Why we like some people at our first meeting

Last weekend, I had a virtual friend visiting from abroad, accompanied by his friend “let’s call him Mr A” whom I had never met before. After being introduced, Mr A and I started talking as if we had known each other for years. Our conversation moved smoothly from shared interests to places we had visited, and even ranting about social media influencers who don’t seem to influence anyone. By the end of the evening, I felt certain that Mr A and I would become friends. We simply had so much in common.

Most of us have experienced this instant connection. One shared joke, a familiar hobby, or even a mutual irritation can make a stranger feel strangely familiar. Psychologists call this the similarity – attraction effect — our natural tendency to like people who resemble us in some way. This can be understood through three ideas: proximity, resonance and similarity.

Proximity suggests that we tend to connect with people we encounter often, even by chance. Resonance refers to that feeling of being “on the same wave length,” when conversation flows effortlessly. Similarity, perhaps the strongest factor, describes sharing elements of background or identity — for example, two people who both studied abroad and slip naturally between Arabic and English because it feels easier to express certain ideas that way.

A recent study from Boston University offers a deeper explanation for why these fast friendships form — and why we sometimes distance ourselves from people just as quickly. Researchers propose a concept called self-essentialist reasoning, the belief that each of us has a deep inner “core” that defines our values, interests and personality. When we see ourselves this way, we often assume that others are shaped by similar inner qualities.

The study found that when people believe in this inner essence, they are more likely to think that a single shared interest reflects a deeper similarity. If someone enjoys the same music, shares the same opinion, or even guesses the same number of dots on a page, we may subconsciously conclude, “They’re like me.” This sparks trust, warmth and an immediate sense of connection.

The reverse is also true. If someone disagrees with us — about politics, a book, a movie, or even a trivial preference — we may quickly assume they are fundamentally different, incompatible, or unlikable.

What’s more surprising is that the effect held even when the similarity was meaningless. In one experiment, participants were simply asked to estimate how many blue dots appeared on a screen. Even in this trivial task, people who believed in an inner essence felt more connected to someone whose estimate matched theirs.

This research suggests that our instinctive judgements — positive or negative — may be based on very little information. A single comment, shared hobby, or moment of disagreement can lead us to sweeping assumptions about who someone is at their core.

In a world where polarisation and quick judgements are becoming more common, this serves as an important reminder. Shared interests help us bond, but they do not define the entirety of a person. And one disagreement does not reveal someone’s whole worldview.

Perhaps the next time we meet someone who isn’t “like us,” we can pause before rushing to conclusions. First impressions matter — but they are not the whole story. People are far more complex, layered and surprising than a single conversation — or a single similarity — can ever reveal.