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Every card in Who Knew carries a short source tag and a card number. Find the card number below for the full reference.

Career & Finance

CF01 Kray, L.J., Kennedy, J.A. & Lee, M. (2024). Now, women do ask: A call to update beliefs about the gender pay gap. Academy of Management Discoveries.
CF02 Equal Credit Opportunity Act of 1974 (United States).
CF03 OECD (2025). Pensions at a Glance 2025. OECD Publishing.
CF04 Budig, M.J. (2014). The fatherhood bonus and the motherhood penalty: Parenthood and the gender gap in pay. Third Way.
CF05 CBS Statistics Netherlands (2025). Economic independence of women and men (‘economisch zelfstandig’: net income from work at least welfare level). 1977 figure: CBS historical series.
CF06 MooseMoney (2026). Survey of 639 Canadian adults on money and relationships (online, non-probability sample).
CF07 Fidelity Investments (2017). Money FIT Women Study; Fidelity Investments (2021). Women and Investing Study.
CF08 Exley, C.L. & Kessler, J.B. (2022). The gender gap in self-promotion. The Quarterly Journal of Economics.
CF09 See Womanship research.
CF10 McKinsey & Company and LeanIn.Org (2025). Women in the Workplace 2025.
CF11 PitchBook (2025). 2024 US All In: Female Founders in the VC Ecosystem. (All-female founding teams: 1.9% of 2024 US VC deal value.)
CF12 Otis, N., Delecourt, S., Cranney, K. & Koning, R. (2024). Global evidence on gender gaps and generative AI. Harvard Business School Working Paper 25-023.

Sex & Relationships

SR01 Frederick, D.A., St. John, H.K., Garcia, J.R. & Lloyd, E.A. (2018). Differences in orgasm frequency among gay, lesbian, bisexual, and heterosexual men and women in a U.S. national sample. Archives of Sexual Behavior.
SR02 Rosenfeld, M.J. (2018). Who wants the breakup? Gender and breakup in heterosexual couples. In D.F. Alwin, D.H. Felmlee & D.A. Kreager (Eds.), Social Networks and the Life Course. Springer.
SR03 Uloko, M., Isabey, E.P. & Peters, B.R. (2022). How many nerve fibers innervate the human glans clitoris? A histomorphometric evaluation of the dorsal nerve of the clitoris. Presented to the Sexual Medicine Society of North America; Journal of Sexual Medicine (abstract).
SR04 Pew Research Center (2020). A profile of single Americans.
SR05 Wang, W. (2018). Who cheats more? The demographics of infidelity in America. Institute for Family Studies. (General Social Survey data: 20% of ever-married men and 13% of ever-married women.)
SR06 Fidelity International (2019). Survey of 2,000 UK adults on finances and relationships.
SR07 Chong, J.Y. & Fraley, R.C. (2025). The long-term stability of affective bonds after romantic separation: Do attachments simply fade away? Social Psychological and Personality Science. (328 adults; full fade around 8 years, modelled.)
SR08 Netherlands, Act on the Opening Up of Marriage (2000). First weddings: Amsterdam City Hall, 1 April 2001.
SR09 See Womanship research.
SR10 Levin, R.J. & Wagner, G. (1985). Orgasm in women in the laboratory: quantitative studies on duration, intensity, latency, and vaginal blood flow. Archives of Sexual Behavior.
SR11 Centers for Disease Control and Prevention (2025). National Intimate Partner and Sexual Violence Survey (NISVS): 2023/2024 Intimate Partner Violence Data Brief.
SR12 Haupert, M.L., Gesselman, A.N., Moors, A.C., Fisher, H.E. & Garcia, J.R. (2017). Prevalence of experiences with consensual nonmonogamous relationships: Findings from two national samples of single Americans. Journal of Sex & Marital Therapy.

Fertility & Pregnancy

FP01 Quenby, S. et al. (2021). Miscarriage matters: the epidemiological, physical, psychological, and economic costs of early pregnancy loss. The Lancet.
FP02 Bianchi, D.W., Zickwolf, G.K., Weil, G.J., Sylvester, S. & DeMaria, M.A. (1996). Male fetal progenitor cells persist in maternal blood for as long as 27 years postpartum. Proceedings of the National Academy of Sciences.
FP03 World Health Organization (2023). Infertility prevalence estimates, 1990–2021. (Lifetime prevalence 17.5%.)
FP04 American College of Obstetricians and Gynecologists, with the American Society for Reproductive Medicine (2014). Female age-related fertility decline. Committee Opinion No. 589.
FP05 Jones, R.K. & Jerman, J. (2017). Population group abortion rates and lifetime incidence of abortion: United States, 2008–2014. American Journal of Public Health. (Lifetime incidence 23.7%.)
FP06 Pew Research Center (2024). The experiences of U.S. adults who don’t have children.
FP07 Ghalioungui, P., Khalil, S. & Ammar, A.R. (1963). On an ancient Egyptian method of diagnosing pregnancy and determining foetal sex. Medical History.

Motherhood & Family

MF01 Reczek, R., Stacey, L. & Thomeer, M.B. (2023). Parent–adult child estrangement in the United States by gender, race/ethnicity, and sexuality. Journal of Marriage and Family.
MF02 Buzard, K., Gee, L.K. & Stoddard, O. (2025). Who you gonna call? Gender inequality in external demands for parental involvement. NBER Working Paper. (Field experiment, about 80,000 US schools.)
MF03 Pew Research Center (2023). In a growing share of U.S. marriages, husbands and wives earn about the same.
MF04 US Family and Medical Leave Act of 1993 (unpaid leave only); Försäkringskassan, Swedish Social Insurance Agency: 480 days of parental benefit per child.
MF05 McGinn, K.L., Ruiz Castro, M. & Lingo, E.L. (2019). Learning from mum: Cross-national evidence linking maternal employment and adult children’s outcomes. Work, Employment and Society. (24 countries, about 50,000 adults.)
MF06 Catalano Weeks, A. & Ruppanner, L. (2024). Study of cognitive household labour among 3,000+ US parents, University of Bath and University of Melbourne. Journal of Marriage and Family.
MF07 Rohrer, J.M., Egloff, B. & Schmukle, S.C. (2015). Examining the effects of birth order on personality. Proceedings of the National Academy of Sciences.
MF08 Madigan, S. et al. (2024). Meta-analysis of parental sensitivity and child attachment security. Psychological Bulletin. (22,000+ parent–child pairs.)
MF09 Raphael, D. (1973). The Tender Gift: Breastfeeding. Prentice-Hall.
MF10 See Womanship research.

Emotional Well-being

EW01 Schumann, K. & Ross, M. (2010). Why women apologize more than men: Gender differences in thresholds for perceiving offensive behavior. Psychological Science.
EW02 Kumar, A. & Epley, N. (2018). Undervaluing gratitude: Expressers misunderstand the consequences of showing appreciation. Psychological Science; Kumar, A. & Epley, N. (2023). A little good goes an unexpectedly long way: Underestimating the positive impact of kindness on recipients. Journal of Experimental Psychology: General.
EW03 See Womanship research.
EW04 Cox, D.A. (2021). The state of American friendship: Change, challenges, and loss. Survey Center on American Life. (1990 figures: Gallup.)
EW05 Brooks, A.W., Gino, F. & Schweitzer, M.E. (2015). Smart people ask for (my) advice: Seeking advice boosts perceptions of competence. Management Science.
EW06 Deloitte Global (2025). Women @ Work 2025: A Global Outlook. (7,500 women in 15 countries.)
EW07 Clance, P.R. & Imes, S.A. (1978). The imposter phenomenon in high achieving women: Dynamics and therapeutic intervention. Psychotherapy: Theory, Research & Practice.
EW08 Trudel-Fitzgerald, C. et al. (2020). Social integration and exceptional longevity in the Nurses’ Health Study. Journals of Gerontology: Series B. (72,322 women; reported as 41% higher odds.)
EW09 World Health Organization (2025). Depressive disorder (depression): fact sheet.
EW10 See Womanship research.
EW11 Hochschild, A.R. (1983). The Managed Heart: Commercialization of Human Feeling. University of California Press.
EW12 See Womanship research.

Physical Well-being

PW01 National Institutes of Health Revitalization Act of 1993 (United States).
PW02 Ji, H. et al. (2024). Sex differences in association of physical activity with all-cause and cardiovascular mortality. Journal of the American College of Cardiology. (About 400,000 US adults. Men reached an 18% lower risk of early death at about 300 minutes of exercise a week; women reached the same at about 140.)
PW03 Endometriosis UK (2024). Diagnosis survey of 4,371 people: average 8 years 10 months; 47% saw their GP 10 or more times.
PW04 Penn et al. (2025). Price and prejudice: reimbursement of surgical care on male versus female anatomies. Journal of Women’s Health.
PW05 Wu, J. et al. (2016). Impact of initial hospital diagnosis on mortality for acute myocardial infarction: A national cohort study. European Heart Journal: Acute Cardiovascular Care. (Data from England and Wales.)
PW06 National Institutes of Health (2024). NIH Research Matters: why autoimmune disease is more common in women.
PW07 Dorani, F., Bijlenga, D., Beekman, A.T.F., van Someren, E.J.W. & Kooij, J.J.S. (2021). Prevalence of hormone-related mood disorder symptoms in women with ADHD. Journal of Psychiatric Research. (209 women, The Hague.)
PW08 Department of Health and Social Care (2022). Women’s Health Strategy for England. (Call for evidence, about 100,000 responses.)
PW09 Stephens, R., Atkins, J. & Kingston, A. (2009). Swearing as a response to pain. NeuroReport.
PW10 See Womanship research.
PW11 Czerny, V. (1895). Plastischer Ersatz der Brustdrüse durch ein Lipom. Zentralblatt für Chirurgie.
PW12 Women in Global Health (2021). Fit for women? Safe and decent PPE for women health and care workers.

Menopause & Ageing

MA01 Avis, N.E. et al. (2015). Duration of menopausal vasomotor symptoms over the menopause transition. JAMA Internal Medicine. (SWAN study.)
MA02 Kling, J.M. et al. (2019). Menopause management knowledge in postgraduate family medicine, internal medicine, and obstetrics and gynecology residents: A cross-sectional survey. Mayo Clinic Proceedings. (6.8% felt adequately prepared.)
MA03 Ellis, S. et al. (2024). The evolution of menopause in toothed whales. Nature.
MA04 Jakobsdóttir Smári, U. et al. (2025). Perimenopausal symptoms in women with and without ADHD: a population-based cohort study. European Psychiatry. (Icelandic SAGA cohort, 5,392 women.)
MA05 Stichting Farmaceutische Kengetallen (SFK) (2025), reported by NOS: 130,000 women aged 40–60 use hormone therapy for menopause, 40% more than a year earlier.
MA06 University of Michigan National Poll on Healthy Aging, with AARP (2018). Let’s talk about sex.
MA07 Alzheimer’s Association (2026). Alzheimer’s Disease Facts and Figures.
MA08 Koga, H.K. et al. (2022). Optimism, lifestyle, and longevity in a racially diverse cohort of women. Journal of the American Geriatrics Society. (159,255 women, Women’s Health Initiative.)
MA09 CIPD (2023). Menopause in the workplace: Employee experiences in 2023. Fawcett Society (2022). Menopause and the Workplace.
MA10 See Womanship research.

Grief & Loss

GL01 Rees, W.D. (1971). The hallucinations of widowhood. British Medical Journal.
GL02 Merrill Lynch & Age Wave (2018). Women and Financial Wellness: Beyond the Bottom Line.
GL03 Mostofsky, E. et al. (2012). Risk of acute myocardial infarction after the death of a significant person in one’s life. Circulation. (1,985 patients.)
GL04 See Womanship research.
GL05 Doka, K.J. (Ed.) (1989). Disenfranchised Grief: Recognizing Hidden Sorrow. Lexington Books.
GL06 Sue Ryder (2019). #JustSaySomething survey of 1,061 bereaved UK adults.

The World Around Us

WA01 VTI, Swedish National Road and Transport Research Institute (2023). SET 50F average female crash test dummy; Forman, J. et al. (2019). Traffic Injury Prevention.
WA02 Netherlands, Lex Van Oven, in force 1 January 1957.
WA03 Tweede Kamer der Staten-Generaal (Dutch House of Representatives): women eligible from 1917, voting from 1919.
WA04 Women’s History Archives, Iceland (Kvennasögusafn Íslands).
WA05 World Bank (2026). Women, Business and the Law 2026.
WA06 Health and Care Act 2022 (United Kingdom).
WA07 International Labour Organization (2024). Data on unpaid care responsibilities and labour force participation.
WA08 Kingma, B. & van Marken Lichtenbelt, W. (2015). Energy consumption in buildings and female thermal demand. Nature Climate Change.
WA09 UNODC & UN Women (2025). Femicides in 2024: Global estimates of intimate partner/family member femicides.
WA10 UN Women (2025). Women in political leadership data.
WA11 Girlguiding (2025). Girls’ Attitudes Survey 2025.
WA12 See Womanship research.
WA13 UNODC (2024). Global Report on Trafficking in Persons 2024.
WA14 Herman, J.L. & Flores, A.R. (2025). How many adults and youth identify as transgender in the United States? Williams Institute, UCLA School of Law.

Womanship research

Womanship (2021–25). Ongoing research with women: three survey waves, 2021–2025, 500+ in 28 countries. Unpublished data.
Cards: CF09, SR09, MF10, EW03, EW10, EW12, PW10, MA10, GL04, WA12, GF01–GF05.