Social Proof is our tendency to view a behavior as more correct to the degree that we see others performing it. We determine correct behavior by seeing how others are acting, and then we adjust our behavior accordingly.
In this post we'll examine what social proof is, different forms of social proof, examples in our daily lives, and when social proof can lead us down very dark roads.
Humans are naturally social creatures. We have evolved in such a way that our brains are wired to connect with one another. We need human connection and we feel pain when those connections are threatened. 
We feel safe and secure when we "fit in" with others so we're unconsciously always trying to achieve that state. In Social, Matthew Lieberman says, "Our brains are built to ensure that we will come to hold the beliefs of those around us." 
We compare our behavior to the behavior of others and if the two are incongruous we feel pressured to adjust accordingly. In this way, the principle of social proof derives from comparison and conformity.
Dr. Robert Cialdini has written extensively on social proof also called social influence. In his best-selling book, Influence, he defines social proof as viewing "a behavior as more correct in a given situation to the degree that we see others performing it."  He continues,
We determine what is correct by finding out what other people think is correct. The principle applies especially to the way we decide what constitutes correct behavior.
Social proof influences us in both big ways and small. As Cialdini puts it,
Whether the question is what to do with an empty popcorn box in a movie theater, how fast to drive on a certain stretch of highway, or how to eat the chicken at a dinner party, the actions of those around us will be important guides in defining the answer. 
As is the case with almost all human behaviors: if it still exists it likely serves some purpose to us. Social Proof is no exception.
As Robert Cialdini explains:
The tendency to see an action as appropriate when others are doing it works quite well normally. As a rule, we will make fewer mistakes by acting in accord with social evidence than by acting contrary to it.
Usually, when a lot of people are doing something, it is the right thing to do. This feature principle of social proof is simultaneously its major strength and its major weakness.
Cialdini, along with Noah Goldstein and Vladas Griskevicius wrote a paper called A Room with a Viewpoint, published in the Journal of Consumer Research in 2008. They wrote,
When consumers learn that seven out of 10 people choose one brand of automobile over another, that teeth-whitening toothpaste has become more popular than its less functional counterpart, and that nearly everyone at the local cafeteria steers clear of the “spamburger surprise” entree, they are getting information about social norms. Specifically, they are getting information about descriptive norms, which refer to how most people behave in a situation. Descriptive norms motivate both private and public actions by informing individuals of what is likely to be effective or adaptive behavior in that situation. A wide variety of research shows that the behavior of others in the social environment shapes individuals’ interpretations of, and responses to, the situation, especially in novel, ambiguous, or uncertain situations.
When we are uncertain of what to do in a given situation we look at what others are doing.
This has become a fundamental part of marketing, for example. When consumers are unsure of what product to buy they will weight heavily outside reocmmendations. They will also look to see what other people are using or buying.
Unfortunately, this has even more sinister consequences. Uncertainty, as part of social proof, leads to the Bystander Effect. The Bystander Effect is when nobody helps a person in distress because they notice that nobody else around them is offering help. A person's inaction results when they observe the inaction of others and conclude that nothing needs to be done. This is why the bystander effect is sometimes called Bystander Apathy, or Pluralistic Ignorance.
Think: "If I am uncertain how to behave, I will take a cue from others."
The reverse effect can happen too. When we see others do something we know is wrong, we're more likely to assume that it is alright for us to do it as well.
This can be tourists trying to sneak pictures when it's not allowed if they see others getting away with it. It could also increase the number of people jaywalking or littering.
But, as with uncertainty, there are more severe consequences of social permission. Social permission can explain part of how peaceful crowds can morph into unruly riots. It can also help explain how some young people are drawn to drugs and violence when they see their peers acting in that way.
Think: "If other people are doing something, it must be ok for me to do it too."
Finally, social proof influences many of the "social taboos" in society. If a person's behavior is met with disapproval from those around them, they are likely to change their behavior.
If we conform to the behaviors we see around us, we are less likely to make a social faux pas.
This too can have serious consequences. Young children may be less likely to express their individuality out of fear of being bullied for being different. It also has a big impact on the LGBTQ community. It also can inhibit asking important questions in the workforce if the work environment places a high importance on appearing to always have the answers.
Think: "If other people are refraining from doing something, then it is probably not a good idea for me to do it."
The use of laugh tracks in modern TV comedies is a great example of social proof. Audience members may say they dislike laugh tracks, and they may truly feel that way but the science repeatedly shows that canned laughter makes people laugh.
Experiments have found that the use of canned laughter causes an audience to laugh longer and more often when humorous material is presented and to rate the material as funnier.
However, for those that claim that laugh tracks cheapen the comedy, there is evidence to support that as well.
"Evidence indicates that canned laughter is most effective for poor jokes." 
Advertisers love to exploit social proof. Rather than convince us directly that a product is good, often ad-copy will use terms like “fastest growing” or “#1 best-selling... ” Unconsciously our brains think all of these other people can't be wrong.
If you've ever seen an advertisement that says, "4 out of 5 doctors recommend..." that's social proof at work. Advertisers are hoping that you'll delegate your thinking and just buy the one the doctor "recommends."
Bars and night clubs limit entry and make customers wait in line outside. This visual of others waiting in line for something increases the perceived popularity of the venue. The long lines are meant to "convince potential patrons that this must be where all the action is." 
Social Proof is also often exploited for donations. If you see a donation jar with money in it, you are more likely to feel pressured to give money as well. With this in mind, it's a common practice for coffee shops and church to 'salt' the donation jar or collection plate.
A little ‘salt' helps increase donations and research shows that 'salting' with larger bills yields larger collections. This likely is due to a combination of social proof and anchoring.
Baristas, clever as they are, often salt the tip plate with “large change” and quickly remove pennies and nickels. 
Social proof has become a fundamental part of social networks such as Twitter, Facebook, Instagram, and YouTube.
The rise of social media means, more than ever before, we can quantify an audience. We can see the number of likes, fans, views, followers, and comments that a person or post has and that number affects how we perceive the material, regardless of its objective value.
Having more likes or followers makes people perceive your message as more trustworthy and reputable than someone with a similar message but less engagement.
This has led to the rise of a clandestine multi-billion dollar industry focused around ghost followers. Ghost followers are non-human accounts dedicated to liking and sharing online material, for a fee of course. This industry exists for the sole purpose of exploiting social proof on social media.
Social proof is also used on many other kinds of websites. Many blogs will have a bar somewhere on the screen showing the number of times the article has been shared on various social media sites. This can work both for and against a website. If the numbers are very large, new readers are likely to regard the blog as good and trustworthy. If the numbers are low, readers are more likely to leave and find a different source.
Recently, email newsletters have quickly risen in popularity. One technique that is frequently used to entice others to sign up is citing the number of people that are currently on the email list. Again, our brains make us think that an increase in popularity is an increase in validity. We need to be wary of this false association.
Social proof is a vicious problem in the investment world. There are frequently situations in which an investor has limited time to make a decision. When unsure what to do, many investors will look at what so-called experts are doing. Unfortunately, the world of finance is full of people who claim to be an expert in something.
Social proof is amplified when the members of a group are similar, when everyone looks and acts the same. This presents a large challenge in the financial investments industry which overwhelmingly comprises white males who wear suits and all attended the same top colleges.
These two main factors: investors feeling pressured to follow experts and tending to listen to others who are similar to them provides a psychological explanation for the herd mentality that is so prevalent in the markets. 
Word Of Mouth
Nielsen, a data and information company, collects and reports data on many topics. You may have heard of them from the Nielsen Families, but their scope is much more far reaching than just TV.
A Nielsen report from 2015 says that the most meaningful form of advertising, especially among millennials, is word-of-mouth recommendations. In fact, 83% of consumers say they trust word of mouth recommendations more than any other form of advertising . We care what our friends and family are interested in and we use those opinions to help form our own thoughts on things.
Steven Dubner and Steven Levitt address social proof and word-of-mouth influence in their book Think Like a Freak. They remind us that humans like to run with the herd. We like to adopt the views of our family, friends, and colleagues. We are "quick to embrace the status quo, slow to change our minds, and happy to delegate the thinking." 
The Magnifying Effect
Back to Top ↑
Magnified by Groups
Social proof works when we observe the behavior of another individual but its effect is multiplied when we see similar behavior from many people.
Albert Bandura's research into phobias revealed that children who were afraid of dogs quickly learned to overcome their fears merely by watching another child playing happily with a dog. More significantly, children learned to overcome their fears by watching film clips of the same behavior. This technique is particularly effective when the clips show a variety of children interacting safely with the dogs.
"The principle of social proof works best when the proof is provided by the actions of a lot of other people" . Imagine, then, the impact of movies or television to influence the behavior of an entire society.
Magnified by Similarity
The effects of social proof are also magnified when then individuals in the group are similar. I mentioned this briefly in the section on investing. Cialdini explains that magnification by similarity is one of the reasons you'll see "ordinary" people giving testimonials on TV or on websites. Cialdini continues,
"We will use the actions of others to decide on proper behavior for ourselves, especially when we view those others as similar to ourselves." 
Later in Influence, Cialdini tells the charming story of his son learning how to swim. His son learned how to swim not from his father nor from a lifeguard. Ultimately it was another boy his age who had already learned how to swim.
If we're more likely to learn from those similar to us, what impacts may this have on education? To what extent do we learn from our peers over our teachers?
Back to Top ↑
When a person's belief is found to be false, the person, in an attempt to save face, may exhibit increased fervor in their beliefs.
Festinger, Riecken, and Schachter are the authors of When Prophecy Fails. They demonstrate the power of social proof by telling the story of the Seekers, a doomsday cult who predicted an imminent apocalypse. They discuss the coping mechanisms used after the event did not occur.
The Seekers predicted that the world would end in a great flood before dawn on December 21st, 1954, and believers would be saved by spaceships that would carry them to the fictional planet Clarion. The sun rose and set on the 21st and, of course, there was no flood.
The Seekers, in response to their beliefs being exposed as false, exhibited increased fervor in those beliefs. They were so invested in their beliefs that they could not risk giving them up. (This is also an example of the sunk-cost fallacy).
"The group members had gone too far, given up too much for their beliefs to see them destroyed; the shame, the economic cost, the mockery would be too great to bear." 
This is a classic example of the defense mechanisms popularized by Sigmund Freud. Their reflexive and defensive behavior protected them from the pain of recognizing an unbearable truth. Cialdini explains the cult members turned from "secretive conspirators to zealous missionaries" in an attempt to gain other converts, even though their beliefs had been shown to be baseless. Their actions were motivated by the beief that "the greater the number of people who find any idea correct, the more the idea will be correct." 
When Prophecy Fails, lists five conditions that must be present for an individual to double down on beliefs after a failure or disconfirmation. The fifth and final belief is:
"The individual believer must have social support. It is unlikely that one isolated believer could withstand the kind of disconfirming evidence that has been specified. If, however, the believer is a member of a group of convinced persons who can support one another, the belief may be maintained and the believers may attempt to proselytize or persuade nonmembers that the belief is correct." 
The Werther Effect
Back to Top ↑
The Werther Effect is an example of social proof as it related to suicide based on the research of David Phillips.
Phillips studied suicide statistics in the United States from 1947 to 1968. Phillips discovered that "within two months after every front-page suicide story, an average of fifty-eight more people than usual killed themselves" and that "this tendency for suicides to beget suicides occurred principally in those parts of the country where the first suicide was highly publicized and that the wider the publicity given the first suicide, the greater the number of later suicides" .
The consensus at this point is that these are copycat suicides. They normally take the form of airplane and automobile crashes. This is likely an attempt to be more surreptitious about their purposeful death. They engineer an accident rather than killing themselves directly.
So powerful is the effect of social proof, if the publicized suicide is a young person, there will be young people dying in accidents for the weeks following the story. 
This specific kind of social proof extends beyond suicide. Any type of publicized aggression has the "nasty tendency to spread to similar victims, no matter whether the aggression is inflicted on the self or on another."  Publicized aggression can take the form of homicides, heavyweight boxing matches, or street fights. Violent images stimulate an increase in copycat behavior.
Knowing this, there are some strong ethical considerations we need to make regarding media coverage of suicides, homicides, and aggressive sports events. Should media companies publicize suicides if we know that it's likely to lead to more deaths?
Uncertainty in the Peoples Temple
Back to Top ↑
To demonstrate the potentially very dark side of social influence we'll look one of the most disturbing events in recent history: the 1978 Jonestown, Guyana mass suicide orchestrated by the Reverend Jim Jones.
In November of 1978, 910 members of The Peoples Temple voluntarily drank cyanide-laced grape juice at the prompting of their spiritual leader. 
Dr. Louis Jolyon West explains that this event was likely only possible because of their relocation to Guyana. He says "This wouldn't have happened in California. But they lived in total alienation from the rest of the world in a jungle situation in a hostile country." 
In this environment, the members of the Temple found themselves inundated with uncertainty and as discussed, uncertainty activates the effects of social proof. In Jonestown, Jones' followers, in their collective state of uncertainty, looked to others for signs of correct behavior. When they looked around, they saw people like themselves taking the poison.
Social proof was activated by uncertainty and amplified by the similarity of the members in the group. Everyone who drank the poison that day died, over 900 people, including more than 300 minors. The Jonestown mass suicide was the largest single loss of American civilian life in a deliberate act until September 11, 2001.
According to Cialdini, Rev. Jim Jones was able to orchestrate this because of his understanding of social psychology.
"Isolate a group of like individuals in an alien environment and their sense of uncertainty will turn them into a herd of followers." 
The Buffalo Jump
Back to Top ↑
Cialdini finds the image of the buffalo jump to be a fitting analogy to explain social proof as a weapon of influence.
Social proof is our auto-pilot mode. It's usually quite useful for navigating social interactions. We look to see how others like us are behaving and we modify our behavior accordingly.
However, sometimes the information on which our autopilot relies is inaccurate. We need to stay vigilant to the pressures of social proof by being aware of evidence of a false response. When we are aware of how our brain is thinking we can take the controls away from the autopilot.
Back to Top ↑
 Lieberman, Matthew D. Social: Why Our Brains Are Wired to Connect. Oxford, United Kingdom: Oxford U Press, 2015. Print.
 Cialdini, Robert B. Influence: the psychology of persuasion. New York, NY: Harper Business, 2006. Print.
 Soules, Marshall. "Influence: The Psychology of Persuasion." Media Studies. Malaspina University, n.d. Web. 6 May 2017.
 "Social Proof: Why We Look to Others For What We Should Think and Do." Mental Models. Farnam Street, 19 May 2017. Web. 13 Nov. 2016.
 Fox, Eric. "4 Biases That Can Make You A Bad Investor." Financial Edge. Investopedia, 28 Sept. 2016. Web. 10 Feb. 2017.
 "Recommendations From Friends Remain Most Credible Form of Advertising Among Consumers; Branded Websites Are the Second-Highest-Rated Form." What People Watch, Listen To and Buy. Nielsen, 28 Sept. 2015. Web. 2 Apr. 2017.
 Dubner, Stephen J., and Steven D. Levitt. Think Like a Freak. N.p.: HarperCollins USA, 2015. Print.
 Festinger, Leon, Henry W. Riecken, and Stanley Schachter. When prophecy fails. N.p.: Wilder Publications, 2015. Print.
 Kahalas, Laurie Efrein. "Jonestown: Dismantling the Disinformation." Disinformation. San Diego State University, n.d. Web. 17 May 2017.