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Leonard Sax vs. transgender people

Leonard Sax is an American psychologist, family physician, author, sex segregationist, and anti-transgender activist.

Sax is author of the 2005 book Why Gender Matters: What Parents and Teachers Need to Know about the Emerging Science of Sex Differences, which released a second edition in 2017. Sax is a prominent promoter of sex segregation is schools. Sax has also used an extremely narrow definition of differences of sex development to claim “the true prevalence of intersex is seen to be about 0.018%.”

Sax also believes the increase in autism diagnoses is “the medicalization of misbehavior” by “the pharmaceutical/counseling complex.” Sax notes that exposure to endocrine disruptors like polyethylene terephthalate (PET) may play a role, but Sax believes the key reasons are poor parenting, schools receiving more money for diagnosed students, and parents using autism as an excuse to avoid responsibility for their child’s behavior.

Sax frequently appears on anti-trans media, including Daily Wire, Fox News, PragerU, Steven Crowder, Allie Beth Stuckey, and Megyn Kelly. Sax has written for First Things, New York Post, Public Discourse, Identity Project, and Institute for Family Studies.

Background

Leonard David Sax was born in March 1960 to pediatrician Janet Berman Sax (1924–2008) and accountant Hilary H. “Harry” Sax. Sax has two siblings. In around 1960, Janet Sax moved from Texas to Ohio with the three children.

Leonard Sax grew up in Shaker Heights, Ohio and attended public schools there. Sax earned a bachelor’s degree from Massachusetts Institute of Technology in 1980. Sax then attended University of Pennsylvania, earning a medical degree and a doctorate in 1986. Following a three-year residency in family medicine in Lancaster, Pennsylvania, Sax launched Poolesville Family Practice, a primary care medical practice in Montgomery County, Maryland in 1990. Sax took a sabbatical from medicine from 2008 to 2013, at which time Sax was employed by Lancaster General Health.

In 2002, Sax co-founded the National Association for Single-Sex Public Education (NAASPE/NASSPE) with spouse Katie Kautz and Janet Phillips. The organization changed its name in 2011 to National Association for Choice in Education (NACE) to include private schools. From 2003 to 2012, the organization held an anuual conference.

Sax also founded the nonprofit The Montgomery Center for Research in Child and Adolescent Development in 2003.

Sax is married to nurse Kathleen J. “Katie” Kautz. They have one child.

Anti-trans activism

In 2008, linguist Mark Liberman interviewed another linguist who placed Sax’s work and views in context:

And I share with you the impression that there’s a recent increase, on the supply side, in work on the biology of cognitive and behavioral gender differences. Partly, I think, this reflects a general swing of the epistemological pendulum from nurture to nature over the past 50 years. But there’s also something more specific: the way that a certain kind of argument has spread from one end of the political spectrum to the other.

This is a view about the nature of men and women that started among feminists who think of themselves as progressive — I first saw a version of it in works by Carol Gilligan and Deborah Tannen — and has more recently recently been adopted by social conservatives. Louann Brizendine and Leonard Sax are part of this process.

It features a sort of female triumphalism, as in the slogan on the back cover of Brizendine’s book “Men, get ready to develop brain envy”, along with negative images of males, as in Sax’s title “Boys Adrift: the five factors driving the growing epidemic of unmotivated boys and underachieving young men”.

This started out as a way to validate traditionally feminine characteristics (like gossip and empathy), and to devalue traditionally masculine characteristics (like aggression and stoicism). But it was inevitably tinged with stereotyped ideas of what men and women are like; and it often flirts with a more nuanced version of the strongly anti-male rhetoric of people like Mary Daly.

Sax published a critical response to the 2018 American Academy of Pediatrics policy statement “Ensuring Comprehensive Care and Support for Transgender and Gender-Diverse Children and Adolescents.” Sax cites conservative clinicians Madeleine S C Wallien, Peggy T Cohen-Kettenis, Kenneth Zucker, and Devendra Singh.

In a 2021 supplement written to accompany presentations on Why Gender Matters, Sax cites Lisa Selin Davis, Ray Blanchard, Anthony Bogaert, Richard Pillard, Lisa Diamond, J. Michael Bailey, and Bailey’s book The Man Who Would Be Queen.

References

Moyer, Melinda Wenner (January 22, 2016). There Has Been No Collapse of Parenting. Slate https://slate.com/human-interest/2016/01/leonard-sax-is-wrong-authoritarian-parenting-can-be-bad-for-kids.html

Cable, Kelly E.; Spradlin, Terry E. (Fall 2008). Single-Sex Education in the 21st Century. Center for Evaluation & Education Policy https://files.eric.ed.gov/fulltext/ED503856.pdf

Staff report (September 2008) Janet B. Sax obituary. https://obits.cleveland.com/us/obituaries/cleveland/name/janet-sax-obituary?id=27100513

Liberman, Mark (August 19, 2008). Interview: The new fashion for biological determinism. Language Log http://languagelog.ldc.upenn.edu/nll/?p=467

Coverage in anti-trans press

Staff report (2025). Introducing the 2025 TIME100 Next: Leonard Sax. Time https://time.com/author/leonard-sax/

Walsh, Matt (August 2, 2024). Wokeness Turns The Olympics Into A Farce. Daily Wire https://www.dailywire.com/news/wokeness-turns-the-olympics-into-a-farce

Sapir, Leor (Winter 2022). Transgender Confusions: A series of court rulings illustrates how bad ideas travel from fringe academic theory into law and policy. City Journal https://www.city-journal.org/article/transgender-confusions

Bauerlein, Mark (April 30, 2010). Leonard Sax and the Girl Problem. Chronicle of Higher Education http://chronicle.com/blogPost/Leonard-Saxthe-Girl/23632 [archive]

Brooks, David (June 11, 2006). The Gender Gap at School. New York Times https://www.nytimes.com/2006/06/11/opinion/11brooks.html

Ripley, Amanda (February 27, 2005). Who Says A Woman Can’t Be Einstein? Time https://time.com/archive/6596574/who-says-a-woman-cant-be-einstein/ original url https://time.com/time/magazine/article/0,9171,1032301-3,00.html Cover story title: The Math Myth: The real truth about women’s brains and the gender gap in science.

Selected anti-trans writing by Sax

Sax, Leonard (April 9, 2025). Parents Versus Public Schools: Supreme Court to Consider Transgender Instruction. Institute for Family Studies https://ifstudies.org/blog/parents-versus-public-schools-supreme-court-to-consider-transgender-instruction

Families of Character with Jordan Langdon and Leonard Sax (December 29, 2024). Why Gender Matters: Dr. Leonard Sax on Gender Identity Confusion in Kids. https://www.familiesofcharacter.com/blogs/podcast/why-gender-matters-dr-leonard-sax-on-gender-identity-confusion-in-kids

Sax, Leonard (May 24, 2024). New Research Finds Huge Differences Between Male and Female Brains: A new study shows huge differences, with no overlap between women and men. Psychology Today https://www.psychologytoday.com/us/blog/sax-on-sex/202405/ai-finds-astonishing-malefemale-differences-in-human-brain

Sax, Leonard (July 24, 2024). New Brain Research Confirms That Gender Differences Are Hardwired. Institute for Family Studies https://ifstudies.org/blog/new-brain-research-confirms-that-gender-differences-are-hardwired

Sax, Leonard (February 5, 2024). Intersexual Politics. Salvo https://salvomag.com/article/salvo69/intersexual-politics

Sax. Leonard (November 17, 2021). Why Gender Matters [lecture supplement]. https://www.leonardsax.com/trinity6.pdf

CMDA Matters. with Mike Chupp, Jeff Barrows, and Leonard Sax (November 12, 2020). Dr. Leonard Sax: Why Gender Matters – Part 1. https://cmda.org/podcast/dr-leonard-sax-why-gender-matters-part-1/

Sax, Leonard (March 27, 2019). A New Study Blows Up Old Ideas About Girls and Boys Is gender a mere tool of the patriarchy? Or is it hardwired prior to birth? Psychology Today https://www.psychologytoday.com/us/blog/sax-sex/201903/new-study-blows-old-ideas-about-girls-and-boys

Sax, Leonard (March 13, 2019). Politicizing Pediatrics: How the AAP’s Transgender Guidelines Undermine Trust in Medical Authority. Public Discourse https://www.thepublicdiscourse.com/2019/03/50118/

Sax Leonard (January 15, 2019). Psychology as Indoctrination: Girls Rule, Boys Drool? Institute for Family Studies https://ifstudies.org/blog/psychology-as-indoctrination-girls-rule-boys-drool

Sax, Leonard (October 23, 2018). RE: Ensuring Comprehensive Care and Support for Transgender and Gender-Diverse Children and Adolescents. https://publications.aap.org/pediatrics/article/142/4/e20182162/37381/Ensuring-Comprehensive-Care-and-Support-for

Sax, Leonard (May 29, 2018). Of Boys and Toys. Institute for Family Studies https://ifstudies.org/blog/of-boys-and-toys

Sax, Leonard (December 17, 2015). Parenting in the Age of Awfulness. Wall Street Journal https://www.wsj.com/articles/parenting-in-the-age-of-awfulness-1450397051

Sax, Leonard (June 25, 2012). Girls’ Knees and Gender Confusion: Does “equal” mean “the same”? Psychology Today https://www.psychologytoday.com/us/blog/sax-sex/201206/girls-knees-and-gender-confusion

Sax, Leonard (September 26, 2011). Are Single-Sex Schools Actually DANGEROUS? SCIENCE published an article which isn’t science – how come? Psychology Today https://www.psychologytoday.com/us/blog/sax-sex/201109/are-single-sex-schools-actually-dangerous

Sax, Leonard (December 11, 2010). Unexpected sex differences in brain development. Psychology Today https://www.psychologytoday.com/us/blog/sax-on-sex/201012/unexpected-sex-differences-in-brain-development

Sax, L. (2002). How common is lntersex? A response to Anne Fausto‐Sterling. The Journal of Sex Research, 39(3), 174–178. https://doi.org/10.1080/00224490209552139

Sax, L. (2002). Maybe men and women are different. American Psychologist, 57(6–7), 444–444. https://doi.org/10.1037/0003-066x.57.6-7.444a

Books

  • The Collapse of Parenting: How We Hurt Our Kids When We Treat Them Like Grown Ups (2015)
  • Girls on the Edge: Why So Many Girls Are Anxious, Wired, and Obsessed-And What Parents Can Do (2010)
  • Boys Adrift: The Five Factors Driving the Growing Epidemic of Unmotivated Boys and Underachieving Young Men (2007)
  • Why Gender Matters: What Parents and Teachers Need to Know about the Emerging Science of Sex Differences (2005) Doubleday, ISBN 978-0385510738
    • Why Gender Matters [second edition] (2017). Harmony, ISBN 978-0451497772

Media

PragerU with Melissa Streit and Leonard Sax (August 20, 2025). Dr. Leonard Sax on Why America’s Kids are Depressed, Anxious, & Overmedicated | Real Talk | PragerU. https://www.youtube.com/watch?v=MBdRmxGS318

Fox and Friends with Ainsley Earhardt and Leonard Sax (August 12, 2025). Liberal state’s new law called out as ‘really dangerous’. https://www.youtube.com/watch?v=fDxLvhRb5PY

Relatable with Allie Beth Stuckey and Leonard Sax (January 15, 2025). Boys Are Suddenly Failing Kindergarten. This Doctor Explains Why | Guest: Dr. Leonard Sax | Ep 1123. https://www.youtube.com/watch?v=vkRJVn3q6tU

The Megyn Kelly Show with Megyn Kelly with Leonard Sax (December 11, 2024). Why CEO Killer Snapped, Dangers of “Gentle” Parenting, & Rise of “Normophobia,” w/ Dr. Sax & DeLong. https://www.youtube.com/watch?v=x3LNe1JE_ck

Daily Wire / Andrew Klavan with Leonard Sax (November 27, 2024). The Biggest Mistakes Parents Make Today | Leonard Sax. https://www.youtube.com/watch?v=S6BFgkdIcy0

The Ross Kaminsky Show.with Ross Kaminsky and Leonard Sax (April 30, 2024). Psychologist Dr Leonard Sax on the Backlash against the Pro-Transgender Movement. https://www.iheart.com/content/2024-04-30-psychologist-dr-leonard-sax-on-backlash-against-pro-transgender-movement/

The Lila Rose Show with Lila Rose and Leonard Sax (November 24, 2023). Are Plastics, Schoolrooms and Video Games Destroying Boys? | The Lila Rose Podcast E73. https://www.youtube.com/watch?v=FuJInR0TUuM

Louder With Crowder with Steven Crowder and Leonard Sax (July 5, 2018). Transgenderism is Ideology NOT Science! (Dr. Leonard Sax Uncut) | Louder With Crowder. https://www.youtube.com/watch?v=VMb2xafRMxU

The Megyn Kelly Show with Megyn Kelly and Leonard Sax (January 18, 2023). Truth About Gender Differences, Danger of “Affirm Only” Care, and Parenting Now, w/ Dr. Leonard Sax. https://www.youtube.com/watch?v=gmTX2T44UDs

Me Time With Frangela with Frances Callier, Angela Shelton, and Leonard Sax (October 3, 2018). S1E18: Boys vs Girls. [unavailable online]

CBS Mornings with Norah O’Donnell, Jeff Glor, and Leonard Sax (December 28, 2015). Family doctor says children given too much power. https://www.youtube.com/watch?v=Rjr6LCbn_wQ

skyeba / TODAY Show with Al Roker and Leonard Sax (November 15, 2007). Al Roker interviews Leonard Sax, “Why Gender Matters.” https://www.youtube.com/watch?v=eXqiJLZm-DI

Resources

Leonard Sax (leonardsax.com)

Why Gender Matters (whygendermatters.com) [archive]

National Association for Single-Sex Public Education (singlesexschools.org) [archive]

National Association for Choice in Education (4schoolchoice.org)

The Montgomery Center for Research in Child and Adolescent Development (mcrcad.org)

Wikipedia (en.wikipedia.org)

Psychology Today (psychologytoday.com)

X/Twitter (x.com)

Facebook (facebook.com)

Vimeo (vimeo.com)

IMDb (imdb.com)

Institute for Family Studies (ifstudies.org)

The Witherspoon Institute / Public Discourse (thepublicdiscourse.com)

  • Leonard Sax
  • thepublicdiscourse.com/author/leonard-sax

Identity Project (identityproject.tv)

Muck Rack (muckrack.com)

New York Post (nypost.com)

First Things (firstthings.com)

  • Leonard Sax
  • firstthings.com/archive/?_author=leonard-sax