Are the choices we make in our daily lives a result of our own innate desires or a lemminglike drive to fit in?

When it comes to what to wear, people’s decisions are usually a mix of both. Fashion is undeniably about staying on trend and in step with those around you. But for many people, it’s also about expressing their own preferences and individuality.

Fashion may seem like a trivial subject, but Jeff Galak, a professor at Carnegie Mellon University’s business school, says it provides an excellent measure for examining how people are influenced by those around them and the lengths to which people go to conform. After all, Americans spend a huge amount of time and billions of dollars each year to keep up to date with fashions.

In a recent paper, Galak and three co-authors seek to examine how social conformity works by looking at one aspect of fashion that they can easily quantify: the height of women’s shoes. The researchers examine the height of shoes that more than 1,800 women purchased at an online luxury clothing retailer across America.

In particular, they look at women who move from one location to another in the United States and analyze whether the height of the shoes they bought changed after they moved to be more similar to what women in their new area were purchasing. In total, they tracked nearly 15,000 shoe orders made over nearly five years.

Past psychological studies have shown that the urge toward conformity is so powerful as to almost be irresistible. And Galak and his co-authors found that people who moved tended to demonstrate some tendency toward conformity, changing the height of the heels they purchased to be more in line with the purchases that people in their new homes were making.

But there was a crucial difference: That tendency to conform differed depending on the wealth of the places the women were coming from and the wealth of the places they were moving to. People conformed much more when they moved to a place with higher socioeconomic status, as the chart below shows. It didn’t matter whether heels were higher or lower in the higher-class destination — in fact, they were about evenly split on that measure, Galak says.

“When women move from lower-income area to a higher-income area, they pretty much took on the preferences of women around them,” Galak said. “On the other hand, when they moved from a wealthier area to a less wealthy area, what we found is that women pretty much stuck with their preferences.”

In other words, when a woman moved to a higher-status area, she was more likely to try to adopt the fashion and practices of people there. When a woman moved to a lower-status area, she was more likely to retain her old behavior, perhaps as an effort to be unique.

Galak says these data are consistent with some theories in sociology, that what we perceive as “taste” generally flows downward, from those that society considers to have high status down to those with lower status. And in the United States, that status is inextricably linked with money.

Many of the mass market fashion trends that become popular start with high-fashion houses that cater to the wealthy and to celebrities — what’s known as the “upper class theory of fashion.” It’s an elite-driven system that Meryl Streep’s fashion maven character, Miranda Priestly, describes perfectly in “The Devil Wears Prada.”

This isn’t always true of course — sometimes street style filters up, as in the case of grunge or hip-hop fashions. But for the most part, people ascribe to the fashions of those above them on the socioeconomic ladder.