How much money do you make? According to my income tax forms, I made a little over $30,000 in 2016. I'm a freelance writer, a gig that is unstable and probably unsustainable and silly; I might make more than that this year, or I might make less. (I'm getting $350 for this story.) I've found that it freaks people out when you talk about money like this. Even in an era where nearly everyone shares nearly everything, salary figures feel intimate, embarrassing, personal.

When I posed this question on Facebook, no one replied in public. Many friends were comfortable sharing their income with me privately—a teacher admitted they made $45,000, a scientist said $60,000—but no one would come out and tell the world their number.

"I hesitated to share because I thought, Oh no, so low, how embarrassing," one friend said in a response to a follow-up post. "Then after the comments I thought, On no, it's too high, it's like I'm bragging, and I was fascinated by why I even care."

"It's actually a very weird thing because I earn almost exactly the median household (not individual) income for the city of Los Angeles, yet I have certainly felt very insecure about money at times," said another friend.

This insecurity we all feel, this need for secrecy, divides us in invisible ways. If we're interested in creating a more equitable society, or just getting compensation we deserve, we need to talk about money. We need to talk about who makes too little, we need to talk about who makes too much, and how much we make personally.

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Claudia Hammond is a broadcaster for BBC 4 and the author of Mind Over Money: The Psychology of Money and How to Use It Better. She told me it's obvious why employers don't want employees to talk freely about income—everyone knowing what everyone else gets paid would make any inequities obvious. Workers might individually demand better pay. They might even unionize. When employees don't know that they're being taken advantage of, they can't complain about it.

Knowing our colleagues' and friends' salaries would also help us realize how pernicious racial and gender pay disparities are. There are women who get paid less than men for doing the same jobs, and they won't realize it unless they—and the men who work with them—are transparent about their salaries.

We might know all this and still balk at talking about our number.

"People that research money have found that it very difficult," Hammond told me. "Many have found that people are happier to talk to a complete stranger about their sex lives than they are about how much they earn."

(When I asked Hammond how much she made, her reply was: "I could tell you, but the evidence suggests I won't.")

In the past, this taboo has been explicitly enforced by the management class. Hammond's research uncovered a vague news report about a "big American company" after World War I that sent a memo telling employees not to discuss their wages. According to the possibly apocryphal story, workers came in the next day with giant signs around their necks showing their salaries. Silencing actions like that led, in 1935, to a provision in the National Labor Relations Act explicitly allowing employees to discuss wages with one another; more recently, Barack Obama signed an executive order prohibiting federal contractors from retaliating against employees who disclosed their salaries.

But employers don't need to be ham-fisted in their efforts to block talk of salary. Bosses can create a veil around salaries by signing contracts and giving raises behind closed doors. They don't actually need to say anything to silence money talk. Like my Facebook friends, many workers are embarrassed they're paid too much or too little; they fear mockery or shame or pity. We've allowed discussions about pay to become increasingly fraught affairs because we're worried about the social implications when we open our mouths.

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"People want to get along. The worry is that somebody you're friends with will all of a sudden treat you differently," said Brad Brummel, adviser at the job search engine CareerBliss.com and associate professor of organizational psychology at the University of Tulsa. "My friend has his salary posted next to his name online so you can search, and if he goes to a friend's birthday party and gives a middle-of-the-road gift, they might look at that and go, 'Huh. That's all he wants to give us given what he makes?'"

(Brummel told me, because I asked, that he gets $75,000 a year through his professorship and another $25,000 through "grants, service roles, and consulting.")

We avoid these conversations because they're uncomfortable, they're gauche, whatever—and as a result, judgements about the income of others are allowed to seep into the unexpressed margins.

"We try to think of our society as a meritocracy, that we're not supposed to judge people on the basis of their gender, skin color, sexual orientation, the whole list of things," said Brummel. "But one of the things that's socially acceptable is to make judgements on the basis of the job people choose, and how much it's valued."

There are ways to figure out roughly how much money other people make. Freelancers like me can post anonymous information about how much they've been paid by who at WhoPaysWriters.com. You can find career-specific averages at sites like PayScale or CareerBliss. But you don't know that your friend has been working at the same job for a decade with no raise, or that your other friend is going into massive credit card debt to pay for what looks like a comfortable lifestyle. You don't know how much less your teacher aunt makes than your bond trader uncle; if you did, you might ask why that was.

The ongoing Fight for $15 campaign on behalf of fast food workers' rights has been successful at least in part because it has a specific number attached, one that reminds everyone how little these workers make. There are other, more subtle protests against the status quo, like Maria Bamford using her commencement address at the University of Minnesota to discuss exactly how she negotiated her speaking fee, teaching her liberal arts crowd to value their work.

Asking questions about money feels intimate because it is an intimate thing. But it's that lack of intimacy that is keeping us from knowing what inequities our friends, families, and co-workers are fighting. We can go through life knowing how little the waiters serving our food or the teachers educating our children are paid. This is a problem. Let's talk about money.

An earlier version of this story misspelled Brad Brummel's name.