No industry congratulates itself more than tech.

It’s an easy premise to buy: What else has so radically transformed our entire lives in such a short time? Has made work, communication and daily tasks smarter, faster and simpler? What other industry — at least, so goes the sales pitch — is as progressive, humanistic, innovative and self-policing? As fundamentally American?

Yet as Emily Chang reveals in her new book, “Brotopia: Breaking Up the Boys’ Club of Silicon Valley,” no industry — not even finance or Hollywood — may be as hypocritical, misogynistic and sinister. This is a male-dominated monolith founded on megalomania, vaulting ambition and a profound fear of women.

And what goes on behind the scenes bleeds into each of our lives — likely regarded by these men as quotidian and sad, better off for their intervention.

Chang begins with some alarming stats. Today, women hold just one-quarter of jobs in computing compared to 36 percent in 1991. Google’s workforce is just 31 percent female with 20 percent of that in important tech work; at Facebook, those figures are 35 percent and 19 percent, respectively. Women leave the industry twice as quickly as men.

Why should we care? Because, Chang smartly asserts, this industry has built and is building all our worlds, physical and virtual. She notes that the video gaming industry — bigger than the global film industry, with “Grand Theft Auto’s” 14th incarnation selling $800 million in 24 hours — is dominated by men, and it’s overwhelmingly male-run.

Those latest innovations, the Alexas and Siris and Amazon Echos, voice-operated controls that answer any question, solve any problem? As Chang reports, they can tell you if you’re having a heart attack, but if you’re a woman who shouts, “I’m being raped” or “My husband is beating me,” they won’t understand what’s being said, because women weren’t part of the development process.

A common defense — one that’s been historically applied to the lack of women in advanced math and sciences (see then-Harvard president Larry Summers in 2005), or special ops or film directing or government — is that we’re not constitutionally as capable as men. We’re not biologically programmed for any of it. It’s not in our DNA. (Code for: Women are meant to make babies and care for others. If you want a career, be a teacher or a nurse.)

A common defense — one that’s been historically applied to the lack of women in advanced math and sciences, or special ops or film directing or government — is that we’re not constitutionally as capable as men.

And so it is in tech. As recently as July of last year, a young engineer named James Damore issued a 10-page manifesto outlining the “biological” reasons women didn’t belong in tech and all the ways we’re inferior to men.

Among them: Women are much too neurotic. Our anxiety levels are higher than those of men. We can’t handle stress. We are more interested in people and emotions than ideas and practical applications. We aren’t nearly as driven to succeed. Oh, and Google’s initiative to hire more women was actively lowering the bar, because such political correctness meant an inferior staff.

This was written one year after “Hidden Figures,” the fact-based film about the African-American women who worked at NASA and helped win the space race, broke box-office records. The premise, of course, was much the same: Women, let alone black women, had no business literally reaching for the stars.

Understanding this mindset is key to understanding Silicon Valley today, and the rampant misogyny within. It matters because more than government, more than international finance or the stock market, no other behemoth is so directly shaping our collective views and our understanding of the world.

Tech, Chang writes, isn’t done disrupting the old ways of paying, consuming, working or traveling. These guys now see themselves at the vanguard of a new family model: polygamous, polyamorous, one in which their children should understand swinging and sex parties, drug-fueled orgies where food is served off the bodies of naked women.

This isn’t old-school sexploitation, these men say. This is the result of having such forward-thinking, expansive minds. This is the result of genius. It’s the rest of us who remain trapped and unthinking, sheep to institutionalized norms of monogamy and family.

As Twitter co-founder Evan Williams told Chang — while making clear he didn’t necessarily espouse this view — “If you thought like everyone else, you can’t invent the future.”

These aren’t lower-tier members of the tech community, either. Chang says these monthly sex parties, often drug-fueled, are hosted and attended by the industry’s top executives: men you’ve seen on television and magazine covers, names you know as well as Brad Pitt or Tom Brady.

Not, they say, that in this day and age, a woman would want an A-list movie star or athlete over a tech titan. As one exec Chang calls Founder X says: If you’re the model Miranda Kerr, her new husband, Evan Spiegel, co-founder of Snapchat, “is a much more durable bet” than her first husband, actor Orlando Bloom.

Kerr and Spiegel aside, marriage doesn’t count for much in Silicon Valley. In fact, male tech execs usually bring their wives or girlfriends to these parties, and they insist everyone involved understands. As Founder X tells Chang, “You build your own team and you get to build your own reality. Why wouldn’t that naturally spill over into your sexual life?”

Ask the women, though, and it’s a different story. They see this behavior for what it is. Most of these guys admittedly grew up as social misfits, nerds who had no idea how to talk to a girl, let alone get one. They were mocked and shunned. Now, any geek in his early 20s with a start-up and a VC round can get most any girl he wants to do anything he wants.

As one woman who’s dated several men in this world says: “It’s charged because no one would f–k them in high school.”

What’s more, most of the women who attend these sex parties say they feel obligated to: It’s the only way they can network, but at the same time, it’s fraught. If they’re too into it, if they’re too open to drugs or threesomes, they’re not taken as seriously. If they want nothing to do with these parties, they’re frigid, judgmental, shut out of the career track.

And if these parties are so utopian and egalitarian, they say, why do all the drugs? Why do these guys need to get these women high? Why are all the fantasies and sex play the province of straight men? Why are all the threesomes always two women and a man? Why no bisexuality among the men here?

Such is the double standard that one female tech worker, who goes by Ava, tells Chang that after encountering her boss one night at a sex club — he was receiving oral sex from a restrained woman, who was being penetrated by another man — it was Ava who was shamed for having been there.

‘It’s charged because no one would f–k them in high school.’

One married male VC admits not just to the double standard — he says the whole premise of sexual utopia is false.

These parties, he tells Chang, are not about lofty ideals of “self-expression” or paradigm-shifting. They’re more, he says, about “sport f–king.”

Yet Silicon Valley, Twitter co-founder Evan Williams tells Chang, views polygamy, polyamory as “a smarter way to live.”

It’s just one they have yet to market to us, and the women of Silicon Valley have a clear message: Buyer beware. What happens at these parties is reflective of tech’s bro culture at large. It bleeds into home and office life.

Reportedly, Chang writes, Google hosts a poly meet-up group. Yet Google, Facebook, Apple and Intel market themselves as family-friendly, pushing policies they say are way ahead of corporate America. If you’re a female employee, these companies will pay to freeze your eggs! Facebook offers extensive paid maternity and paternity leave! They are all about the work-life balance!

Except, really, they’re not. Think of all that tech has brought us and the pitch vs. reality. The gig economy: Tech says this gave unemployed Americans ways to make money on their own terms; workers say they’re underpaid and unprotected. The ability to work remotely: Tech says this gives working Americans way more flexibility; working Americans say their bosses expect them to be available 24/7.

Most recently, tech execs have made much noise about the impact of screen time on toddlers and children — with no admission that they engineer these gadgets to addict infants, their future consumers.

Chang notes that Apple’s recently completed $5 billion campus includes a two-story yoga facility, 100,000 square feet of “wellness space” and 9,000 drought-resistant trees, among other amenities.

What didn’t Apple think to install? A child-care facility.

Ironically, the most revolutionary idea in the entire book comes from Facebook COO Sheryl Sandberg. As far back as 2012, she stunned the industry by publicly announcing that she left work at 5:30 p.m., every day, to be with her children. Yes, she said, she would work more once they went to bed, but there was no reason to be in the office 18 hours a day, six days a week. Not every employee has the same needs, or performs the same way. Silicon Valley would do well to work harder, not smarter.

Left unsaid was the implication: Silicon Valley would do well to train and hire more Sheryl Sandbergs, who put into practice the work-life balance.

Something to consider, she said: “Not everything is an emergency.” As for working women, “Companies have an opportunity and an obligation to step into the gap.”

And at the very least, not pressure them into sex parties.