Social influence is the process through which the presence, behaviour, expectations, communication or perceived opinions of other people affect an individual's or group's thoughts, feelings, attitudes, decisions or behaviour. It is a central concept in social psychology and is also relevant to sociology, communication studies, education, marketing, organisational research and political behaviour. Social influence can be intentional or unintentional, direct or indirect, conscious or unconscious.
A person may change behaviour because another person explicitly requests it, because a group establishes a norm, because an admired individual provides an example, or because the individual anticipates how others will react. Social influence therefore encompasses a wide range of processes rather than a single mechanism.
Several forms of social influence are commonly distinguished. Conformity involves adjusting behaviour or attitudes toward perceived group norms or expectations. Compliance involves changing behaviour in response to a request, whether or not the person privately agrees with the request. Obedience involves responding to a perceived legitimate authority. These concepts overlap because all involve effects of other people, but the source and mechanism of influence differ. Social influence can also operate through persuasion, modelling, social comparison and normative expectations. A person may compare their performance with peers, adopt a behaviour observed in a respected colleague or change an opinion after receiving a persuasive argument. The specific mechanism matters because different forms of influence involve different psychological and social processes.
Social influence can arise because people use others as sources of information. In uncertain situations, individuals may assume that other people possess relevant knowledge and may therefore follow what appears to be the majority response. This informational process differs from normative influence, in which people adjust behaviour because they want to be accepted, avoid disapproval or conform to expectations. The two processes can occur simultaneously.
A person may agree publicly with a group because they genuinely believe the group is correct while also recognising that disagreement could carry social costs. Social influence is therefore not necessarily superficial or coercive. It can produce genuine changes in beliefs when people regard others as credible sources of information.
Social networks are important channels of social influence. People are more likely to encounter and be influenced by individuals with whom they communicate regularly, but influence can also travel through larger networks. Friends, family members, colleagues, teachers, leaders, public figures and online communities can all shape perceptions and behaviour. Network structure affects exposure because some individuals occupy positions connecting otherwise separate groups. Digital platforms can amplify influence by allowing information, norms and behaviours to spread rapidly through large populations. However, exposure does not guarantee persuasion. People interpret messages through prior beliefs, identities and experiences, and competing sources of influence can produce different outcomes.
Social influence is closely connected with norms. Social norms are expectations about appropriate behaviour, and people often use perceived norms to decide what conduct is acceptable. Descriptive norms concern perceptions of what people commonly do, while injunctive norms concern perceptions of what people approve or disapprove of. These distinctions matter because behaviour can be influenced both by beliefs about what is typical and by beliefs about what others expect.
Institutions and communities communicate norms through rules, rewards, sanctions, rituals and everyday interaction. Individuals can also resist norms when they regard them as illegitimate or inconsistent with personal values. Social influence therefore includes both conformity and resistance because social expectations provide a reference point against which behaviour is interpreted.
Power and status can substantially affect social influence. People with recognised authority, expertise, prestige or institutional control may have greater capacity to shape others' decisions. A teacher can influence students through legitimate educational authority, while a specialist can influence decisions through perceived expertise. Status can also affect whose statements receive attention in group discussions. However, influence is not determined solely by formal power. Individuals without official authority can shape behaviour through expertise, reputation, social networks or symbolic importance. Understanding social influence therefore requires examining the relationship between the source and target, the legitimacy of the source, the information available and the social consequences associated with accepting or rejecting the influence.
Social influence can have both constructive and harmful effects. It can encourage cooperation, learning, healthy behaviour, adherence to safety procedures and participation in community activities. It can also spread misinformation, prejudice, harmful practices or destructive group norms. The same mechanisms that allow useful knowledge to circulate can allow inaccurate information to spread rapidly. Individuals may also conform to group behaviour that they would reject independently. For this reason, social influence should not be equated with manipulation or coercion. Influence ranges from ordinary learning and coordination to deliberate persuasion and coercive pressure. The ethical and social significance depends upon the content of the influence, the freedom of the target, the methods used and the consequences produced.
Social influence is ultimately a fundamental mechanism through which social environments shape individual and collective behaviour. It explains how people acquire norms, revise opinions, coordinate action, respond to authority, compare themselves with others and adopt behaviours observed in their communities. It operates through information, persuasion, expectations, identity, status, networks, rewards and sanctions. Because influence can be voluntary or involuntary, beneficial or harmful, direct or indirect, it cannot be reduced to manipulation. A complete analysis asks who is influencing whom, through what mechanism, under what social conditions, with what degree of power and with what consequences. This makes social influence central to understanding conformity, cooperation, socialisation, group behaviour and the transmission of beliefs and practices.
