We like to think that animals, including humans, follow the crowd. Think of a flock of pigeons taking off from the city square together or the recent frenzy over labubus. If most of the group does something, surely the individual will copy.
This process has given rise to human culture, from our diets and the tools we use to eat to language and art.
But what if it’s more complicated? What if the deciding factor isn’t just what the majority is doing, but how strongly you already feel about it?
That’s the question our team, the Animal Cognition Research Group in the Department of Psychology at the University of Alberta, set out to test in zebra finches. Zebra finches are small, highly social songbirds that breed in colonies in the Australian outback. In our laboratory, they build dome-shaped nests year-round using coloured string.
Sometimes obsessive colours preferences
Individual males, the nest builders in the species, show stable colour preferences. Some strongly prefer blue. Others lean yellow. Some are almost obsessive about it.
However, if a male who prefers one colour enters a population where most nests are built from another colour, will he conform? And more specifically, does the strength of his original preference matter?
To answer that, we ran a three-phase experiment. First, we measured each male’s colour preference by presenting him with blue and yellow strings and recording how long he interacted with each. This allowed us to calculate which colour he preferred and how strongly. A bird spending 95 per cent of his time with a blue string is very different from one splitting his time 60/40.
Next, we placed that male and his female partner into a population where four other pairs were incubating eggs in completed nests. These nests varied systematically. In some groups, all four nests matched the male’s preferred colour. In others, most, or all, contradicted it. The observer male could watch these nests and their occupants for several days. Finally, we returned him to his own cage, provided both colours of string and allowed him to build.
Here’s what we found
Males with weak initial preferences were more likely to conform. If most nests they observed were built from their non-preferred colour, they were more likely to switch and use that colour themselves. Males with strong initial preferences largely ignored the majority. They saw the same information. They had the same opportunity to copy, but they didn’t.
Interestingly, many birds did notice the social information. When the majority of the population used a focal male’s non-preferred colour, these males were more likely to first touch that colour when they began building. They paid attention. But noticing is not the same as changing.
In building his nest, what mattered most was the interaction between the social environment and the strength of the male’s original bias. This distinction, between acquiring social information and actually using it, is critical. Animals may observe what others are doing without necessarily acting on it. That gap may help explain why evidence for conformity in animals has been mixed.
In human psychology, we see something similar. People with strong pre-existing beliefs are less susceptible to social influence. Present the same evidence to two individuals with different prior convictions and you may get very different outcomes. The stronger the initial attitude, the more resistant it tends to be.
We found the same pattern in birds. The stronger the bias, the less likely the individual was to conform. Zebra finches are not forming political opinions about string colour. But the underlying mechanism is strikingly similar: strong preferences can act as filters, buffering individuals against social influence. That has important implications for how culture forms and persists.
Individual choices build culture
Conformity is one of the processes that stabilizes cultural traditions. If newcomers reliably adopt the majority behaviour, group patterns become entrenched. But if some individuals resist, because their personal biases are strong, traditions may spread more slowly or fail to take hold.
This suggests that individual variation is not just background noise. It may actively structure how information moves through a population.
Most animal conformity studies have focused on foraging. We examined nest construction, an ecologically important, fitness-relevant behaviour. Nest design influences reproductive success, so the balance between personal preference and social information likely carries real consequences.
Even in this high-stakes context, birds did not blindly follow the crowd. Some conformed. Some didn’t. And the difference depended, in part, on how strongly they felt to begin with.
One of the most powerful aspects of this project was seeing how a seemingly simple question — whether the birds would copy others — unfolded into something much more nuanced. We had to distinguish between seeing, learning and doing. And we had to account for bias strength, not just bias direction.
Culture emerges at the group level, but it is built from individual decisions. Each bird chooses which string to pick up and whether to add it to the nest. Sometimes, even when the entire room is blue, a yellow-loving bird sticks with yellow.
That tension, between the pull of the group and the pull of the self, turns out to be central to understanding how traditions form, persist and sometimes fail. And it may help us think about conformity in our own species, too.