It’s easy to think of behaviour as a matter of personal choice. But a lot of research suggests something more complicated. The way we think, decide, and act is shaped by the cultural environments we’re part of. And at the same time, the small things we do every day quietly reinforce and shift that culture.

Culture shapes how we think

Most of us are comfortable with the idea that culture influences behaviour. What’s less obvious is that it also shapes how we think in the first place.

For a long time, psychology assumed cognition was largely universal. Early cognitive research was mostly done on what are now called WEIRD samples (Western, Educated, Industrialised, Rich, Democratic), often other psychology students. From that, it was easy to assume that perception and reasoning worked the same way everywhere.

That assumption hasn’t held up.

There’s now strong evidence that the way we notice, interpret, and process information depends on the environments we grow up in. A well-known example is the Müller-Lyer Illusion, where two lines appear to be different lengths even though they’re identical. What’s interesting isn’t the illusion itself, but that not everyone sees it the same way. Studies with Indigenous communities, including people from the Murray Islands in Australia, found they were less affected by it. One explanation is that people who grow up surrounded by rectangular buildings are more likely to interpret visual cues in terms of depth.

Culture doesn’t just shape perception; it also shapes what we pay attention to. Take the opening ceremony of the Beijing Olympics in 2008. What appeared to be a solo performance by one young girl was later revealed to involve two: one visible on stage, the other singing behind the scenes. In the US, reactions often focused on the individual, especially concerns about self-esteem – the idea that one girl was not considered “good enough” to perform alone. In China, the same situation was more often understood in terms of the group – two girls working together as a team to successfully represent China.

Same event, different interpretation. Not because people care about different things in a simple sense, but because they’re used to seeing the world through slightly different lenses.

Culture shapes what we do

If culture shapes how we think, it also shapes how we behave, often without us realising it.

In everyday life, we don’t constantly weigh up every decision. We rely on what feels normal. Those “default scripts” often come from watching what other people do.

I remember working in road safety research and being struck by how many speeding drivers weren’t particularly risk-seeking. They were just following traffic. If everyone else was going a bit over the limit, they did the same. It then became easy to justify – checking the speedometer too often feels distracting, enforcement seems unlikely, and it feels safer to move with the flow.

The risk doesn’t disappear, but it fades into the background once the behaviour feels normal.

You see the same pattern elsewhere. People are more likely to litter in places that are already messy. In classic experiments by Solomon Asch, participants gave answers they knew were wrong simply because others had done so first. Households reduce their energy use when they find out their neighbours are using less, regardless how much energy they used in the first place.

In all of these cases, behaviour is guided less by deliberate reasoning and more by a simple question: what are other people doing?

Behaviour shapes culture

The relationship goes both ways.

When behaviours are repeated often enough, they start to feel normal. Over time, they become expectations. That’s essentially how cultural norms form.

There’s also evidence that behaviour can shape beliefs. When people do something repeatedly, they tend to adjust their thinking to match. It’s not just that beliefs drive actions – actions can reshape beliefs as well.

This matters when we think about change. We often assume that if people understand something better, they’ll behave differently. But in practice, shifting behaviour first can be more effective. Once something becomes common, it starts to feel right, and eventually it becomes part of how people think.

A continuous loop

Culture and behaviour aren’t separate. They feed into each other all the time.

Culture influences how we see things and what feels normal. That shapes what we do. And what we do, especially when repeated across many people, becomes part of culture.

Seen this way, everyday actions carry a bit more weight. Small things don’t just reflect the world around us, they help maintain it or change it.