The Power of Social Proof (Part 1)

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Have you ever been in a crowd where no one clapped until one brave soul started the applause? Or walked past two restaurants—one bustling with a line out the door, the other nearly empty—and felt pulled toward the busy one?

These small, everyday moments reveal something big: we are profoundly influenced by the people around us, often without even realizing it.

This episode kicks off a two-part deep dive into social proof, one of the most powerful concepts in social psychology. Over a century of research shows that humans are wired to pick up on social cues, and these cues quietly shape our behavior, decisions, and preferences.

In Part 1, you’ll learn:

• Why simply being around others can change how we perform.
• How reviews, testimonials, and follower counts tap directly into our social wiring.
• The fascinating story of a 19th-century psychology professor who first noticed how cyclists behaved differently when riding together.
• How social proof research has evolved from early experiments in social psychology to today’s social neuroscience.
• The key psychological principles that explain why social proof works.

This episode is about more than just marketing or design tricks—it’s about understanding the deep human need to notice, follow, and be influenced by others. By grasping the science, you’ll build a foundation for creating products, experiences, and messages that feel natural, trustworthy, and even irresistible.

What’s next:

In Part 2, we’ll move from theory to practice. You’ll get concrete methods and examples to put social proof to work in your own designs and projects.

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Transcript

Welcome to The Design Psychologist, the show that helps you use psychology to design
better experiences. I'm Thomas Watkins, your guide to becoming a more powerful
psychology -informed designer. Have you ever been in an audience when a performance
ended and nobody clapped right away? People paused, unsure of what to do,
then one person, maybe you, started clapping. And then and only then did the
applause spread throughout the crowd. Or imagine you're in a new city looking for a
place to eat. You see two restaurants, one has a long line out in front and the
other is almost empty. Which one do you want and why? These little moments may seem
trivial, but they reveal something deeper, we are profoundly influenced by the people
around us, even when we don't realize it. This episode is part one of a two -part
deep dive into social proof, which is a powerful idea with deep roots in social
psychology. Once we start unpacking this, I think you'll realize that you've seen
examples of social proof all around you virtually every day. It's a concept that
shows us just how much our behavior, our preferences, our decisions are influenced by
those around us. And better yet, we'll get into how you can utilize this for things
you design. Over a hundred years of social psychology research has revealed that we
are wired to respond to social cues, but what does that mean for designers and
marketers and anyone who's working to shape human experiences? Can merely being around
others actually change our performance? Why do reviews, testimonials,
and follower accounts influence us so deeply and so automatically? And how can we
apply this realization to the design of products and experiences that feel intuitive
and trustworthy or even irresistible. Understanding the science behind social proof
isn't just about building better interfaces or writing better copy. It's about
activating that social wiring in our heads that helps us form our thoughts,
feelings, and decisions. We'll start with an observation that was made over 125 years
ago by a psychology professor. He noticed something unusual about how cyclists
performed, particularly when they rode near each other. That story will springboard us
into how research has grown and evolved over a century from early experiments in
social psychology to today's social neuroscience. We'll look at key ideas that explain
why social proof works. Along the way, we'll connect these ideas to build a
foundation. Then in the episode that follows this one, we will unpack a whole bunch
of practical methods and examples, empowering you to apply these ideas in your own
work. So, let's dive in with our opening story.
Imagine a warm spring afternoon in 1898. We're on the campus of Indiana University
where cyclists are outside riding their bikes. They're practicing to compete in the
competitive sport of cycling. A professor at Indiana University, Norman Triplett,
is going for a walk. Now while the exact historical scenario is unknown,
he at some point makes an observation that cyclists seem like they might be riding
at different speeds depending on whether they're riding in a group versus riding solo
and whether or not they're competing with the people riding next to them. Later on,
as this innovation lingered in his mind, Triplett's curiosity grew, and he would
investigate this question with a new type of psychology. Now, at this point in
history, psychology is a new science. It's only a few decades old, and it's been
trying to investigate the early questions that various historical thinkers had about
human perception and memory and performance, essentially what's going on inside our
heads, and how does that impact what we do, our behavior? Before psychology existed,
people used philosophy to handle observations like the one triplet made. They would
think about the question or observation in a way that was hopefully thorough or
systematic, but they didn't actually test things. But with psychology now becoming an
increasingly known approach in the late 1800s, the questions that had previously been
handled by philosophy were now being brought into the scientific laboratory. So the
question for what would eventually be known as social psychology is,
how does being around other people change our own psychology? The triplet's specific
question was, "Is it really the case for cyclists that just being near other
cyclists changes their performance?" Now, I'd like you to imagine that deep in the
storage rooms at Indiana University, Norman Triplet is conducting his search.
He began digging through official archives, stacks of old athletic records,
trying to find patterns. Page by page, he looks at these old recorded times jotted
down in tables, and he compares competitive races with solo trials.
And the more he analyzed the data, the more the numbers began to tell a story.
Now, during this time, Triplet did not have access to the same fancy statistical
tools and techniques that we've got available to us today. But, he was still able
to conclude and to show that cyclists rode the slowest when they rode by themselves,
they rode faster when they rode alongside a group of people but not racing, and
they rode fastest when they were riding both in a group and racing against the
people next to them. This might sound obvious, and you might say, "Well, Of course
they rode faster because they were clearly motivated and they were around other
people, but the thing to appreciate here is that people riding solo were still
trying to ride their fastest, so why didn't they? Somehow being around other cyclists
was apparently adding some social element into their mind that made them ride faster.
In other words, Being around other people changes our behavior,
and now we have a scientific way of approaching that, measuring that and exploring
it. Now, Triplett managed to make his discovery using what's called an archival
analysis, which uses existing data. But he wanted to go a step further. He wanted
to construct a novel scientific experiment to test his hypothesis.
He also wanted this experiment to be somewhat easy to run and for the data to be
straightforward to measure. So instead of having participants ride bikes and him
measuring the speed somehow, he would instead have fishing line and have people reel
it in with a fishing pole. And he had children do this. So he had them reel in
line as fast as possible and then he measured how much line they reeled in during
a certain amount of time. What he found was that when children did their best to
reel in as much fishing line as possible, they did better when they were competing
against the child next to them. This experiment is widely regarded as the first
formal experiment in social psychology. So while the more general field of psychology
was trying to tackle the mysteries of what's going on inside of a person's head or
trying to explain their individual perceptions and behavior, social psychology would
set out to view the person within the context of groups and interpersonal
relationships and a variety of other social factors. So now the reason why this all
matters is that much of what we deal with in design psychology frequently comes from
areas like cognitive psychology, which looks at inner mechanisms that drive behavior,
or behaviorism, which deals with how our behavior is modified over time by
reinforcements and punishment. And there are other important contributing fields like
anthropology that have nurtured the history of what we now call design psychology,
especially when it comes to different types of field research. But one often
overlooked area of research that has made a lot of contributions is social
psychology. And it's especially contributed a lot to the modern idea of social proof.
Following Triplets study, we witnessed a long historical trajectory of social
psychology research. That research tradition has allowed us to discover so many
interesting things about how our minds are hardwired to process things socially.
Triplets study, for example, foreshadowed what we would later start calling social
facilitation and its opposite social loafing. Social facilitation is when our
performance gets better when people are around, whereas social loafing is when we get
lazy because we think that the people around us are gonna take care of the task
instead of us having to do it. Other effects that we've discovered along this long
historical trajectory are things like the distinction between attitudes and behavior,
meaning that we say or do one thing and it's not aligned with other things that we
say and do. Or the most famous social psychology phenomenon of all time,
which was discovered by legendary psychologist Leon Fessinger, is known as cognitive
dissonance. And that's where we're uncomfortable because we're simultaneously holding
two conflicting values or beliefs. This is a concept that eventually became so
incredibly commonplace that is used outside of psychology in arenas like business or
politics. One of the big contributing factors to social psychology was around the era
of World War II, when many prominent psychologists became compelled to understand the
nature of authoritarianism and conformity and obedience and norm formation and
groupthink, these ideas had suddenly become relevant because of the atrocities that
the world witnessed during Nazi Germany. We wanted to understand how a previously
normal group of people could get to the point where they're doing such terrible
things on a huge scale. As a result, many prominent thinkers during this era were
Jewish intellectuals who were often directly impacted by having to flee Europe during
that time period. Examples include Kurt Lewin, Stanley Milgram, and a few others.
Milgram, for example, famously contrived fascinating experiments and scenarios that got
otherwise normal people to do cruel things to each other simply because they had
been instructed to do so by an authority figure. That kind of study and many others
showed us things about ourselves that are hard to believe. So, social psychology
continued to evolve and it borrowed many of the tools and methods developed by other
areas like cognitive psychology during the cognitive revolution of the 1950s.
Later we learned about things like the bystander effect, type formation,
group decision making, and all kinds of phenomena, eventually much of what we
previously knew as social psychology merged itself with cognitive psychology and
neuroscience. Thus, today we have the modern cutting edge field that is often
referred to as social
Those three fields still exist individually, but the combined field gets a lot of
attention as the bleeding edge of psychological research. The key point here is that
this long tradition of research has accumulated roughly a few million studies.
That's why we're able to understand things like if a person is smiling in an ad
while looking at us, we pay attention to the person in the ad. But if they're
holding or looking at a product, we pay attention to the product instead. That
example is known as direct gaze versus averted gaze, where direct gaze creates a
greater emotional connection while averted gaze creates better product recall.
So that's just one example, but in the past 130 years or so, we have generated a
ton of scientific data about social human behavior. For most of that history that we
were gathering all that data, we were unable to see the underlying real -time
physiology. But now, armed with things like eye -tracking or data about our skin
responses and heart rate and eventually the holy grail of brain imaging, we can now
estimate a deeper clearer picture of what's going on underneath while we're having
our cognitive experiences. In the end, it turns out that we've got a whole lot of
built -in neural machinery and pathways dedicated to social perception and social
reasoning. There are vast volumes of peer -reviewed articles and books written about
this, But I'll touch on a few examples here of our social superpowers. One being
that we are capable of imagining other people's goals and motivations. This is
something that most animals can't do, and it's called theory of mind. It's the
reason why we can follow the plot of a play, or we can socially maneuver among our
colleagues at work. Or we can fathom a layer of social strategy during a card game
like poker or spades. We are so naturally social that we see faces automatically in
shapes that are just remotely arranged like a face. This is a phenomenon called
facial pareidolia. Pareidolia in general is when we see recognizable objects in things
that are ambiguous. Think about if you're looking at the clouds and you see a horse
or a boat or something, that's called "paradolia." But when you see specifically
faces in things like an electrical socket or a slice of bread, that's called "facial
paradolia." So let's appreciate this. Seeing faces and processing facial expressions
was so important to our evolution that we are hardwired to do it quickly and
easily. We've even got specific parts of our brain like the fusiform face area to
help us do this. And then we've got this gigantic number of observable psychological
effects that reliably show up all the time like in -group versus out -group bias or
the chameleon effect where you naturally start mimicking the mannerisms and gestures
of the people you hang around. And of course, there's social facilitation from our
opening story about the cyclists causing each other to perform better just by being
near each other. All of this is the reason why we use what's called social proof,
and it works like this. Whenever we're trying to sell something, we try to prove to
the potential client or customer that that making this purchase is the correct...
86 billion neurons which are teamed up in different networks of interconnected
neurons. And these neural networks execute specific functions.
And some of these networks are focused and dedicated on executing social tasks,
like judging facial expressions or sizing up social opportunities. So to think about
this a little bit more clearly, our body is made up of lots of different cells
that specialize on different things, skin cells, blood cells, bone cells. Well there's
neurons which specialize on receiving and transmitting signals,
and that's what our brain is made up of, it's 86 billion neurons. So unlike other
cells in the body, neurons arrange themselves to talk to each other in these
intricate networks, you could think of like a web that lights up whenever a certain
stimulus is received or a certain type of thought or feeling happens that this web
of specific sets of neurons lights up because they're all transmitting signals to
each other. These neural networks do specific types of tasks and some of those works
are focused and dedicated on executing specific social tasks like judging facial
expressions or sizing up social opportunities. Social proof is anything that makes you
say to yourself, usually unconsciously, things like, "Other people are happy when they
buy this product," or, "I will have better standing among my peers with this
product. People who are like me love this product, and I should too.
Examples of social proof are things like engagement metrics, such as likes, shares,
comments, and followers. Also, testimonials, where someone is telling you about their
experience with a product. Or client and customer logos, which tell That's clearly
that important companies have used the service. Or how about user reviews and
ratings? Other examples include actual physical crowds that you might see waiting in
line somewhere. Or FOMO signals, which is some kind of evidence that something isn't
going to be around forever. There are also trust badges and case studies and expert
endorsements and so much more. So that was a quick list of some examples of social
proof and we'll go over those in greater detail in the part two episode of this
topic. In this episode, we talked about social psychology and how it's really
important for helping us understand our social minds. And I wanna close out this
episode by introducing an organizational framework to help us think about social
proof. I want to help us connect the psychology with the methods that we'll be
talking about to make it easier to think about. So here's a set of five ideas that
I'd like us to reflect on. One, we relate to humans. Two,
we want to fit in. Three, We trust experts, four,
we're afraid of missing out, and five, our imaginations are key and are often
engaged socially. So to break these down a little bit, let's start with the fact
that we naturally relate to humans. We already mentioned the built -in machinery that
causes us to recognize faces automatically. And a lot of studies have shown in
different ways that we want to relate to and connect with other humans. It's a
stronger effect in some of us than others, but this is an effect that we have at
our core and it's very built in. Next is the fact that we have a desire to fit
in. Related to what's known as social identity theory and the idea of normative
influence, studies show us that we want to adapt our attitudes and behaviors to
align with the groups that we wanna be a part of. Famous social psychologist Tosh
Fell and Turner showed this to be the case in 1979 and has been shown many times
since. More broadly, humans just working together in groups is a fundamental part of
our survival as human beings. So we're hardwired to want to be in groups.
Okay, the next is that we trust experts. This idea comes from social credibility
theory by Hovland and Weiss and the authority principle by Cialdini.
We naturally judge the credibility of those who are giving us information. There are
social cues we associate with authority, related to appearance and tone and
credentials. Judging expertise engages a lot of our social cognition.
The next principle to cover here is the fear of missing out. This scarcity principle
is a cognitive response to the perception of limited availability.
Scarcity Principle, established by Jaldini, combined with temporal urgency developed by
other researchers, deals with the feeling that something will only be available for a
limited amount of time. This isn't inherently social because you can have a limited
resource that has nothing to do with people. However, this principle is very easily
engaged socially in the form of everybody else is getting something and you might
miss out. The last principle here is about our imaginations.
The ability to visualize outcomes can be really important for our ability to actually
achieve it. But researchers Schwartz and seen in the late 90s and early 2000s showed
that vividness has an impact on decision making and motivation.
And this tendency to visualize ourselves achieving is often engaged socially.
We come across this plenty of times in the ads that we see. They are leveraging
our social minds to get us to imagine future states. An ad might show you an
athlete who is winning a competition, which helps us imagine ourselves achieve the
same thing. So, stepping back for a moment, we can see something important has
emerged. Merely being around other people really does change how we act and perform.
And it does so in deeply rooted ways. Early experiments in social psychology
demonstrated this over 125 years ago and research has backed it up ever since.
That's one of the things that makes social proof such a reliable set of tools to
use and design. We are social creatures built to notice what others are doing and
we want to fit in and we look for signals that help us decide what's safe or
what's smart or popular. And that's why things like reviews, testimonials,
follower counts, and expert opinions matter so much. They speak directly to how our
neural pathways make sense of the world socially. If you're working on a design or
marketing project, the next step is to figure out which kinds of social proof work
best in your situation. The goal of part one here was to give us a solid research
foundation for understanding social proof. In the next episode,
we will take our time unwrapping some practical advice and examples. This will help
us think about how to apply specific social proof examples in real world design
work. You've got the foundation now. Up next is the tools to build with it.