My first job after college was at a stuffy, old-fashioned, centuries-old New York publishing house. The dress code, at least for women, was a disciplinary-writeup-waiting-to-happen, especially for a tattooed, fuschia-haired wannabe punk with a newly minted liberal arts degree and a tiny paycheck.
Some of the highlights: No sleeveless blouses. No t-shirts or casual shirts. Pantyhose must be worn with skirts. Skirts could be no shorter than two finger-widths above the knee. No open-toed shoes or sandals. Heels could not be higher than two inches. These (and I'm sure others I've since forgotten) were all codified in our employee handbook.
The dress code for men? "Business casual," which was decidedly not explained to the extent the code was for women, seemed to mean khaki pants, oxford shoes or loafers and what seemed like an endless variety of shirt options: golf, rugby, button-down.
Half the time, I was so nervous that my group's administrative assistant would find something wrong with my outfit that I spent most of my work day trying to avoid her, lest I get written up, which happened more times than I'd like to admit. Not much time left for productivity.
My next job, at a small upstart publisher in Arizona, had a one-line dress code: "Employees must wear undergarments." This was added to the employee handbook only after an unfortunate incident involving an unsuspecting FedEx driver getting flashed by a former employee when she stepped outside to sign for a package and met with a rogue gust of wind.
Thankfully, old-fashioned dress codes are increasingly rare, especially in tech, where you're more likely to encounter teams dressed in t-shirts and hoodies than a pages-long list of What Not to Wear. And while this is fantastic, it's still a struggle for women, people of color and gender-non-conforming people in the workplace.
Emily Peck, writing for Huffington Post, uses Sheryl Sandberg and Mark Zuckerberg as an extreme example of the double-standard still at work in corporate America: While Zuckerberg can get away with the same gray t-shirt day after day, Peck uses Sandberg's footwear to illustrate how women, especially, aren't taken seriously in the workplace unless they conform to society's beauty standards.
And it's worse for people of color and for gender-non-conforming people who don't fit either mold. For instance, black women and men being told their natural hair isn't "professional" or "polished" enough for the workplace. Uh, what? The point is, being judged on appearance, race, gender or ethnicity is the underlying problem - sometimes dress codes are only a symptom of the larger issue that must be overcome and are used to enforce the white, male 'standard.' The idea is that the workplace default, the norm, is a white, middle-class male; anyone else is an anomaly.
Whether or not a dress code (or a uniform) impacts productivity in the workplace is an ongoing argument that doesn't seem likely to resolve any time soon. What I think all of this comes down to is allowing your workforce to decide for themselves how they're most comfortable and what will allow them to do their best work.
That's a bit simplistic and general, I know. In certain industries it's impossible. In fields such as law, finance, politics and government and sales you must "look the part" to a certain extent. But in technology, should it matter? I don't think so.