall.
Hovland, C. & Pritzker, H. (1957) Extent of opinion change as a function of amount of change advocated. Journal of Abnormal and Social Psychology, 54, pp. 257-261.
Kelman, H. (1958). Compliance, identification, and internalization: Three processes of attitude change. Journal of Conflict Resolution, 2(1), pp. 51–60.
Kelman, H. & Hovland, C. (1953) Reinstatement of the communication in delayed measurement of attitude change. Journal of Abnormal Social Psychology. 48, pp. 327-35
Milgram, S. (1963) Behavioural study of obedience. The Journal of Abnormal and Social Psychology, 67(4), pp. 371-378.
Myers, D. (2008) Social Psychology (9th ed.). New York: McGraw-Hill.
Raven, B. (1965) Social Influence and Power in Current Studies in Social Psychology, Ivan Steiner and Martin Fishbein, New York: Holt, 371-382.