EXPLANATIONS FOR CONFORMITY: NSI AND ISI
INTRODUCTION TO NORMATIVE AND INFORMATIONAL SOCIAL INFLUENCE
The distinction between different forms of social influence was formalised by Morton Deutsch and Harold Gerard (1955), who proposed that human behaviour is shaped by two fundamental motivations: the desire to be correct and the desire to be accepted. These correspond to informational social influence and normative social influence, respectively. These are not limited to explanations of conformity or majority influence. They function as underlying mechanisms that explain social influence more broadly, cutting across different social behaviours and contexts.
Compliance is typically driven by normative social influence. Behaviour changes publicly in order to gain approval or avoid rejection, but private beliefs remain unchanged.
Identification is also largely rooted in normative social influence, although it is more internal than compliance. The individual adopts behaviours and attitudes to align with a valued group or role, maintaining this only while group membership is salient.
Internalisation is driven by informational social influence. Here, individuals accept information from others as evidence about reality, leading to genuine and enduring changes in belief.
Obedience can involve both processes. It is often normative, due to pressure from authority and fear of social consequences, but can become informational when the authority is perceived as legitimate or knowledgeable, leading to internal acceptance of instructions.
Minority influence is primarily explained by informational social influence. Consistent and confident minorities provide an alternative source of information, prompting deeper cognitive processing and potential internalisation.
These categories, therefore, provide a unifying framework. Rather than treating conformity, obedience, and minority influence as separate phenomena, they can be understood as different expressions of the same underlying psychological processes
INFORMATIONAL SOCIAL INFLUENCE
Informational social influence refers to a form of social influence in which individuals conform because they believe others are correct. It is driven by a desire to be right rather than to be liked. The individual uses other people as a source of information, particularly when the situation is ambiguous or uncertain.
CORE MECHANISM IN INFORMATIONAL SOCIAL INFLUENCE
The process is based on cognitive internalisation. A person encounters a situation where the correct response is unclear. They observe others' behaviour or opinions and infer that they must reflect reality. As a result, they adopt the same response, not just publicly but privately. The belief becomes genuinely integrated into their own thinking.
This distinguishes informational influence from normative influence. In informational influence, conformity leads to a lasting change in beliefs, not merely surface compliance.
WHY IT INFORMATIONAL SOCIAL INFLUENCE OCCURS
AMBIGUITY: When a situation lacks clear or objective answers. Individuals rely on others as a guide to reality.
CRISIS: In urgent or unfamiliar situations, rapid decisions are required. People assume others possess better knowledge.
EXPERTISE: When others are perceived as more knowledgeable or competent, their behaviour is treated as valid evidence.
CLASSIC RESEARCH: SHERIF (1935)
Muzafer Sherif investigated informational social influence using the autokinetic effect, a visual illusion in which a stationary point of light appears to move in a dark room.
Participants were first asked individually to estimate how far the light moved. Estimates varied widely due to the task's ambiguity. They were then tested in groups. Over time, their estimates converged, forming a group norm.
When tested individually again later, participants continued to use the group estimate. This demonstrates internalisation. The group influence had altered their private judgement, not just their public response.
COGNITIVE EXPLANATION OF INFORMATIONAL SOCIAL INFLUENCE
The process can be understood in terms of uncertainty reduction. Humans are motivated to construct an accurate representation of reality. When sensory or contextual information is insufficient, social information becomes a substitute. Other people function as an external cognitive resource. This aligns with Bayesian reasoning principles. Individuals update their beliefs based on new evidence. In ambiguous contexts, others' behaviour is treated as probabilistic evidence of what is correct.
DISTINCTION OF INFORMATIONAL SOCIAL INFLUENCE FROM NORMATIVE SOCIAL INFLUENCE
Informational influence
Driven by a need for accuracy
Leads to internalisation
Occurs in ambiguous situations
Normative influence
Driven by a need for social approval
Leads to compliance
Occurs in situations with clear norms or social pressure
EVALUATION OF INFORMATIONAL SOCIAL INFLUENCE
STRENGTH: Supported by controlled laboratory evidence, such as Sherif’s study, which demonstrates genuine belief change rather than superficial conformity.
LIMITATION: Often difficult to separate from normative influence in real-world settings. Many situations involve both a desire to be correct and a desire to be accepted.
APPLICATION: Relevant in understanding behaviour in crises, jury decision making, and the spread of beliefs in uncertain environments, including online misinformation, where individuals rely on others as informational sources.
SUMMARY: Informational social influence is a cognitively driven form of conformity based on uncertainty and the assumption that others provide valid information about reality. It produces enduring belief change through internalisation rather than temporary behavioural adjustment.
NORMATIVE SOCIAL INFLUENCE
Normative social influence refers to a form of social influence in which individuals conform in order to be liked, accepted, or to avoid social rejection. It is driven by the need for social approval rather than accuracy. The individual changes their behaviour publicly while often maintaining their private beliefs.
CORE MECHANISM OF NORMATIVE SOCIAL INFLUENCE
The process is based on compliance. A person is aware of the group’s expectations and adjusts their behaviour to fit in, even if they do not agree internally. The change is therefore superficial and temporary, dependent on the group's presence. This distinguishes normative influence from informational influence, since there is no genuine change in belief.
WHY NORMATIVE SOCIAL INFLUENCE OCCURS
UNANIMITY Normative pressure increases when the group is in complete agreement. A single dissenter significantly reduces conformity.
GROUP SIZE Conformity increases with group size up to around three to five individuals, after which the effect levels off.
SOCIAL PRESENCE Normative influence is strongest when responses are public. When answers are private, conformity decreases due to reduced apprehension of evaluation.
CLASSIC RESEARCH ON NORMATIVE SOCIAL INFLUENCE BY ASCH (1951)
Solomon Asch investigated conformity using a line judgement task. Participants conformed to an incorrect majority on a significant number of trials, despite the task being unambiguous. Post-experimental reports indicated that many participants did not believe the group was correct, conforming instead to avoid embarrassment or social disapproval. This supports normative influence as compliance rather than internalisation.
COGNITIVE EXPLANATION OF NORMATIVE SOCIAL INFLUENCE
Normative social influence is driven by the need for social approval and avoidance of rejection. Humans are evolutionarily predisposed to maintain group membership, as exclusion historically reduced survival. Conformity, therefore, functions as a mechanism to preserve social bonds.
DISTINCTION BETWEEN NORMATIVE SOCIAL INFLUENCE AND INFORMATIONAL SOCIAL INFLUENCE
Normative influence, driven by a need for social approval, leads to compliance or identification. It occurs in unambiguous situations
Informational influence, driven by a need for accuracy, leads to internalisation. It occurs in ambiguous situations
EVALUATION OF NORMATIVE SOCIAL INFLUENCE
LIMITATION: ASCH IS HEAVILY CRITICISED. The evidence base is limited by methodological and cultural issues. Asch’s sample consisted of American male students in the 1950s, reducing population validity. The task lacked ecological validity, as judging line lengths is trivial compared to real social decisions. Temporal validity is also a concern, as conformity rates appear lower in more individualistic modern cultures. Demand characteristics may also have influenced behaviour.
APPLICATION OF NORMATIVE SOCIAL INFLUENCE
Normative social influence explains behaviour in contexts where social approval is salient, such as peer pressure, fashion, and public online behaviour.
SUMMARY NORMATIVE SOCIAL INFLUENCE
Normative social influence is driven by the need for acceptance and results in compliance rather than genuine belief change. Supporting evidence is limited by methodological and cultural constraints, so its explanatory power is context-dependent.
