Free samples always brighten up a dreaded trip to the grocery store, especially in the middle of a long day filled with errands. Free cheese? Don't mind if I do! As you move on to the next aisle, your mind stays on the eye contact you made with the sweetest employee who handed you a cube of cheese with hopeful eyes and a warm smile. Even though it was stale after sitting out all day, reminiscent of Gouda (your least favorite cheese), and a whole block is severely overpriced, you find yourself circling back to spend $16 on a wedge of cheese you never intended to buy. Why? Because our brains tell us that a simple “thanks” isn't enough. Small gestures (or someone just doing their job) can sometimes make us feel obligated to reciprocate. As social beings, we follow unwritten rules that help maintain order, guide interactions, and create a sense of predictability. 

Social influence subconsciously taps into almost every aspect of how we navigate the world. Practically every decision we make involves social influence, whether it’s based on how we think people will perceive us, following a suggestion, or imitating others to move through society smoothly. Our need to belong and connect with a group often leads us to act against our best interests to feel accepted. This raises a debate as old as time itself: Does free will actually exist? Or are all decisions we make predetermined by prior experiences and social influence?

Don't worry—many scientists and philosophers believe that we do have free will.¹ It’s just that our freedom to choose is coupled with specific responsibilities that come with participating in society. For example, deciding to change your career path based on your passions rather than external pressure or societal expectations is an act of free will and not a result of social influence. 

The three main types of social influence widely recognized in psychology are:

1. Conformity occurs when we are driven by peer pressure and the desire to fit in. This taps into subtypes of normative influence and informational influence. 
2. Compliance is when we change our behavior in response to a direct request, even if we don't agree, usually (but not always) to avoid conflict. 
3. Obedience is when we decide to follow orders from someone of a higher status. 

Understanding social influence is crucial as most of us are unaware of when it's happening, making it so powerful. When combined with the fundamental elements of human nature, social influence is the driving force behind many of our decisions and actions—like our inherently social behavior, motivation for success, variety of emotions, and desire to maintain a consistent self-concept. It seeps into all facets of our lives, from the workplace to pop culture, health and education, political beliefs, relationships, and consumer behavior. It doesn't just guide what we do—it often dictates why we do it without us even realizing it.

Identification: Adopting a behavior or belief to associate with a group or individual you admire.

Internalization: Fully accepting and adopting a stance because you perceive it as accurate, like a religious belief that you continue to hold even when there are no immediate external influences. 

Normative Social Influence: Refers to the pressure one feels to conform to the group's behavior or beliefs, driven by the desire for acceptance, social approval, or fear of rejection.

Social proof: Is both a psychological and social phenomenon where we tend to copy the actions of those around us to try and conform to a behavior that we believe fits the situation.

Groupthink: A concept that describes how the desire for harmony and consensus within a group can lead to poor decision-making. More specifically, group cohesion is prioritized over critical thinking. 

Echo chambers: An actual or online environment where individuals are primarily exposed to information, opinions, and beliefs that reinforce their own, leading to a decline in exposure to diverse viewpoints.

Bandwagon effect: A psychological phenomenon where individuals adopt certain behaviors, styles, or attitudes simply because others do.

Even in hunter-gatherer times, social influence played a role as they relied heavily on social cohesion for survival. Refusing to share hunted food could harm relationships or damage reputations, so, even if reluctant, we often shared because it was socially expected.³ 

Fast forward to 1898, psychologist Norman Triplett conducted what is widely regarded as the first documented social psychology study. Triplett noticed that cyclists tended to perform better when cycling in the company of a counterpart instead of riding alone, proposing social facilitation theory.⁴ Though it's not conformity, compliance, or obedience in the classical sense, it showed that the mere presence of others can enhance or impair performance due to arousal and competition. 

Muzafer Sherif, a Turkish-American psychologist, first demonstrated conformity, which was later considered one of the three pillars of social influence, in his 1936 experiment.  In this study, participants were placed in a dark room and asked to estimate how far a point of light moved. Due to the autokinetic effect (a visual phenomenon where a static point of light in darkness appears to move), the “movement” was just an optical illusion. When participants were asked to make a judgment alone, their estimates varied significantly. But, when later asked in groups, their approximations converged over time, and participants stuck to a group-established estimate.⁵ Sherif illustrated informational social influence, where people rely on others when uncertain and conform. 

Looking at another central pillar, obedience, we can observe how far people will go to obey authority. Stanley Milgram's groundbreaking 1962 study revealed the shocking degree of obedience to authority under the right conditions. When given incorrect answers during a memory test, participants were instructed to deliver electric shocks to a “learner” (who was a confederate in the experiment). The experimenter, perceived as an authoritative figure, urged participants to increase the shock intensity with each wrong response, even when the learner protested and screamed in pain. Despite the “learner” showing clear signs of distress, over 60% of participants reached the maximum shock level of 450 volts.⁶ Milgram, who was inspired by Nazi war crimes and the defense of “I was just following orders,” concluded that people obey out of fear or out of the desire to appear cooperative. 

In the early 1970s, psychologist Henri Tajfel developed Social Identity Theory, which posits that individuals naturally define themselves based on group membership. Tajfel coined the terms ingroup and outgroup, suggesting that even when created arbitrarily, we tend to favour our group regardless of the meaning behind the group designation. Tajfel's studies became foundational for his social identity theory, which argues that we derive part of our self-esteem and sense of belonging from the groups we belong to. This attachment increases our susceptibility to the group's social influence.⁷

Though social influence has evolved, it still manifests much like it did in hunter-gatherer times, with the underlying psychology remaining essentially the same. One modern understanding is social proof; we trust online reviews and product ratings, just as we once relied on group behavior for survival. On social media, likes and follower counts equate to social validation, amplifying how we experience social influence. Social influence has become a profession taking the form of an “influencer,” and we mimic said influencers by participating in viral trends, often unconsciously, to fit in. Contemporary behavioral economics also capitalizes on social influence studies using techniques like herd behavior, nudging, and framing effects for marketing and pricing. 

Norman Triplett 

A psychologist at Indiana University who is best known for conducting one of the first experiments in social psychology. Triplett's observation that cyclists performed better in the presence of another cyclist was key evidence for his social facilitation theory, which explained how others could influence how one practices a task versus alone. Conversely, when the presence of others negatively affects performance on a more challenging task, he dubs this social inhibition.

Stanley Milgram

During his professorship at Yale University, Stanley Milgram conducted his controversial experiments on obedience. Born to Jewish immigrants in New York City, he was intrigued by the events of the Holocaust and how average individuals were compelled to do such immoral things whilst justifying it by simply “following orders.”⁸ Milgram showed that people are surprisingly willing to harm others when instructed by an authoritative figure, highlighting the power of obedience on social influence. 

Henri Tajfel

A Polish psychologist best known for his pioneering work on the cognitive aspects of prejudice and social identity theory. Tajfel's research showed that self-concept is maintained by affiliation with a valued group, highlighting our desire to belong and the human need for social approval. Our position within these groups can significantly sway behavior and our decisions to remain consistent with social norms and expectations. 

Throughout our lives, we’ve been socially influenced to do (or not do) certain things or to think (or not think) certain thoughts. Whether we're chatting with a friend, running weekly errands, or picking a movie for movie night, chances are the conclusion we reach is not entirely our own. 

Reverse bystander effect & Bandwagon effect

When people see others doing good, they're often inspired to do good. This can be understood as a kind of “reverse bystander effect.” The classic bystander effect is attributed to a diffusion of responsibility—when others are present, we may feel less obligated to help or intervene because we assume someone else will. However, the reverse occurs when many people take action, making us feel socially compelled to follow suit. This can encourage prosocial collective behavior like recycling, donating to charity, or volunteering. It can also fuel social movements and promote lifestyle choices. For example, increased voter turnout is observed when we receive messages like “your neighbors are voting," and climate change protests gain momentum as more people publicly join in.⁹

Similarly, the bandwagon effect is characterized by people changing their behavior and beliefs to match those of others, even if it goes against their beliefs or preferences.  But this isn’t always harmless. Voters might support the candidate already leading in the polls to align with the winning side, despite initially preferring a different candidate.¹⁰ Or, people might not completely understand how cryptocurrency works, but invest in it because it seems like “everyone else is”.¹¹

Foot-in-the-door and door-in-the-face

Without even realizing it, we might have fallen for the “foot-in-the-door” persuasion technique. This is when a small initial request increases the likelihood of us accepting a larger, related request later. For instance, with a free trial of a new streaming service, we're just dipping our toes in, but once we've invested a little bit of time and maybe customized a couple of settings, we form a sense of ownership and commitment. Humans prioritize consistency and maintaining a coherent self-concept, so our internal justification of “I've already used it, so it makes sense to keep going” feels like a smaller jump, and we decide to get that monthly subscription.¹² 

On the flip side, the door-in-the-face technique works in the opposite direction. We might be presented with a large request (where the offeror is expecting refusal), so then we're followed up with a smaller request, which seems more reasonable when compared to the initial one. It relies on our social need to reciprocate. When someone backs down from a large request to a smaller one, we feel compelled to meet them halfway and agree: “Would you be able to help me move my stuff this weekend, all day Saturday and Sunday?” versus “Actually, just an hour on Saturday would be amazing,” is a relief by comparison. 

Scarcity

When an opportunity or item appears rare or limited, we often infer that others must value it, triggering loss aversion (a cognitive bias suggesting that we feel losses more than equivalent gains). This plays directly into FOMO (or the fear of missing out), convincing us that something we didn't necessarily want suddenly became necessary. 

Dating apps boost user engagement with messages like “this match will disappear in 24 hours,” hotel booking sites tell us there's “1 room left at this price,” and it’s not uncommon to be confronted with a checkout countdown timer when shopping online.¹³ Sometimes, scarcity and social proof raise the stakes further. For example, notifications that read: “Only two left—over 500 people bought this today!” The message is clear: a limited supply plus high demand means you'd better act now. 

When overused, this tactic can erode trust. We may feel misled and manipulated and eventually catch on, potentially leading to brand fatigue and skepticism. For the most part, social influence goes under the radar—but when these techniques are abused, we may begin to notice and question. Brands (or people) that rely too heavily on these “effects” to influence others are at risk of turning this psychological tool into a massive red flag. 

The Truman Show had it right: “We accept the reality of the world with which we're presented.”¹⁴ We often comply with invisible social pressures without even realizing it. Our world is complicated by group dynamics that are hard to navigate, especially in high-pressure situations. Whether that's saying no to peer pressure, taking a political stance, or leading a billion-dollar company, none of us are immune to the subtleties of negative social influence. 

Peer Pressure

“Just Say No” was a prominent anti-drug campaign during the War on Drugs in the 1980s that discouraged illegal drug use among children and teens.¹⁵ Whilst catchy, it's easier said than done. Without an understanding of how drugs work and the dangers involved, many school-aged kids are likely just to follow what their peers are doing. The campaign assumed that simply promoting refusal behaviors could override the complex social dynamics that are central concerns during adolescence.

Peer pressure isn't inherently negative like many of us believe it is. Positive role models may encourage us to engage in healthy behaviors, instill good values, and inspire meaningful goals and aspirations. One particularly effective strategy is known as horizontal influence,¹⁶ which is the idea that we are impacted most by those similar to ourselves—another teenager sharing how they quit vaping is more likely to have an effect than a teacher lecturing a class on the harms of smoking. Harnessing peer pressure in this way doesn't fight against teen psychology; it works with it. 

Social Media Manipulation

Social media is the mecca of social influence. Likes, followers, shares, and comments now quantify our sense of social acceptance. The pressure of being “unfollowed” pushes people to conform publicly, seek validation, and actively avoid becoming a “social reject.” This has become exceptionally alarming in the spread of misinformation, where popularity can be mistaken for credibility. 

At the height of the COVID-19 pandemic, when conspiracies like 5G networks spreading the virus distracted people from paying attention to legitimate health measures like wearing a mask.¹⁷ Misinformation is amplified by echo chambers—environments (online or in real life) where repeated exposure to the same beliefs reinforces existing views. These “chambers” are strengthened by social media algorithms that serve personalized content, creating a false sense of consensus and reinforcing confirmation bias, which makes it harder to question or reject false information.
Social media platforms could mitigate the amount of misinformation that circulates—but only if they actively design for it. Motivated by profit margins and engagement metrics, platforms like Facebook and X (formerly Twitter) have ended their fact-checking policies. The circulation of controversial or emotionally charged content undoubtedly boosts user engagement, keeping people liking, commenting, and sharing.¹⁸ On an individual level, we can take things into our own hands by improving our digital literacy, which develops our critical thinking skills and helps us resist manipulation. 

Groupthink

Voicing your opinion or sharing an idea in a group can sometimes be intimidating, especially when you're around experts, managers, or an overbearing colleague. Groupthink describes what happens when we prioritize social harmony over critical thinking or sound decision-making in group settings. To avoid conflict, people may suppress doubts or stay silent, which creates the illusion of unanimous agreement. 

One historical example of how this can have serious consequences is from 1941 when senior officers at Pearl Harbor commanded that warnings from Washington D.C. about a potential attack should be ignored.¹⁹ Groupthink can also crush innovation; a creative or unconventional idea may be mocked or ignored if it diverges from the norm. 

Nokia lost 90% of its market value in just six years when it failed to adapt to the smartphone revolution due to a company culture that lacked communication and innovative vision.²⁰ Another troubling example is when groupthink leads to moral blindness—we might rationalize unethical behavior because “everyone agrees,” which occurred during the Volkswagen scandal when a collective decision was made to cheat on emissions tests.²¹ To avoid groupthink, we can prioritize creating smaller groups, bringing in a devil's advocate, leaders encouraging group participation to reduce top-down influence, and asking for input from external stakeholders. 

The Internet…

The internet is a strange place where people often disregard common sense and safety guidelines, posting videos of themselves eating laundry pods on YouTube. What could possess us to do such a thing? Normative social influence and our desire to fit in can outweigh logic and self-preservation. 

For teens, peer-driven influence and algorithmic amplification can make it seem like everyone is participating in the latest TikTok fad. These trends spread quickly via heuristics; if a friend posted it, it must be okay; if everyone's doing it, it's probably fun. These mental shortcuts let obscure internet challenges sneak past our critical thinking, and before we know it, we're attempting to drink a can of Sprite as fast as we can without vomiting—and then uploading the evidence for everyone to see. 

Posting a photo with a particular pose, a new phrase entering our vocabulary, or trying a new trendy cafe are micro-actions that offer social connection and instant gratification. Ultimately, small behavioral shifts are harmless and part of being human, and we mimic others to feel safe and accepted. However, access to the internet is commonplace, and younger generations don't have the tools to evaluate harmless trends from dangerous ones, finding themselves in unfavorable situations all because Tom from TikTok says it “boosts aura.”

Internet social influence at its worst? Fyre Festival was organized in 2017 by American businessman Billy McFarland and rapper Ja Rule. The luxury music festival was to be hosted on a private Bahamian island and endorsed by several major influencers, making it the event of the year. Thousands flocked to the island, but instead of luxury hotels and catered food, attendees arrived to mattresses in blow-up tents, cheese sandwiches, and no music. McFarland was sentenced to six years in jail for fraud,²² and Netflix produced “FYRE: The Greatest Party that Never Happened,” highlighting how high-status endorsements and perceived social exclusivity (i.e., scarcity) can override skepticism despite the presence of major red flags that signaled sketchy leadership and poor organization.²³ 

The Salem Witch Trials

In 1692, a series of investigations broke out in Salem, Massachusetts, when a group of girls aged 9-17 claimed to be tormented by the spells of women practicing witchcraft. At the heart of the Salem Witch trials were religion, superstition, and unease due to the arrival of non-Christian immigrants. 

Minister Samuel Parris's daughter and niece were among the first to make accusations, naming Sarah Good (a homeless woman), Sarah Osborne (a wealthy landowner who hadn't been to church in years), and their housekeeper, Tituba (who was kidnapped and sold to Parris in Barbados) of witchcraft. Good and Osborne were hanged despite claiming innocence. Tituba, on the other hand, confessed, which popularized and legitimized the idea of witchcraft amongst the community. However, Parris had actually beaten the confession out of her.²⁴

The “witch hunt” escalated rapidly due to a multitude of social influence dynamics at play. Martha Corey and Rebecca Nurse were charged as witches due to their denial of witchcraft’s existence. This led to normative social influence, causing people to conform to the hysteria to avoid outward ostracism or being accused. Minister Parris took control of the narrative, shutting down dissent and promoting groupthink. Additionally, Bible verses were used to justify accusations and executions, and every action was backed by the need to obey religious authority.²⁵

Though it's easy to dismiss the 1600s as a superstitious anomaly, the Salem witch trials remain a historical example of how mass social influence can override morality and logic. It took over a decade for Ann Putnam Jr., one of the original accusers, to publicly apologize and admit that the deaths were of innocent people. By then, over 20 people were executed,²⁶ and Salem learned too late that social influence can be far more dangerous than an alleged spell. 

Behind the Screens: Using AI to Dissect Social Media Persuasion 

Want to resist the persuasive pull of social media? This article explores how you can use AI, particularly large language models to break down how platforms might influence your thinking. By learning how to classify data into low and high construal levels, we can determine how credible information is. 

Harnessing Social Norms for Social Good - The Decision Lab 

This article offers a step-by-step guide on using social norms positively, drawing on insights from author Paul Deutchman. Understanding the differences between descriptive and injunctive norms, emphasizing a normative focus, and applying positive and/or negative framing can promote prosocial behavior and change.

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