Pattern and Perspective
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Why Does Seeing Someone Else Buy Something Make Us Reconsider Buying It?

08 September 2026 - Sibongile Borokini (Author)

You weren't planning to buy it. Maybe you'd seen the product before. Maybe you'd even decided it wasn't worth the money. You were perfectly comfortable with your decision. Then your friend bought it. Suddenly, you're looking at it differently. You start wondering whether you made the right decision. You look up reviews. You compare prices. You think about whether you could actually afford it. Somehow, a product that didn't seem particularly interesting yesterday has found its way into your mind.

Nothing about the product changed.

So what did? The answer is... US.

Our purchasing decisions rarely happen in isolation. We like to think of ourselves as independent consumers, carefully evaluating what we need and what we can afford. But the thing is, human beings are social creatures, and other people's behaviour often becomes part of the information we use to make our own decisions. Sometimes, we follow because we're uncertain. Sometimes, because we see someone else enjoying something we want. And sometimes, because watching someone move ahead makes us wonder whether we're falling behind. This is where an ordinary shopping decision becomes much more interesting.

We Use Other People as Information

Imagine you're considering buying a product you've never used before. You don't know whether it's actually good. You don't know whether the quality matches the price. You don't know whether you'll regret buying it. There is a gap between what you know and what you want to know. When we don't have enough information, we tend to look outward.

In their 1955 research on conformity, psychologists Morton Deutsch and Harold Gerard distinguished between two forms of social influence. One involves the pressure to fit in with a group. The other, known as informational influence, happens when we use other people's behaviour as evidence about what is true or appropriate (Deutsch and Gerard, 1955). That distinction matters when we shop.

If someone we trust has already bought something, their decision can become a small piece of evidence for us. Maybe it's actually good. Maybe they know something I don't. Maybe I was wrong to dismiss it. Their purchase hasn't proved that the product is good but it has reduced some of the uncertainty surrounding the decision.

Funny enough, this isn't unique to shopping. We do something similar in all kinds of situations where we aren't sure what to think or do. When our own information is incomplete, other people's behaviour becomes another source of information, even when that information isn't necessarily reliable.

Solomon Asch's famous conformity experiments demonstrated just how powerful group influence can be. Participants sometimes changed their own judgments in response to an obviously incorrect group answer (Asch, 1951). The experiment wasn't about shopping, but it revealed something important about human judgment, that our perception of reality isn't completely independent of the people around us.

So when a friend confidently buys something you've been uncertain about, their decision can carry more psychological weight than you might expect.

We Don't Just Hear About Other People's Experiences. We Watch Them.

There is another layer to this. We don't necessarily need to experience something ourselves to become interested in it.

Albert Bandura's theory of observational learning suggests that people can learn by watching what happens to others. We can observe someone's behaviour and the outcome that follows without experiencing that outcome ourselves (Bandura, 1977).

Think about what this looks like in everyday life. Your friend buys a new phone. You watch them use it. They tell you how much they love the camera. You see how smooth it works. You notice people complimenting it. You haven't used the phone but you have already experienced a version of the story. You have watched someone else receive the reward and that can make the product feel more desirable.

This is one reason social proof is so powerful in marketing. Robert Cialdini identifies social proof as a major principle of persuasion. When people are uncertain about what to do, they often look at what other people are doing (Cialdini, 2021). Retailers have turned this tendency into an entire language of persuasion. Five-star ratings. Customer reviews. "Bestseller" labels. "X people bought this today."

These signals aren't simply there to provide information. They communicate something deeper, other people chose this!

And sometimes, that's enough to make us reconsider whether we should choose it too.

The Internet Has Made the Pattern Impossible to Ignore

Online shopping gives us an almost constant stream of other people's decisions. We can see how many people reviewed something. We can see what they thought about it. We can see how highly they rated it. We can even see indications that other people are buying the same thing while we're looking at it.

Research suggests that these signals matter. A meta-analysis by Qiu and Zhang examined 156 studies, 214 effect sizes and 69,006 observations and found that several aspects of online reviews (including their positivity, volume and ratings) were significantly associated with purchase intention. The emotional tone of reviews was the strongest individual factor (Qiu and Zhang, 2024). In other words, what other people say about a product can influence how likely we are to want it but the effect isn't limited to what people say they intend to buy. Research has also connected online reviews to actual sales.

A meta-analysis by Floyd and colleagues examined 26 studies and found that both the tone and quantity of online reviews were associated with increases in retail sales. The relationship was particularly strong for products that were expensive or complicated to evaluate (Floyd et al., 2014). That makes intuitive sense when you think about it.The more costly a decision feels, the more uncomfortable uncertainty becomes. If you're buying a packet of pens, you probably don't need 500 strangers to convince you. If you're spending thousands on a laptop, phone, appliance, or another major purchase, suddenly other people's experiences feel much more valuable.

Their decisions help us answer a question we can't answer through the product alone, "Will I regret this?!"

Sometimes, It's Not About the Product at All!

Here's where things get more complicated and interesting. Sometimes we see someone buy something and don't simply think, That product must be good. We immediately think: Hey, I want that. Most of the times, underneath that desire is comparison.

A study by Van Tran, Nguyen and Nguyen examined how upward social comparison, which is seeing someone who appears to have something better than we do, can stimulate impulse buying. One mechanism involved benign envy, an aspirational form of envy in which another person's possession can make us want to obtain something similar ourselves (Van Tran, Nguyen and Nguyen, 2023). This distinction is important. We don't always buy because we resent someone. Sometimes, we buy because seeing them makeYour friend gets the new phone, you think about your old phone that needs to be adjusted or slapped before it charges. Someone buys a beautiful outfit and you suddenly notice how tired you are of your wardrobe. Someone upgrades their car and your perfectly functional car starts feeling old.

The object hasn't changed. The comparison has. It's important to note that the effect isn't necessarily the same for everyone. Van Tran, Nguyen and Nguyen (2023) found that self-esteem played a role in the relationship between upward social comparison, benign envy and impulse buying, suggesting that people may differ in how susceptible they are to comparison-driven purchases. This is one reason two people can see exactly the same social media post and walk away with completely different feelings. One person thinks, Nice. Another thinks, I need that.

The difference may have very little to do with the product itself.

Maybe We're Not Buying the Thing

There is a strange psychological shift that happens when someone else makes a purchase. Before they bought it, we were probably evaluating the product. After they bought it, we may start evaluating ourselves. Do I have enough? Am I doing well enough? Am I missing out? Should I have this too? Am I behind? This is where consumer behaviour begins to overlap with identity.

Gleb Tsipursky has written about the influence friends can have on our shopping decisions, drawing on research into how behaviours can spread through social networks. His argument is that the people close to us can influence what we buy because their choices can create subtle pressure to keep pace (Tsipursky, 2020). Perhaps that's why certain purchases feel more persuasive when they come from people we know. A stranger buying something online is information. A friend buying it can feel like a comparison.

The person isn't just saying, this product exists.

Their purchase can unintentionally communicate, this is something people like us can have and that changes the psychological meaning of the purchase.

The Pattern Is Bigger Than Shopping

It's easy to look at all of this and conclude that we're simply being manipulated but that would be too simple.

Looking to other people isn't a flaw in human behaviour. In many situations, it's useful. Other people can genuinely provide information we don't have. Their experiences can help us avoid bad decisions. Their recommendations can save us time and money. The problem isn't that we pay attention to other people. The problem is that we don't always notice when their decision has quietly become part of ours.

That distinction matters.

The next time you suddenly want something because someone else bought it, perhaps the more interesting question isn't, "Why do I want this?" but it is rather

"Did I want this before I saw them have it?" Maybe the answer is yes. Maybe you were already considering it or maybe their purchase introduced a completely new desire that wasn't there before.

Neither answer makes you irrational. It simply reveals something deeply human about the way we make decisions. We observe. We compare. We learn. We imitate and sometimes without realizing it, someone else's choice becomes a mirror in which we reconsider our own.

That might be the pattern worth noticing.

References

🧠 Brain Trigger

Ever stood in a supermarket with two queues and thought, “I'm definitely choosing the faster one” only to watch the other queue move while yours barely does? Well, blame that on basic probability. If there are four queues and you randomly choose one, there's only a 1-in-4 chance that you've picked the fastest queue. That means there's a 75% chance that at least one of the other queues will be moving faster than yours. So when you start wondering, “Why is everyone else's queue moving faster?” You're not imagining it. The odds are literally stacked against you. You are not unlucky, you are just OUTNUMBERED 😂

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