1장
The Gender Data Gap: How a World Designed for Men Shortchanges Half of Humanity
In 2019, Caroline Criado Perez's "Invisible Women" sent shockwaves through the public consciousness, exposing how our supposedly gender-neutral world is actually designed for men. The book won the prestigious Royal Society Science Book Prize and sparked global conversations about gender bias in design, medicine, and public policy. Endorsed by figures ranging from Melinda Gates to Hillary Clinton, this groundbreaking work reveals how the systematic exclusion of women from data collection creates a world where everything from smartphones to medical treatments to urban planning fails women in ways both frustrating and dangerous. As The Guardian noted, "The thoroughness of Criado Perez's research is staggering," making this book essential reading for anyone who cares about equity, innovation, or simply understanding why the world works the way it does.
2장
The Default Male: How "Gender-Neutral" Became "Male Unless Otherwise Specified"
The assumption that men represent the human default runs deep in our collective consciousness. From Aristotle's view of females as "deformed males" to modern evolutionary theories that positioned "Man the Hunter" as the driver of human development, we've consistently treated the male experience as universal. This bias persists even in supposedly objective scientific research. When studies claim to reveal universal human traits-like our species' evolved tendency toward lethal violence-they often ignore that such violence is overwhelmingly male (96% of homicide perpetrators worldwide).
This male-unless-otherwise-indicated thinking extends across multiple fields. Cave paintings long attributed to male hunters are now thought to be mostly created by women. Viking skeletons with female pelvises were assumed male when buried with weapons, despite evidence of battle-scarred female skeletons across Eurasia showing up to 37% of Scythian women and girls were active warriors. When female remains challenge assumptions, the evidence is questioned in ways male remains never are-archaeologists routinely find more male skeletons than female ones in grave sites, a statistical impossibility for human populations.
Language itself reinforces this bias. The "generic masculine" in various languages, where male terms supposedly include women, consistently fails to be read as gender-neutral. Studies show when masculine terms are used generically, people recall more famous men, perceive professions as male-dominated, and suggest male candidates for jobs. Women apply less frequently and perform worse in interviews for jobs advertised with masculine language. Even stereotypically female professions like "beautician" are suddenly perceived as male when generic masculine language is used.
This male-dominated culture has normalized male experience as universal while female experience is treated as niche. Films about women's struggles are criticized for not covering "important" topics like war. Women's achievements are routinely forgotten or attributed to men-from Virginia Wade's Wimbledon victory to the US women's soccer team's multiple World Cup wins. Female composers like Fanny Hensel had work published under her brother Felix Mendelssohn's name, while Hertha Ayrton noted that errors attributing women's work to men "have more lives than a cat."
When institutions like the Bank of England claim "objective" selection criteria for representation, they perpetuate this bias-requirements like "broad name recognition" disadvantage women whose contributions have been systematically erased. This creates a vicious cycle where the historical gender data gap both causes and is reinforced by supposedly neutral standards that are actually designed around male patterns of success.
3장
Can Snow-Clearing Be Sexist? The Hidden Biases in Urban Planning
It began with a joke in Karlskoga, Sweden in 2011, when officials implementing gender-equality initiatives questioned whether snow-clearing could possibly be sexist. Traditional snow-clearing prioritized major traffic arteries before pedestrian walkways and bicycle paths-a seemingly neutral policy that actually affected men and women differently due to their distinct travel patterns.
Data consistently shows women are more likely to walk and use public transport-women make up two-thirds of public transport passengers in France and over 60% in Philadelphia and Chicago-while men are more likely to drive and dominate access to household cars, even in Sweden.
These differences extend to travel purposes. Men typically have simple commuting patterns, while women engage in "trip-chaining"-multiple interconnected journeys reflecting their disproportionate responsibility for unpaid care work. Women do 75% of the world's unpaid care work, resulting in complex travel involving school drop-offs, medical appointments, and shopping.
When Karlskoga switched to prioritizing pedestrians and public transport users, they discovered an unexpected benefit: cost savings. Pedestrian injuries in icy conditions cost twice as much as winter road maintenance, with women making up 69% of those injured. In Stockholm, accidents decreased by half on cleared pedestrian-cycle paths.
The problem stems from male-dominated transport planning that focuses on "mobility related to employment" while dismissing care-related travel as non-essential. Government spending reflects this bias: road-building receives lavish funding while feminized transport like buses faces cuts. Even transport surveys often intentionally omit shorter pedestrian trips that women disproportionately make.
Women's fear in public spaces is rooted in reality, not paranoia. Despite severe underreporting (90-96% of incidents go unreported across cities like London, New York, and Baku), evidence confirms women's concerns are legitimate. Sexual violence on public transport is widespread-90% of French women and two-thirds of Brazilian women have experienced harassment while in transit. From Rio to Los Angeles, women have been raped on buses while drivers continue their routes.
Transit agencies-dominated by male leadership-frequently deny gendered safety concerns exist. When agencies do implement security measures, they typically focus on wrong areas-installing cameras on buses when women feel most vulnerable at bus stops. Women prefer preventative solutions like security guards rather than CCTV, which men prefer. Simple, cost-effective solutions exist: digital timetables to avoid long waits, transparent shelters, better lighting, and request stops for night buses.
4장
The Long Friday: Women's Invisible Work and Its Economic Impact
On October 24, 1975-what Icelandic men called "the long Friday"-90% of Iceland's women went on strike. They performed no work-paid or unpaid-forcing men to cope without the invisible labor that kept the country running. Supermarkets sold out of ready meals, children flooded offices, and schools operated at reduced capacity. Twenty-five thousand women rallied in Reykjavik, remarkable in a country of just 220,000. The impact was profound: Iceland passed the Gender Equality Act the following year, elected the world's first democratically elected female head of state five years later, and now tops global gender equality rankings.
The strike exposed how "working woman" is a tautology-all women work, but much of it goes unpaid. Globally, women perform 75% of unpaid work, spending 3-6 hours daily compared to men's 30 minutes to 2 hours. This imbalance starts in childhood and persists regardless of women's income contribution. Even when men increase their unpaid work, they choose enjoyable activities like childcare rather than routine housework or elder care. While women have joined the paid workforce, men haven't reciprocated with domestic labor-women simply work longer hours total. Women enjoy significantly less leisure time than men, and what little they have is more fragmented.
This care burden impacts women's health, with studies showing married women recover worse from heart attacks than single women, while husbands create an extra seven hours of housework weekly for their wives. Women face higher rates of work-related stress, anxiety and depression than men in every age range, with women 53% more stressed overall. Working over 55 hours weekly significantly increases women's risk of mental health problems but doesn't have the same effect on men.
The gender disparity in work-hour thresholds narrows only for "unencumbered" workers with minimal care responsibilities. Women accommodate care responsibilities by working part-time (42% of UK women versus 11% of men), earning less per hour and often working below their skill level. The gender pay gap widens to 33% in the twelve years after childbirth as women's careers stagnate. Over a lifetime, this results in dramatically lower earnings - up to $285,000 less for German women with one child by age 45 compared to childless women working full-time.
5장
The Myth of Meritocracy: How Brilliance Bias Undermines Women
Despite evidence showing brilliance bias can be corrected in children by including female scientists in textbooks, it's much harder to fix once ingrained in adults. This bias is particularly problematic as it's being hardwired into algorithm-driven recruiting.
Computer science exemplifies brilliance bias. Steven Levy's 1984 book "Hackers" portrayed an exclusively male culture while failing to connect the field's open misogyny with women's absence. Teachers perpetuate this bias by defining aptitude through male-typical behavior like obsessive all-night coding sessions, ignoring how girls might express interest differently due to socialization.
Ironically, coding was originally women's work. Women were the first "computers" doing complex math by hand, and programmed ENIAC, the first fully functional digital computer in 1946. Women dominated programming through the 1950s, with Grace Hopper comparing it to planning dinner-requiring patience and detail management that made women "naturals."
As employers realized programming required advanced problem-solving, they began training men instead. They developed seemingly objective hiring tools that were covertly biased, using multiple-choice tests focused on math skills men were more likely to have studied and personality profiles seeking antisocial "loner" traits. These biases are now resurfacing in AI-driven hiring algorithms like Gild, which ranks candidates by "social capital" measured through online activity, disadvantaging women who have less leisure time due to unpaid care work.
Most troublingly, these algorithms remain proprietary and secret, creating a double gender data gap: first in the knowledge of algorithm designers, second in society's understanding of how discriminatory these systems are.
Companies like Google attempt to fix gender disparities by making women more like men rather than questioning male-default systems. When women didn't self-nominate for promotion at the same rate as men, Google held workshops to encourage them to do so, ignoring that men of average intelligence typically overestimate their abilities.
Evidence-based solutions exist when organizations actually examine data. Quotas have been found to "weed out incompetent men" rather than promote unqualified women. Changing job ad language from aggressive, competitive terms to emphasizing teamwork and innovation dramatically increases female applicants. Blind recruitment systems like GapJumpers have increased hiring from underrepresented backgrounds from 5% to nearly 60%. And accountability through data collection and monitoring committees has effectively eliminated pay gaps.
6장
The Henry Higgins Effect: Workplace Design and Women's Safety
The chapter opens with Facebook COO Sheryl Sandberg describing her difficult pregnancy while working at Google, including nine months of morning sickness, swelling throughout her body, and feet that grew two sizes larger. After struggling to walk across Google's large parking lot, she finally asked founder Sergey Brin for designated pregnancy parking, which he immediately approved, noting he'd never considered it before. This exemplifies how workplace data gaps persist until senior women experience issues firsthand. Modern workplaces remain full of design problems for women, from heavy doors to office temperatures that are calibrated for men's metabolic rates (five degrees too cold for women on average).
While workplace fatalities have decreased significantly over the past century, serious injuries among women workers are actually increasing. This disparity stems from occupational research traditionally focusing on male-dominated industries. For example, care workers like Beatrice Boulanger receive little training for heavy lifting despite often moving more weight than construction workers or miners, leading to serious injuries like Boulanger's shoulder replacement.
Workplace safety standards are based on "Reference Man" - a 70kg Caucasian male aged 25-30 - despite women having different immune systems, hormones, body size, skin thickness, and higher body fat that affects chemical absorption. This creates dangerous exposure standards for women. We urgently need sex-disaggregated data on chemical exposure, including reproductive status, and measurements focused on women themselves rather than just fetuses.
Equipment designed for men causes injuries for women across industries. In agriculture, tools are too heavy, long, or improperly balanced for women's typically smaller hands and different strength distribution. Construction tools show similar problems - from cement bags and bricks sized for male hands and strength to wrenches that women can't properly grip. Even in industries with good safety records, women suffer higher rates of sprains, strains and nerve conditions because equipment isn't designed for their bodies.
Most personal protective equipment (PPE) is designed for European and American male bodies, with employers often simply buying smaller sizes rather than female-specific designs. Surveys show 74% of PPE is designed for men, with only 29% of women wearing female-specific equipment. This "unisex approach" creates serious safety hazards - safety harnesses don't fit female chest, hip and thigh proportions; dust masks designed for "standard" US male faces don't seal properly; and ill-fitting boots and gloves can cause accidents.
7장
One-Size-Fits-Men: How Product Design Excludes Women
The chapter examines how products designed around male body proportions disadvantage women, despite claims of gender neutrality. From pianos to smartphones, the "one-size-fits-men" approach creates professional barriers and health risks for women.
Pianist Christopher Donison observed that the world divides into those with larger and smaller hands-with women having significantly smaller hands on average. Standard 48-inch keyboards with 7.4-inch octaves disadvantage 87% of adult female pianists. A 2015 study of 473 pianists found all twelve internationally renowned pianists had handspans of 8.8 inches or larger, including the two women who had unusually large 9-inch and 9.5-inch spans. Female pianists suffer disproportionately from injuries-78% develop RSI compared to 47% of men. Donison's 7/8 DS keyboard solution transformed his playing, allowing correct fingerings and proper technique, yet the piano world remains strangely reluctant to adopt this adaptation despite studies confirming its benefits.
Modern smartphones average 5.5 inches, comfortable for men's one-handed use but problematic for women whose hands are barely larger than the devices themselves. Despite women being more likely to own iPhones than men, manufacturers remain fixated on large screens. When researcher Zeynep Tufekci tried documenting tear gas use during Turkish protests, her oversized Google Nexus prevented one-handed photography-something she'd "seen countless men with larger hands do all the time."
Voice recognition, suggested as an alternative to typing, is itself male-biased-Google's speech recognition is 70% more accurate for male voices, creating safety issues in cars where women report systems only responding to men. One woman's 2012 Ford Focus voice-command system only listened to her husband despite him being in the passenger seat. When another woman called Buick for help, she was told "point-blank it wasn't ever going to work" and to "get a man to set it up."
Rather than fixing the technology, industry representatives like ATX's Tom Schalk blame women's voices, suggesting they need "lengthy training"-if only they were "willing" to submit to it. Tatman refutes this, citing research showing women actually have "significantly higher speech intelligibility," produce longer vowel sounds, and speak slightly more slowly than men, while men demonstrate higher rates of speech disfluency and "sloppy" pronunciations.
When women are in car crashes, they're 47% more likely to be seriously injured than men because cars are designed around male bodies. For decades, crash-test dummies represented only the 50th percentile male (1.77m tall, 76kg). Despite researchers advocating for female dummies in the early 1980s, the US only introduced them in 2011. However, these "female" dummies are problematic-they're often just scaled-down male dummies that don't account for women's different muscle distribution, bone density, and vertebrae spacing.
8장
The Drugs Don't Work: Medical Research's Gender Gap
Medical research has revealed profound sex differences throughout the human body. Sex differences exist in every tissue and organ system, affecting disease prevalence, course, and severity. The heart's mechanical workings differ between sexes, as does lung capacity. Women who smoke the same amount as men are 20-70% more likely to develop lung cancer. Autoimmune diseases affect women three times more frequently than men, possibly because females evolved stronger immune responses to protect fetuses. Women develop higher antibody responses to vaccines with more frequent adverse reactions-researchers have even proposed sex-specific influenza vaccines.
Despite this overwhelming evidence, women remain severely underrepresented in medical research. Women made up only 25% of participants in heart failure trials between 1987-2012, and despite representing 55% of HIV-positive adults in developing countries, they comprised just 19.2% of antiretroviral study participants. The systematic exclusion of women from trials intensified after the thalidomide scandal of the 1960s, when the FDA issued 1977 guidelines excluding women of childbearing potential from drug trials.
Some researchers still insist biological sex doesn't matter, claiming female bodies are "too complex," "too variable," or "too costly" to test-despite studies showing greater variability in male mice on numerous markers. When women are included in trials, they're typically tested during their early follicular phase when hormone levels are lowest, ignoring how hormonal fluctuations affect drug efficacy and safety throughout the menstrual cycle.
The failure to sex-disaggregate data has life-or-death consequences. A 2014 review of cardiac resynchronization therapy devices (CRT-Ds) revealed that while individual studies showed no sex-specific differences due to low female participation, meta-analysis uncovered a critical disparity: the 150-millisecond threshold for implantation worked for men but was 20 milliseconds too high for women. Women with electrical waves between 130-149 milliseconds experienced a 76% reduction in heart failure or death with the device-yet guidelines excluded them.
Women face disproportionate risks from medications due to gender-neutral dosing that ignores fundamental physiological differences. The FDA's 2004-2013 database showed women experiencing over 2 million adverse drug reactions compared to less than 1.3 million for men. Women are more likely to be hospitalized following adverse reactions, and 80% of drugs recently removed from market caused more problems in women. Despite obvious sex differences in metabolism-women eliminate acetaminophen at 60% of men's rate-most drugs maintain gender-neutral dosages, putting women at risk of overdose.
9장
Yentl Syndrome: How Medicine Fails Women
In this chapter, Criado Perez explores how women are misdiagnosed and poorly treated unless their symptoms conform to male standards-a phenomenon called "Yentl syndrome." Heart disease exemplifies this problem: while commonly perceived as a male condition, cardiovascular disease has been the leading cause of death in US women since 1989. Women from lower socio-economic backgrounds are 25% more likely to suffer heart attacks than comparable men, and women-particularly young women-are more likely to die following heart attacks.
Women's heart attacks are frequently missed because they often don't present with the "Hollywood heart attack" symptoms of chest and left-arm pain. Instead, women-especially younger ones-may experience stomach pain, breathlessness, nausea and fatigue. These symptoms are misleadingly labeled "atypical" despite their frequency in women, leading to dangerous underestimation of risk. A 2005 study found only one in five physicians across specialties knew more women than men die from cardiovascular disease annually. NHS England guidelines requiring "acute cardiac sounding chest pain" for referral to specialist heart-attack centers disadvantage women, possibly explaining why 75% of those receiving emergency PPCI treatment are men.
Women's heart attacks may be mechanically different from men's, making standard diagnostic technology unsuitable. Traditional angiograms identify obstructed arteries, but women often have heart attacks without such obstructions. This leads to women with chest pain being discharged with "non-specific chest pain" diagnoses despite their risk-some have suffered heart attacks or strokes shortly after discharge.
Women's physical pain is routinely dismissed as emotional or psychosomatic. Conditions like endometriosis take an average of 8-10 years to diagnose despite affecting one in ten women worldwide. The bias starts early-parents perceive higher-pitched baby cries as female and rate them as indicating less discomfort. Instead of believing women's pain, we label them "hysterical" (from the Greek word for womb), "crazy," or "emotional." This dismissal has historical roots in women being institutionalized for behaviors outside feminine norms. Today, women are 2.5 times more likely to be prescribed antidepressants than men, often when they're not actually depressed. Studies show women reporting pain receive sedatives or antidepressants while men receive pain medication-despite women having higher pain sensitivity and experiencing many chronic pain conditions at significantly higher rates than men.
Female-specific health issues remain chronically under-researched. Premenstrual syndrome affects 90% of women but has five times fewer studies than erectile dysfunction. Over 40% of women with PMS don't respond to available treatments, yet researchers are denied grants because "PMS does not actually exist." Period pain affects up to 90% of women with pain described as "almost as bad as a heart attack," yet treatment options remain limited and poorly understood. When a 2013 study found sildenafil citrate (Viagra) provided "total pain relief" for period pain with no side effects, researchers couldn't secure funding for larger trials because review panels "did not see dysmenorrhea as a priority public health issue."
10장
The Solution: Closing the Female Representation Gap
The solution to the gender data gap is straightforward: we must close the female representation gap. When women occupy positions of power and influence, they simply don't forget that women exist.
The evidence is compelling across all fields. Women in the film industry are more likely to employ women. Female journalists more frequently center women's perspectives and quote women. Female authors overwhelmingly write about female subjects (69% compared to just 6% of male biographers). As female history faculty in the US rose from 15% to 35% between 1980-2007, those specializing in women's history increased tenfold from 1% to 10%. Female academics assign more female authors to their students.
Women also interpret data differently. As Sandi Toksvig recounts, a female anthropology professor questioned whether a marked antler bone with 28 notches was "man's first calendar" by asking what man needs to track 28 days - suggesting it was likely a woman's creation.
In politics, women like Maria Miller forced the UK government to make Brexit compatible with the Equalities Act, protecting women's rights. Women are leading efforts to close the gender data gap - research shows studies are more likely to include gender analysis when women are among the authors, especially as lead authors. Women established the first parliamentary group for women's health in the UK and spearheaded global initiatives like Data2x to address the gender data gap.
Even in disaster relief, women fill crucial gaps left by male-biased systems. After Hurricane Maria devastated Puerto Rico, women led community organizing efforts - collecting data by wading into flooded areas, setting up kitchens, rebuilding roads, distributing supplies, and creating legal aid societies.
Three key themes define women's relationship with the world. First is the female body's invisibility in design, creating a world where women don't fit well-from cars and workplaces that injure us to drugs that don't work for us. The second theme is the paradoxical hypervisibility of female bodies when it comes to male sexual violence. The third and most significant theme is unpaid care work. Women worldwide shoulder far more than their fair share of this essential labor.
Failing to collect data on women's lives naturalizes sex discrimination while simultaneously rendering it invisible. Women face the irony of being hypervisible as a subservient class yet invisible when it comes to being counted. The persistent excuse encountered throughout this research was that women are "too complicated to measure." The consensus seems clear: women are treated as abnormal and atypical. But this isn't reality-it's just easier and cheaper to pretend men represent everyone. Simple doesn't reflect reality.
