By Jackie McGlone

“OKAY, I’M OFF TO STOP BREXIT,” declares Caroline Criado Perez, shrugging on her jacket, tucking a curtain of curly hair into a beanie and striding confidently out of the clamorous cafe, where we meet, into the “dead zone” of London around Millbank and Horseferry Road.

As I watch the 34-year-old writer, broadcaster, award-winning feminist campaigner and activist depart, accompanied by her faithful wee dog, Poppy, I think, “If anyone can do it, Criado Perez can.” After all, she’s campaigned since 2012 to improve women’s representation in the media, co-founding the website the Women’s Room, after hearing only male experts holding forth on consecutive days on the Today programme about teenage pregnancies and breast cancer. The website, which collects female professionals available for interview, now has a roster of more than 2,500.

Brazil-born, Oxford University-educated, Criado Perez is most famously responsible, however, for getting a woman’s face printed on an English banknote -- Jane Austen -- then campaigning vociferously to get a statue of a woman -- suffragist Millicent Fawcett holding a banner inscribed, “Courage calls to courage everywhere” -- erected in Parliament Square last year. She has also forced Twitter to revise its procedures for dealing with extreme abuse after being subjected to systematic and sustained abuse online, including rape and murder threats. (A man and a woman were eventually jailed in January 2014 for their attacks on her.) In 2013, she was the recipient of the Liberty Human Rights Campaigner of the Year Award and was awarded an OBE in 2015.

Now, she’s published an impressive book, Invisible Women: Exposing Data Bias in a World Designed for Men, in which she details how women have been routinely left out of the data in which the most important decisions -- in disasters, in hospitals, in factories, on our roads -- are made. As a result, she reveals, women are dying unnecessarily. She details jaw-dropping information on everything from seat belt and air bag design -- they were designed on male crash dummies which explains why the seat belt on our Mini used to throttle me -- to the fact that women are up to 50% more likely to be misdiagnosed following a heart attack since they do not suffer the “Hollywood heart attack,” chest and left arm pains.

Women’s symptoms tend to be stomach pain, breathlessness, nausea, fatigue. Yet heart failure trials tend to use only male participants. “I find this so shocking,” says Criado Perez. “We have known about this for 20 years and we are still not accounting for it. It sums up the whole bloody thing. That’s what made me most angry while I was writing the book.”

Criado Perez backs up her research with a wealth of mind-bending statistics, including 69 pages of endnotes “in very small typeface,” because she knew that men would take to Twitter -- as they have done -- and try to debunk her research. This is therefore a serious book written with flair and wit. For instance, she’s come up with The Henry Higgins Effect (Why can’t a woman be more like a man? grouches the phoneticist in My Fair Lady) when she writes, among other things, about the higher rate of pelvic stress fractures suffered by women in the British Army because they are using equipment designed around the male body. Meanwhile, female police officers wear stab vests designed for the male physique.

As for tech culture, the average smartphone, she points out, is too big for most women’s hands and it doesn’t fit in our pockets. Speech-recognition software is trained on recordings of male voices. Only 3.3% of video games feature female protagonists, although equal numbers of men and women play them. The list is endless; the message an important one. “The gender data gap,” she argues, “is both a cause and a consequence of the type of unthinking that conceives of humanity as almost exclusively male... and that the dangers of being relegated to, at best, a sub-type of men, are as real as they have ever been.”

Her brilliant book, which one reviewer has noted “uses data like a laser,” has been three years in the researching and writing and, I tell Criado Perez, I have never been so angry as when I finished reading it. On its publication, she urged her 58,000 Twitter followers to join her “in FURY.” So here I am and I am FURIOUS.

“Good! I am delighted to hear it because I want to have all women absolutely furious,” she exclaims, adding that she’s blown away by the response to the book, which she readily acknowledges some people will hate. After an extract was published in a magazine, however, her Twitter feed has been inundated with an avalanche of examples from women on the impact of the gender data bias on their lives.

“It was enraging researching and writing the book, just because of how pervasive the issue is -- basically it’s about forgetting that women actually exist and how damaging that is to women’s health and wellbeing. The solution is so simple -- start asking women. That is the takeaway of the book. I feel quite hopeful that it can happen especially with all these stories coming in on Twitter.” What has made writing the book so worthwhile, she explains, has been the number of women thanking her for making them realise that there is not something wrong with them because, for example, they can’t reach the grab rail on a train or if they too feel in danger of strangulation by car seat belt.

Three themes kept popping up as she was writing. “Women’s [unpaid] care work, violence against women and female bodies. How to thread those through without being repetitive was a real feat of painful brainwork. It was definitely not an easy book to write. I care about it such a lot. It’s about my life as a woman so in a way I’ve been researching it for 34 years. The answer is so simple -- collect data on women, speak to women, hire women. Women don’t forget women! Medical researchers have to to get serious, they have to stop saying women are too complicated and get women on their team. Half the world doesn’t know what the other half needs.”

When Criado Perez was 15, her parents split up. Her childhood was spent travelling the world -- her international businessman father is Argentinian -- and her mother, Ali, gave up her nursing career to raise three children. After the divorce, she made a new life for herself in her fifties and went to work for Medecins[acute accent on first e] Sans Frontieres[grave accent on first e]. Criado Perez has said she sees her mother as a fantastic role model not only for herself but for all women.

Was she a spirited, plucky child? “I certainly wasn’t a feminist; I wasn’t political. I didn’t grow up with a burning desire to change the world -- I do now! I’ve always been loud and opinionated, which I had to be growing up in a household with two older brothers. I guess being half Argentine, I have a bombastic, Latin edge. I became a feminist when I was 25 and at university. Until then every time I met a new person I felt I had to make them realise I was intelligent and not trivial because I was a woman. How terrible was that!

“Then I read a book by the linguist Deborah Cameron, in which she discusses that the word ‘man’ is used by default for ‘human’. I realised that when I heard that word I pictured a male figure -- lawyers, doctors, scientists, philosophers, artists, professors, a genius... all men. I grew up with all these men in my head, not questioning, always picturing them. What was I thinking or rather not thinking? It makes me so angry that I grew up thinking so little of my sex.”

How does she find the energy, the courage to battle on? “I run, I used to box but now I do yoga and I have many friends, although I now live alone [with Poppy]. I’m on a What’s App group on which friends share things that happen to us, stuff that’s said to us -- so you always know you’re supported.”

And what’s next for this warrior woman? “Well, there’s another campaign coming. But, you know, a campaign takes over your life; it takes so much time,” she sighs, then grins widely, “First, though, there’s Brexit!”

Invisible Women; Exposing Data Bias in a World Designed for Men, by Caroline Criado Perez (Chatto & Windus, £16.99).