Earlier this week, a group of women in their 50s showed up at the Cannes Film Festival in France and were turned away. The reason? They weren't wearing high heels. One woman's partial foot amputation prevented her from following the black tie dress code.

The festival director later apologized and then further irritated critics by asking why people don’t get mad about fashion expectations at the Oscars. Some film stars angrily spoke out. “We shouldn’t wear high heels, anyway,” British actress Emily Blunt declared at a news conference. “I prefer wearing Converse sneakers.”

Emily Blunt. (Bertrand Langlois/AFP)

But, if Blunt prefers wearing Converse sneakers, why didn’t she rock a pair on the Cannes red carpet (as her male co-stars sported flat soles)? Why don’t we all wear Converse sneakers on life’s red carpets?

The Cannes fiasco is an extreme manifestation of the pressure to wear heels in professional and formal settings, to look polished by conventional standards.

Heels, as many wearers know, present a physical problem. They can harm your feet and your spine and your general ability to stay upright. But they’re still nearly institutionalized in white-collar workplaces and Hollywood parties.

Marlene Reid, a podiatric surgeon in Chicago and spokesperson for the American Podiatric Medical Association, said her patients who regularly wear heels often push through discomfort for months, coming to her with torn ligaments and stress fractures. “My male patients come in as soon as they have pain,” Reid said. “My female patients ignore pain and just deal with it. They feel pressured to look feminine and want to wear heels everywhere — not just the workplace.”

The Spine Institute of Florid

Let's be clear, though: Some people just like wearing heels for the sake of wearing heels. They're probably not thinking about social pressure at a Bloomingdale's sale.

The psychology of heels has long been complex — and not uniquely related to pressures facing women. They represent perceptions of attractiveness that affect both women and men.

People surveyed by researchers at California State University, Northridge, reported feeling much more confident when sharply dressed. “Putting on formal clothes makes us feel powerful, and that changes the basic way we see the world,” Abraham Rutchick, an author of the study and a psychology professor, told the Atlantic.

A study by economists Daniel Hamermesh and Jeff Biddle used survey data to investigate a possible link between appearance and income. Subjects were lumped into three brutally named groups, determined by survey respondents' assessment of their beauty: below average, average and above average.

The "plainness penalty" was 9 percent, Hamermesh and Biddle found — meaning a person with “below average” appearance made 9 percent less per hour than someone with an average appearance. The "beauty premium," meanwhile, was 5 percent, after controlling for variables like education and experience.

Height may also influence our paychecks. Each inch above average may be worth $789 more per year, according to a study in the Journal of Applied Psychology. Researchers examined the earnings of 8,500 participants in the U.S. and Britain, controlling for gender, age and weight. Findings suggest someone who is 6 feet tall earns, on average, nearly $166,000 more over 30 years than someone who is 5 feet 5 inches.

The world sends mixed signals, however, when it comes to heels. Social outcomes apparently depend on the setting.

A study in the Archives of Sexual Behavior, for example, found men on the street were more willing to assist women in stilettos. Researchers instructed female participants to approach strangers and ask for directions. Responses varied drastically by footwear: 83 percent of the men aided women in towering pumps -- and only 47 percent agreed to help the same women if they donned something closer to Birkenstocks.

The story changes in an office setting. Less traditionally feminine clothing triggered more positive responses from hiring managers in a 1985 study. Researchers found female interview subjects were significantly more likely to be viewed as strong job candidates if their clothes appeared more “masculine.”

Young women today remain as conflicted as they were 30 years ago about the way they should present themselves at the office, said Maura O’Neill, a business professor at the University of California, Berkeley. She has studied gender perceptions in the workplace and advised college students launching their careers.

“I once had a suit, an incredible power suit — and I wore it on the days that I needed to show up as wonder woman,” she said, laughing. Heels give some women the same confidence boost. The uncomfortable dichotomy: What some consider devices of objectification, others see symbols of feminine strength — I can wear pink pumps and close more deals than you.

“My advice is: Show up who you are and own that,” O’Neill said. “Heels or flats.”