The Power of Social Proof (Part 2): 18 Methods Across 5 Psychological Drivers

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Why does social proof work?

And, what are some practical tips on how to use it to create better designs?

In part one of these Social Proof episodes, we started with the foundations of social psychology. We looked at the history, key studies, and some helpful frameworks.

Now in part two, we’re picking up where we left off—at the five-point framework I mentioned at the end of Part One. This is where things get practical. We’ll connect the social psychology research with actual strategies for implementing social proof. 

We’ll explore how social proof methods like testimonials, expert endorsements, and more, have an impact on our psychology, in particular, when we’re making buying decisions.

By the end, you’ll have a framework to decode social proof and a toolkit to apply it thoughtfully.

What You’ll Learn

• Five core psychological drivers— including our need to fit in, our fear of missing out, and so on  
• How social proof methods like testimonials, expert endorsements, and more, have an impact on our psychology, in particular, when we’re making buying decisions. 
• A framework to decode social proof and a toolkit to apply it thoughtfully. 

Key Takeaways

• We relate to other humans, and shared experiences matter.
• We want to fit in—and social proof taps into that drive.
• We trust experts when making decisions under uncertainty.
• We’re motivated by FOMO (fear of missing out).
• Imagination helps us take action when we see others doing the same.

These drivers explain why social proof works. We respond to stories, signals, and shared experiences because they tap into how our minds are wired.

We also explored how to use social proof in design. Whether it’s testimonials, expert endorsements, client logos, or user-generated content, each method works best when it feels real, relevant, and respectful. The goal isn’t to trick users—it’s to guide them with clarity, trust, and connection.

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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. Why does social proof work?
And what are some practical tips on how to use it to create better designs.
In part one of these social proof episodes, we started with the foundation of social
psychology. We looked at the history, key studies, and some helpful frameworks.
Now in part two, we're picking up where we left off at the five point framework I
mentioned at the end of part one. This is where things get practical. We'll connect
the social psychology research with actual strategies for implementing social proof.
To do this, we'll walk through the five core psychological drivers, including our
need to fit in, our fear of missing out, and so on. We'll explore how social proof
methods like testimonials, expert endorsements, and more have an impact on our
psychology, and in particular, when we're making buying decisions. By the end,
you'll have a framework to decode social proof and a toolkit for applying it
thoughtfully. Let's dive in.
So let's look at these five points or five constructs as an organizational framework.
It'll help us think about social proof in terms of what these methods are actually
doing psychologically. So the five constructs of our framework are as follows.
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 really important and they're often engaged socially.
So here's what I'm gonna do. I'm gonna walk through each one of these social proof
methods and for each one I'm gonna give you an example. I'm going to introduce the
method itself and then talk about recommendations for if you want to apply these
things to a design scenario. So let's dive in looking first at the social proof
method of testimonials. Imagine you're in the middle of a career switch and you're
browsing online classes to take. You're trying to figure out what kind of course
would be realistically valuable to you. On one website you come across,
you see a testimonial from a person who seems similar to you. You see a little
profile picture of them in their name. You read their statement where they Describe
what they were looking for when they signed up for the course. And they also talk
about how happy they are now that they're done with a course and what valuable
effect it's had for them. So now you find this testimonial to be relatable and
believable. It makes this particular course offering seem like the right thing to do.
When you display testimonials, you want to make sure you show authenticity, to make
sure that that human connection is present. This means using real names,
real photos, job titles whenever possible. And if you want to add an extra dimension
to this testimonial experience, consider using video testimonials. If you do this,
you want to make sure that the speaker looks really authentic and unscripted. This
gives you an opportunity to show things like facial expressions, body language, and
other communication nuances that would otherwise be difficult to relay in printed
text. Now, keeping with this idea that we like to relate to other humans,
let's look at the social proof method of user reviews and ratings. Imagine you're
online booking a hotel room. You see that one hotel has a four out of 5 star
rating. With most people giving it a 4 or a 5, but then a sizeable chunk of
people giving it a 1 or 2. So you click to see specifically the reviews in the
lower range, they're telling stories but they don't seem like they relate much to
you. For example, they were mad about the surprisingly small rooms,
but small rooms don't bother you. and they mention a few other things that you
don't feel are very applicable to you and your situation. Most of the people you
relate to in the reviews seem to be pretty happy, so you go ahead and book. Your
judgment on whether or not to purchase was partly based on how much you could
relate to other people's experiences. There was a meta -analysis published in 2014 by
Floyd et al. in the Journal of Retailing. They compiled a bunch of research dealing
with the question, "If you have user reviews on your website, how does this
correlate to sales and how should you display these reviews?" This meta -analysis took
the results of 26 studies and arrived at some recommendations. To mention a few of
them here, reviews matter more for products that people have an actual experience
with, like hotels and restaurants, as opposed to more utilitarian products like tools.
And there were two variables that were both hugely important, one being the level of
positivity or negativity of the ratings, and two, how many or how few.
In other words, if something had tons of meetings that seemed very compelling. And
since the authenticity of the reviews is immensely important, nobody wants to read
possibly fake reviews, you want to use a reputable review platform on your site if
that's plausibly available to you. For another closely related method, let's look at
user -generated content. Imagine you're on social media and you see someone comparing
different brands of hiking boots. It's not an official review, it's just a peer,
a regular person talking about their experiences hiking and trying out different
boots. Reading it, you find the recap of their experience to be very authentic.
All the rest of their content seems normal and has nothing to do with selling. All
their other stuff is about just normal life stuff, so you find their hiking boots
discussion to be pretty authentic. So if you want to include user -generated content
effectively, you want to have a platform that facilitates community and discussion.
Allow things like hashtags and other ways people can make their content findable. You
want to make it easy for people to produce content and even to curate collections
and playlists that can be shared. The more connected and free people feel while
expressing themselves, the better. Another very similar social proof method would be
customer quotes. Imagine you're browsing some weight loss programs online and you come
across the quote, "I lost 26 pounds in three months and the whole process was very
convenient. You look at the person who supposedly said this and you unconsciously
feel like this person might be similar to you. Now, this is almost the same thing
as testimonials and reviews. It's a tiny bit different in that it's typically just a
short punchy statement, not directly posted by the person. Think of a statement that
you yourself would want to make about your own product, but that would lack
credibility if you said it yourself. For example, you could make the claim that your
product can help people lose 26 pounds in three months, but it's better to have
someone who actually did it say it about their own experience. So when you do
customer quotes, make it known that it's a real person who said it. To help achieve
this, you want to include photos or company logos, if that's relevant, and perhaps
verifiable details about that person. Plus, you want it to be a short,
impactful snippet of a statement that doesn't take up a whole lot of space and
isn't a prominent position on the page. Think of it as a microtestimonial.
Imagine you're shopping for a gift for your dad, and you remember that you're
actually following this dude on social media who is known for giving style advice to
men. You scroll through his feed and you find him promoting this sport jacket that's
got a very smooth yet very classic feel to it. It's not the sport jacket that you
would have picked on your own, but it does look good. And this influencer does have
a ton of people following him so it seems like he knows his stuff so you decide
to buy this new stylish jacket for your dad. An influencer partnership is usually
when a company gets a already popular influencer to showcase and discuss their
products. You the social media user already know this influencer from other contexts
and so therefore you have some sense of connection with this influencer. And now
that connection is being leveraged for the sales pipeline of a product. A study in
2019 by Lou and Yuan in the Journal of Marketing Communications showed that followers
trusted influencers on factors like seeming similar to your followers,
perceived attractiveness, authenticity. Now, thinking deeper about social connections,
what connection is stronger than people we already know? Imagine you're browsing
LinkedIn and you come across a post that you really enjoyed reading. You click on
the author profile and you're deciding whether to connect with them. Then you see
the words, "You and this person have eight people as mutual connections." And you
say, "Oh, cool, I wonder how she knows Arun." Now it feels like a no -brainer to
reach out and connect with her. She seems almost like part of your tribe already.
Let's look at the social proof method of peer validation. Similar examples elsewhere
on the web might be things like, "People you know liked this post," or, "People who
viewed the same products you're viewing also viewed these products. This all deals
with validating possible options with people's existing peers, and peers that people
know personally works even better. There's this often quoted 2015 Nielsen Trust and
Advertising report showing that recommendations from friends and family is trusted by
83 % of people a much higher score than other forms of advertising.
In this case, we not only relate to these people, we also fit into the same group.
And that leads us to our second construct for the day, which is that we want to
fit in. So let's go ahead and look through this lens and first check out the
social proof method of crowds. Think about watching a late night comedy show where
jokes are being made and you can hear the crowd laughing in the background. Hearing
the laughter gives us a subtle feel of being among a crowd of people. Studies show
that hearing laughter increases the perceived funniness of the joke, and to enhance
this further, real and spontaneous laughter is even more effective than a laugh
track. but this whole range of things works to one degree or another to exert
normative influence on us. Normal people laugh at this joke we unconsciously feel.
Prouds can be physically live in person or they can be remote and virtual.
And either way, they add a social element to the equation that helps influence our
behavior. Research dating back to the 50s has used this term "the bandwagon effect,"
referring to this well -supported cognitive bias. For physical events,
the power of crowds can be leveraged in instances where people see sold -out signs,
or they see footage of the packed venue that happened at last year's conference. In
the world of print or digital, you can leverage crowds by using labels like "most
popular". Okay, so something slightly different but very similar would be the social
proof method of counts and milestones. Imagine you are trying out a new hobby.
Maybe it's something like crocheting or fishing. You decide that you want to find a
book to help you get better acquainted with the basics. So you go online browsing
and comparing books and you see one book that says over one million copies sold.
Well, that seems like very solid social proof that people are flocking to this book
as a go -to for this topic. The crowd has apparently tested it out for you.
So getting that book feels like a safe move. So you can see that counts and
milestones takes the idea of crowds a bit further by adding numbers and reference
points. In practical application, it is recommended to use statements like one million
sold or 100 ,000 happy customers to reinforce the idea that mass adoption is
happening. Beyond flat numbers, you can even use rates. For example,
you can say growing by 2 ,000 users every week. You can even pair these numbers
with testimonials to highlight the human side of these metrics. For another very
related approach, how about the social proof method of engagement metrics? Imagine
you're on social media trying to gauge where people's opinions stand on some big
current event. You quickly stumble upon one account whose posts are clearly very
popular. You see the huge numbers of likes and shares. There are tons of people
commenting on the posts. It's like every time they say something, it creates a whole
conversation. Then you scroll up to their profile pic and you see that they've got
this gigantic number of followers. If I follow this person, you unconsciously think,
"I'll be where the crowd is when new things happen." So, these likes, shares,
comments, and followers are all examples of engagement metrics. So,
studies have shown mixed results regarding the correlation between social media
activity versus actual purchasing behavior. Some studies,
such as one by Wei Ping Lin et al in 2018, showed a weak relationship.
However, the perception of being popular certainly doesn't hurt in the eyes of
customers. For example, engagement metrics can help your brand be perceived as
popular. How about the very common social proof method of client logos?
Imagine you work for a company and your boss has asked you to pick the tool for
the whole team to use. You find yourself really wanting to feel the least risky.
You go online and you find a product that has great functionality, but it's also a
startup. You aren't really sure it has long -term viability, but then you see on the
website a slow, horizontally scrolling lineup of logos. Now you're starting to feel
confident that this product has been tested by the best, and now you're really ready
to recommend a purchase to your boss. So in practice for this method, it's
recommended that you prominently display the logos of your clients, especially when
they are recognizable and reputable companies in your space.
If these clients spend across many different industries, group them by industry so
that people within one industry can look at one area of the page and see all of
the recognizable players in their space. Robert Caldini, in 1984,
published a book called Influence, Psychology of Persuasion. This was arguably the
precursor to nudge theory, which deals with how you can introduce factors that shift
people's behavior in minor yet meaningful ways. Social proof methods like client logos
can make purchasing more likely, especially if those entities are viewed as
authorities. And this dovetails on the third construct in our framework,
which is that we trust experts. Now you might say to yourself, that's not true.
In fact, you might personally know someone who loves to reject expertise. Maybe it's
someone who gets carried away with conspiracies online and so on. And you might
point out that this person rejects what the experts say, but the question is which
experts? If you look at what that person thinks closely, they probably do trust what
they believe to be experts. Regardless of whatever worldview, there's someone or some
group who we regard as having authority on any given area of information. It might
manifest in inconsistent ways, and this topic is very nuanced. However,
here we're dealing with the observable and reliable effect of humans' trusting
authority and sources deemed to be credible. So let's look at these social proof
method of expert endorsements. Imagine you're browsing through health supplements and
you're not sure whether some of these products are legit and safe. You see that the
label on one of the products has been endorsed by a respected organization, the
Council for Responsible Nutrition. You've never heard of that organization,
but it appears from a quick Google search to be a collection of experts and people
who care about supplements. So you decide to shortcut your decision -making process by
going ahead and trusting the product being endorsed by this organization. Expert
endorsements can come from individuals or organizations and the key thing to focus on
is perceived credibility. A 2004 meta -analysis by Porn Patakpen published in the
Journal of Applied Social Psychology examined credibility level and persuasion and
found among many other findings that Received credibility really does move the needle.
It is recommended from practitioners that you pick recognized industry leaders and
professionals. You should include credentials, titles, affiliations.
You also want to place these endorsements near product descriptions or the various
conversion points on your website. Another very related approach to expert endorsements
is the social proof method of awards and certifications. Imagine you come across some
online show produced by some YouTube channel you've never heard of. You enjoy
watching it and you consider subscribing to it and you see that they've won the
2024 Webby Awards. Realizing that the Webby Awards is a coveted prize in certain
spaces, The decision to subscribe now feels like a no -brainer to you. A couple of
things to think about when using this method, if awards and certifications are
relevant to what you're selling, you want to display either the official seals or at
least some image that represents the award or certification. You also want to stick
with well -known and prestigious awards in that particular industry.
Imagine you're in the middle of a checkout process on a shopping website. As you
checkout, you see a trusted security seal. When you click to pay, a new window pops
up, which is not the vendor's site, but a trusted third -party pay service. Now you
feel totally safe entering your pay information. This is an example of using trust
badges to reinforce safety and security. The idea is that some group of humans out
there whose job it is to care about fraud have placed the necessary protections in
place. Best practices here include using security seals near checkout buttons to add
reassurance. Include icons that represent credit cards and payment services.
All of these things help to communicate some authority and protection around these
potentially risky processes. For another example of leveraging expertise,
let's look at the social proof method of media mentions. Imagine you're interested in
working for a startup and you're trying to figure out whether they actually have a
future. Scrolling through their page, you see that they've been written about in
various tech crunch in Forbes magazine articles. Suddenly, this startup feels much
more solid. Industry experts have apparently put their trust in this company,
so now it seems more legit and viable. Now, I just wanna interject a quick point
here. Even though we're grouping these social proof methods into neat psychological
constructs, the reality is that any and social proof method might work on several of
these cognitive constructs. For example, client logos might touch on both our desire
to fit in and our reverence for authority. Another thing to note is that many of
these methods should be researched even more in terms of why and how they work.
Some of the recommendations I'm discussing here are very supported by research, while
others are more like norms that have been established among professionals who work in
these spaces. Those are just some things to keep in mind here. Okay, so let's look
at our fourth construct here, dealing with the fact that we're afraid of missing
out. Yes, FOMO. So the basic mechanism here is that we recognize scarcity.
Of course, scarcity scarcity does not require a social element, you could be all
alone in the desert with no water to drink, and it doesn't require that other
people have drank up all the water. However, very often when we experience a sense
of scarcity, especially when it's being designed into an experience, it is often
being evoked socially where our own interests are being pit against the perceived
interests of others. So, let's look at the social proof method of "bomo" signals
using crowds. Imagine that there's some cool new device you want, maybe it's a
gaming console or a VR headset. You arrive before the store opens and you are
already seeing a long line of people who are presumably after the same thing that
you are. This gives you a feeling of scarcity and it's all the more important for
you to get your hands on the things that you're after. Now, we've already discussed
crowds before, however, crowds can be used in a couple of different ways. They can
be used to show that something is popular, but they can also be used to show that
something is running out or limited. Okay, so that's FOMO signals using crowds.
Well, how about FOMO signals using metrics? Imagine you're shopping for a pair of
running shoes and you find a pair that's perfect for you, and you figure that you
might get around to buying it sometime this week. But then you see in bright red
text, only three left in stock. So you hurry up and buy them so that you don't
miss out. We discussed usage metrics earlier, but just like With crowds,
they can be used to show popularity and /or scarcity. The recommended phrases to use
here are things like limited time only or only five rooms left in the case of
booking a hotel room for the day. Now much of this borders on manipulation, which
should be avoided. But it can also be used as a way of being courteous to your
users, letting them know that things might not be around forever. Another very
related social proof method would be FOMO signals from real time usage data.
Imagine that you're buying concert tickets. While you're on the website, you see 22
others are currently viewing this event. So now it feels like there's a crowd of
people who are clawing after the same thing that you're after. So you hurry up and
buy it. We're using real -time usage data here. This method brings the urgency to
life even more by providing a moment -by -moment reporting of reality. Okay,
so now we arrive at the final psychological construct in our discussion on social
proof today, and that is the topic of our imagination. Similar to the last
principle, the one dealing with scarcity. This is another mechanism that does not
inherently require a social element. However, it is often evoked socially.
We can understand it like this, our willingness to pursue a certain path into the
future often depends on our ability to imagine taking that path.
And it's easier to imagine ourselves if we can watch someone else doing it. Many of
the relevant methods here have already been discussed, so now we're going to look at
them through a slightly different lens. For example, when you view that testimonial
for a fitness program, not only does it help you relate to the person giving the
testimonial, but it also helps you imagine yourself doing it and succeeding at it.
Or recall that user -generated content might involve peers talking about their
experiences, and this might help you imagine yourself doing it. A client logo showing
a company similar to yours using the service helps you imagine a reality where your
own company is successfully using it. As a final example, let's look at the social
proof method of case studies. Imagine you want to hire a company to redo your
branding on your website, and you're worried that your logo, your branding, and your
website are too bare bones and underdeveloped, but then you stumble across a small
agency that shows before and after examples with beautiful images and well -written
content. This agency showcases their work in the form of case studies of clients
that are similar to you, so now it's easy for you to imagine yourself also having
a successful engagement with them.
To wrap things up, over the past two episodes on social proof, we've covered a lot.
In part one, we looked at the history of social psychology and how it shaped what
we now know as social proof. In this second part, we broke it down into five key
psychological drivers. One, we relate to other humans. Two, we want to fit in.
Three, we trust experts. Four, we are afraid of missing out.
Five, our imagination helps us take action. These drivers explain why social proof
works. We respond to stories, social signals, and shared experiences because they tap
into how our minds are wired. We also explored how to use social proof in design,
whether it's testimonials, expert endorsements, client logos, or user -generated content.
Each method works best when it feels real and when it feels relevant and respectful.
The goal here isn't to trick users, it's to guide them with clarity, trust,
and connection. So I'll end with a note that builds on that last point. Social
proof has often been used as a tool for manipulation, to steer people toward things
they don't need, and sometimes even things that may harm them. But it doesn't have
to be that way. We can imagine ways to leverage the insights given to us from the
rich history of social psychology. As design psychologists, we can choose to flip the
script. We can use social proof, not as a tool for manipulation, but as a tool for
connection, a way to help people recognize what might matter to them because they
see it mattering to others like them. Not pressure, not persuasion, but a it's
signal that there's something valuable here and that maybe it'll work for you too.