We grab lunch together pretty regularly at my workplace. I'm a software engineer at one of the world’s biggest tech companies, and while not mandatory, it's the company norm to eat with your teammates weekly—if not daily—at a cafeteria in our building.

Conversation tends to be as routine and predictable as the lunching itself. "What'd you do over the weekend?" usually spans Monday and probably Tuesday. "Plans for this weekend?" is a Thursday to Friday favorite.

But sometimes, on Wednesdays—too far from either end of the week—we run out of things to say (after exhausting the obvious topic of work itself). What then? Software engineers are not known for our conversational prowess. We fumble around, spinning the conversational rolodex in a sort of lunch-topic roulette, and usually end up somewhere safe and uncontroversial, like movies or travel.

But sometimes we don't.

One Wednesday, lunch-topic roulette landed on police brutality. At my company, where only 1% of engineers are black, the sole black engineer at the table recounted a time when he narrowly avoided wrongful arrest. He then compared it to one of the many recent cases of excessive police force against people of color.

The table balked at his accusation.

"How can you be sure this is racism?" one white male colleague protested. "You can't generalize anything from an isolated incident."    

How can you be sure this is racism?

Another time, lunch-topic roulette landed on sexism in tech. I explained that while rare for me personally, sexism does happen at my company, where only 18% of engineers are women. In fact, recently, an engineer had infuriatingly mansplained to me programming concepts that you’d learn in an “Intro to Computer Science” class.

My male colleagues frowned.

"I don't know if that's sexism. Maybe he's like that to everyone."

Trying to bolster my point, I shared another incident from years ago that was even more egregious. While visiting my team, on which I was the only woman, one male engineer from another office pretended I didn't exist. He spoke solely to the men, sharing his fondness for scouting for "cute chicks" working late—presumably single women he could corner after other colleagues had gone home.

This, too, was met with skepticism.

"Is that sexism though?"

A table of kind-hearted software engineers provides one of the safest conversational environments. You can reveal your nerdiest hobbies to a rapt audience. You can make the lamest puns to polite chuckles, if not genuine belly laughs.

Why, then, are software engineers often terrible allies to people of color, women, and other marginalized groups?

I suspect it lies in the way we're trained to think about problems.