Social Proof

Summary: Social proof describes a psychological phenomenon in which people mirror the actions and opinions of others. In other words, people’s decisions are often impacted by the preferences and modeling of individuals or groups around them.

Keywords: informational social influence, marketing, group norms, standards of behavior, testimonials, crowds, social modeling, sales, business, conformity, group conformity, social media

Originator: Muzafer Sheraf (1906-1988)


Social proof was first described in scientific research by a psychologist named Muzafer Sheraf. Sheraf was interested in the impact of groups on individual decision making. In relation to this interest, he completed a famous experiment on group conformity in 1936.[i]

In this study, Sheraf asked participants to observe a blinking light. A blinking light in a dark room often appears to move, even when it remains still. Based on this common perception, Sheraf asked participants to indicate how many inches they thought the blinking light moved. Sheraf first asked participants to guess an answer when they were alone. Then, he asked them the same question again while they were surrounded by a group of other participants. Sheraf found that participants changed their initial answers once they moved to the group setting. Across the board, people changed their number to closer reflect what other group members had guessed.

The concept of social proof came out of studies such as this one. Researchers consistently observe a tendency for individuals to move towards group conformity. Individuals often change their behaviors, opinions, and decisions to match the people around them.


Using Social Proof to Influence People

Social proof is commonly used in marketing and social media to influence people to buy products. Listed below are a variety of different types of social proof that are used in the context of marketing.[ii]

Social proof uses the influence of social media friends. For example, a business might indicate how many of a person’s Facebook friends “liked” a particular product they sell. People are more influenced to buy something when they know that their friends like the product.

  • Social proof uses the influence of celebrities. Research shows that people are more likely to buy a product when it is endorsed by a familiar and well-liked celebrity.
  • Social proof uses the influence of professional certifications and testimonials. Experts in an area may be called upon to endorse a product or provide a testimonial of how they have enjoyed a product.
  • Social proof uses the influence of crowds. Sometimes businesses indicate the number of people who have bought a product. When people know that a product or service is popular, they are more likely to want to buy it.


Social Proof and Personal Decisions

Social proof is a great marketing strategy and an effective means of influencing people to make certain choices. However, individuals should consider if social proof is always the best way to make decisions.

Quite notably, Sharif’s original study indicated that people were not aware of the extent to which they were impacted by the group. When participants where asked if they thought they were influenced by the group, most of them believed they had not been influenced. However, it was clear from the results of the study that people were wrong to believe this.

Negative forms of social proof can lead to bad decision making and giving into peer pressure. A prime example of this is college students who abuse alcohol and drugs.[iii] Research has drawn connections between social proof and this common dangerous behavior in college students. On a college campus, so many people engage in substance abuse that this behavior is observed to be the norm. Incoming students are apt to conform with the group and begin abusing substances just like the older students around them.

It is not always wrong to make decisions based on social proof. However, Sharif’s study provides an important caution that people should develop self-awareness surrounding this topic, so they can know when their decisions are being influenced by the people around them.



[i] Sherif, M. (1936). The psychology of social norms. Oxford, England: Harper.

[ii] Talib, Y. Y. A. & Saat, R. M. (2017). Social proof in social media shopping: An experimental design research. SHS Web of Conferences, 34

[iii] Cullum, J., O’Grady, M., Armeli, S., & Tennen, H. (2012). Change and stability in active and passive social influence dynamics during natural drinking events: A longitudinal measurement-burst study. Journal of Social and Clinical Psychology, 31(1), 51-80.