Amicus Curiae Brief — Bradley Little, Governor of Idaho, et al., Petitioners v. Lindsay Hecox, et al.

Nos. 24-38 & 24-43 vide 24-44

IN THE

Supreme Court of the United States

————

BRADLEY LITTLE, GOVERNOR OF IDAHO, et al.,

Petitioners,

v.

LINDSAY HECOX, et al.,

Respondents.

————

WEST VIRGINIA, et al.,

Petitioners,

v.

B.P.J. BY HER NEXT FRIEND AND MOTHER,

HEATHER JACKSON,

Respondent.

————

On Petitions for Writs of Certiorari to the

United States Courts of Appeals

for the Ninth and Fourth Circuit

————

BRIEF OF AMICUS CURIAE

INDEPENDENT COUNCIL ON WOMEN’S

SPORT IN SUPPORT OF PETITIONERS

————

WILLIAM BOCK III

Counsel of Record

KROGER GARDIS AND REGAS, LLP

111 Monument Circle, Suite 900

Indianapolis, Indiana 46204

(317) 777-7412

wbock@kgrlaw.com

Counsel for Amicus Curiae

August 14, 2024

WILSON-EPES PRINTING CO., INC. – (202) 789-0096 – WASHINGTON, D.C. 20002

i

TABLE OF CONTENTS

TABLE OF CONTENTS .............................................. i

TABLE OF AUTHORITIES ....................................... iii

INTEREST OF AMICUS CURIAE ............................. 1

SUMMARY OF ARGUMENT ..................................... 1

ARGUMENT ................................................................ 2

I.

II.

Experience of Individual Amici ........................ 2

A.

Lauren Bondly, Age-Group National

Champion Triathlete, U.S. National

Team Member, Engineer ....................... 2

B.

Jennifer Sey, U.S. National Champion

Gymnast, U.S. National Team Member

First Female Global Brand President at

Levi Strauss & Co., Producer of Emmy

Award Winning Documentary on Abuse

of U.S. Gymnasts.................................... 5

C.

Janel Jorgensen McArdle, Olympic

Silver Medalist, Chief Operating Officer

Swim Across America ............................ 8

D.

Marshi Smith, NCAA Champion,

Medical Device Sales Representative,

ICONS Co-Founder .............................. 12

Sex is a Biological Fact and Athletic

Performance is Tied Directly to Sex............... 14

A.

Biological Sex is the Dominant Factor

Influencing Sport Performance ........... 14

B.

Male Sport Performance Advantage is

Clearly Apparent at Every Age, Even

Pre-Puberty .......................................... 17

1.

Higher Androgen Levels in Male

Infants........................................ 18

ii

2.

III.

Differences in Pre-Pubertal

Skeletal Size and Strength ....... 21

3.

Male-Female Differences Elude

Complete Description in any

Space Limited Survey ............... 21

C.

Male Advantage Exists Even After

Attempts to Suppress Testosterone

Levels .................................................... 22

Sex Separation is Essential to Preserving

Female Opportunities in Sport ...................... 23

A.

A Category for Female Athletes Based

on Sex is How Women Participate in

Sport Equally to Men ........................... 23

B.

Without Protection of the Girl’s

Category Girls Will Drop Out of

Competitive Sport ................................ 25

C.

Requiring Sport to Accept Eligibility

Rules Not Based on Objective Criteria

Harms Both Women and Sport ........... 26

CONCLUSION .......................................................... 27

iii

TABLE OF AUTHORITIES

Cases

A.M. by E.M. v. Indianapolis Pub. Sch.,

617 F.Supp.3d 950 (S.D. Ind. 2022) ............ 18-20, 22

Statutes

Title IX of the 1972 Education Amendments, Pub. L.

92-318, Title IX, 20 U.S.C. § 1681 et seq

................................................................. 2, 6-7, 23-25

Rules

Sup. Ct. R. 37 ............................................................... 1

Sup. Ct. R. 37.2(a)........................................................ 1

Sup. Ct. R. 37.6 ............................................................ 1

Other Authorities

Becker et al., 2015. Hormonal ‘minipuberty’

influences the somatic development of boys but not

of girls up to the age of 6 years. Clinical

Endocrinology 83: 694-701 .................................... 20

Bidlingmaier, F., Dorr, H.G., Eisenmenger, W.,

Kuhnle, U., Knorr, D., “Contribution of the adrenal

gland to the production of androstenedione and

testosterone during the first two years of life,” J

Clin Endocrinol Metab. 1986 62:331–335 ............. 19

Boogers et al., 2022. Trans girls grow tall: adult

height is unaffected by GnRH analogue and

estradiol treatment. Journal of Clinical

Endocrinology and Metabolism ............................. 23

British Journal of Sports Medicine 55(15): 865-872 23

iv

Catley MJ, Tomkinson GR. Normative health-related

fitness values for children: analysis of 85347 test

results on 9-17-year-old Australians since 1985. Br

J Sports Med. 2013 Jan;47(2):98-108 .................... 17

Gilsanz, V., Kovanlikaya, A., Costin, G., Roe, T.F.,

Sayre, J., Kaufman F., “Differential Effect of

Gender on the Sizes of the Bones in the Axial and

Appendicular Skeletons,” Journ. of Clinical

Endocrin. & Metabolism, Volume 82, Issue 5, 1

May 1997, Pa .......................................................... 21

Handelsman, D.J., Hirschberg, A.L., Bermon, S.,

“Circulating Testosterone as the Hormonal Basis of

Sex Differences in Athletic Performance,” Endocr.

Rev. 2018 Oct; 39(5): 803-829 .......................... 15, 26

Hilton, E.N., Lundberg, T.R., “Transgender Women

in the Female Category of Sport: Perspectives on

Testosterone Suppression and Performance

Advantage,” Sports Medicine (2021) 51:199-214,

p. 199 (hereafter “Hilton & Lundberg, Female

Category of Sport”) ................................................. 15

Kiviranta et al., 2016. Transient Postnatal Gonadal

Activation and Growth Velocity in Infancy.

Pediatrics 138(1): e20153561 ................................. 20

Lanciotti L, Cofini M, Leonardi A, Penta L, Esposito

S. Up-To-Date Review About Minipuberty and

Overview on Hypothalamic-Pituitary-Gonadal Axis

Activation in Fetal and Neonatal Life. Front

Endocrinol (Lausanne). 2018 Jul 23;9:410 ............ 20

Pang, S., Levine, L.S., Chow, D., Sagiani, F., Saenger,

P., New, M.I., “Dihydrostestosterone and its

relationship to testosterone in infancy and

childhood,” J Clin Endocrinol Metab. 1979 48:821–

826........................................................................... 20

v

Pedersen, 1980. Ultrasound evidence of sexual

difference in fetal size in first trimester. British

Medical Journal 281(6250): 1253 .......................... 19

Schwartzler et al., 2004. Sex-specific antenatal

reference growth charts for uncomplicated

singleton pregnancies at 15–40 weeks of gestation.

Ultrasound in Obstetrics and Gynaecology 23(1):

23-29 ....................................................................... 19

Tambalis KD, Panagiotakos DB, Psarra G,

Daskalakis S, Kavouras SA, Geladas N,

Tokmakidis S, Sidossis LS. Physical fitness

normative values for 6-18-year-old Greek boys and

girls, using the empirical distribution and the

lambda, mu, and sigma statistical ........................ 18

1

INTEREST OF AMICUS CURIAE 1

Amici are the Independent Council on Women’s

Sport (ICONS) and its members identified in Section I

below. ICONS is a network and advocacy group

comprised of current and former collegiate and

professional women athletes, their families and

supporters who believe the next generation of women

and girls deserve the chance to be champions and to

see an expanded and celebrated world of women’s

sports. Reflecting their experience, amici have an

interest in the preservation of the female category in

sport.

SUMMARY OF ARGUMENT

Recognizing biological differences between the

sexes and protecting women’s spaces from male

intrusion are foundational for women to succeed in

sports and in life. It is the experience of amici that

legal protections giving women the opportunity to take

part in and succeed in sport are essential to the

advancement of women and depend on the law’s basic

ability to distinguish between women and men and

courts’ capacity to evaluate, compare, and equalize the

opportunities of the former in comparison to those of

the latter.

1 Rule 37 statement: The parties were notified of the filing of this

brief more than 10 days before its filing. See Sup. Ct. R. 37.2(a).

No party’s counsel authored any of this brief; amici alone funded

its preparation and submission. See Sup. Ct. R. 37.6.

2

In contrast, equating “gender identity” to “sex”

in Title IX of the 1972 Education Amendments, Pub.

L. 92-318, Title IX, 20 U.S.C. § 1681 et seq. (“Title IX”)

and the Equal Protection Clause to the U.S.

Constitution will diminish irreplaceable and life

changing opportunities and degrade legal protections

for women and girls. To prevent these harms this

Court should grant the Petitions for Writs of

Certiorari in Little v. Hecox, No. 24-38 and in West

Virginia v. B.P.J., No. 24-43 Vide 24-44 and reverse

the decisions of the Fourth and Ninth Circuits.

ARGUMENT

I.

Experience of Individual Amici

Sex separated sport is necessary for girls to

develop a healthy view of their own bodies. For many

girls, lessons learned in sport are vital to overcoming

obstacles and succeeding in life. Yet, due to male

biological advantages, failing to protect the girls’

category will cause girls to leave sport. Therefore,

protecting sex separation in girls’ sports is

foundational to the health, happiness, and success of

future generations of women.

A.

Lauren Bondly, Age-Group National

Champion Triathlete, U.S. National

Team Member, Engineer

Lauren Bondly explains why participation in

sex separated sport is vital to women developing a

healthy view of their own bodies:

3

“It is impossible for me to overstate the

importance competitive sport has played in my life. I

can say without risk of hyperbole it saved my life and

career.

“Like many young women, I suffered from

anorexia in my late teens and early twenties. I began

running to burn calories and create another means to

control my compulsive weight loss. One day I entered

a local 5k road race and in part because I had given

myself permission to eat a full meal the night before –

just for this special occasion – I ended up winning my

age group. This was the turning point in my illness.

“Anorexia deceives sufferers into believing it is

virtuous to be hungry, that each lower number on the

scale is an accomplishment – no matter how low it

goes. But at that race, I had achieved a real

accomplishment more powerful than the fake selfesteem boosts anorexia offered. I looked at the

women’s podium, at strong, incredible female bodies

and realized they were not all that different from

mine. All I had to do was get healthy, redirect my

obsessive tendencies and one day that could be me on

the overall women’s podium. Now on occasion – it is.

Through sport, I re-learned my relationship with food

and my body; I don't know if I would have otherwise.

“Fast forward to graduation from college with a

degree in engineering, I soon learned why my chosen

career has the reputation it does. Years at my first

company were full of unwanted sexual advances and

some of the most inappropriate comments imaginable

until I left for a company where I was initially treated

4

like a secretary instead of an engineer. In the middle

of that period, I switched to triathlon needing

something more challenging to convince myself of my

capability in the face of so many claiming I was

incapable. If I did not have that one outlet where I

could count on having a fair chance to succeed, I would

have thrown my diploma in the trash and quit

engineering. Today I am happy and satisfied with my

career, but it would have been unbearable to continue

facing unfairness and humiliation day after day in

those earlier years if I had not had competitive sport

to balance it out.

“Sport is not just a game. I have witnessed the

desire to be the best motivate women to quit alcohol

and drugs, to leave abusive relationships, and like me,

to overcome mental health issues and foster the

fortitude to endure and overcome injustice.

Sport is too important to turn it into a tool that

teaches girls to get comfortable being on the receiving

end of injustice, or that hard work and overcoming

adversity is futile. We cannot replace the strong

female bodies on the women’s podium with impossibly

unattainable male bodies and pretend that will have

no effect on young girls and women who need strong

female role models.

Finally, sport must be about fairness. If women

do not deserve and receive fairness in the one place

where ‘fair play’ is supposed to be ensured and upheld,

what chance do women have in business or elsewhere

where women are treated unfairly, and are told to, and

expected to, just accept it?”

5

B.

Jennifer

Sey,

U.S.

National

Champion Gymnast, U.S. National

Team Member First Female Global

Brand President at Levi Strauss &

Co., Producer of Emmy Award

Winning Documentary on Abuse of

U.S. Gymnasts

Sport is integral to girls overcoming obstacles

and succeeding in life. From age 6 Jennifer Sey

pursued her dream of competing on the U.S.

gymnastics team and winning a national

championship, a goal she realized after more than 10

years of dedication and hard work.

The determination developed as an athlete

fueled a pioneering career in business and led her to

stand up for the rights of marginalized individuals.

Jennifer began working as an entry level employee at

Levi Strauss & Co. in 1999, eventually becoming chief

marketing officer and then the first female brand

president, never losing focus on a desire to use her

opportunities as a platform to help others.

Jennifer experienced abusive training practices

as an elite gymnast which she wrote about in her 2009

autobiography, Chalked Up, a book other gymnasts

would point to as giving them courage to speak up. In

2017 Jennifer became an executive co-sponsor of the

first black employees’ group at Levi’s, engaging the

company in improving racial diversity. She was a

producer of Athlete A, a documentary on the Larry

Nassar scandal at USA Gymnastics which won an

6

Emmy as the

Documentary. 2

2020

Outstanding

Investigative

In 2021 Jennifer told NBC commentator and

Know Your Value founder Mika Brzezinski, “I suffered

from imposter syndrome probably up until about last

year. . . I went to Stanford coming out of gymnastics. I

was convinced that at any moment, somebody was

going to pop out from behind the curtain and tell me I

didn’t belong. A lot of women . . . have this.” 3 Jennifer

explained her experiences in competitive gymnastics

helped find her voice and shape her leadership style,

telling Brzezinski, “I’ve learned that your life and

journey is not a straight line, and you will get knocked

down. When you advocate for yourself, it’s not always

going to go the way that you want. But you keep

going.” 4

Jennifer’s path to career success flowed directly

from lessons learned as a female athlete, and she is

concerned that allowing males to compete in the

female category of sport will deprive girls of

opportunities to compete on a level playing field. She

explains:

“I started gymnastics in 1975, at 6 years old,

just three years after the passage of Title IX. In 1976

2 See

https://www.indystar.com/story/news/local/2021/10/01/athlete-awins-emmy-outstanding-investigativedocumentary/5945215001/.

3 See https://www.nbcnews.com/know-your-value/feature/how-iwent-elite-gymnast-global-brand-president-levi-s-ncna1272382/.

4 Id.

7

Nadia Comaneci won the Olympics. Accelerated by

the passage of Title IX, gyms started popping up all

over the United States – and active little girls like me

took to them in droves. With the promise of college

scholarships, sport – and gymnastics in particular –

gave little girls a chance to thrive.

“By age 10 I made my first National Team. And

in 1986, just 9 months after fracturing my femur at

the World Championships, I became the National

Champion. Gymnastics taught me the values of

perseverance, hard work, and discipline. Ultimately, I

learned that never giving up meant I could achieve

mastery; I learned applying my passion for sport could

make me a champion; and I learned directing my

commitment could result in a hard-won sense of

personal fulfillment.

“After leaving competitive sport, I applied these

lessons to my career in business. I started at Levi’s in

1999 as an entry level assistant. Corporate America

was then rife with sexism and sexual harassment. I

put my head down and worked hard. I was highly

coachable, and I never gave up, always wanting to get

better at my craft. Ultimately, in 2020 I became Levi’s

first female Global Brand President after years as an

award-winning Chief Marketing Officer.

“My time as an elite athlete was invaluable,

honing the perseverance required to succeed in

business. Knowing I could compete on an even playing

field against other fiercely dedicated girls and succeed

amidst injuries, losses, and other setbacks, shaped me,

and enabled my success as a woman in business.

8

“Recent developments in U.S. sport cause me

concern. I see the opportunities of fiercely dedicated

girls and young women to compete on a level playing

field being sacrificed to a view that says the

opportunities of women must take second place to the

feelings of males seeking validation through playing

women’s sport. The idea that the rights of girls must

be sacrificed to make others feel better about

themselves must be fought vigorously. If it is not, it

will lead directly to the feelings of inadequacy and

helplessness that plague young girls and against

which I have been fighting all my life.”

C.

Janel Jorgensen McArdle, Olympic

Silver Medalist, Chief Operating

Officer Swim Across America

Janel Jorgensen McArdle knows that protecting

sex separated sport is essential to girls remaining in

sport. She speaks from the experiences of a life at the

highest levels of competitive sport and sport-based

philanthropy and as a woman heading a national

organization with thousands of volunteers that has

raised over $100 million for cancer research,

prevention, and treatment.

Janel first faced unfair competition when she

reached the pinnacle of her sport, competing against

the East Germans at the Seoul Olympics in 1988. She

explains, “We all knew what was happening and we

knew we were robbed of a gold medal we deserved. We

were told to be silent, to not risk being called poor

losers. Now, decades later, it’s well understood the

9

East Germans were doping, and East German victory

was tainted.

“Testosterone and androgenizing drugs were

given in large quantities to East German athletes,

creating an unfair advantage clean athletes could not

overcome. The East German scandal was enormous

and remains a black mark on the history of women’s

sport. Yet, the scandal we are creating in women’s

sports today is even worse. I had the benefit of sextesting, a cheek swab to verify my biology. I knew with

full confidence the athletes I was racing were women,

even if some were artificially enhanced with male

androgens.

“However, despite every possible effort to

enhance their performance with drugs, East German

women could not have qualified to compete with the

men. But now, by allowing male bodies in women’s

sport we are taking unfairness to another level, not

even hiding the intent to make women face an

insurmountable physical obstacle, barely debating

how much unfairness women in sport will face.

“Today, we do not ask women to compete

against women who have taken drugs, we ask women

to compete against the biological advantage of being

born male that even women on drugs could not

overcome. There is no excuse for asking female

athletes, of any age, to compete with less talented

versions of male biology.

“I left the Olympics with a silver medal at 17

and continued my swimming career, winning 17

10

National Championships at Stanford, wrapping up a

career that gave me amazing opportunities,

friendships, and skills. Then, I went to work in the

corporate world, and 13 years later, with my father

facing cancer, an opportunity came to lead Swim

Across America, a non-profit dedicated to raising

money and awareness for cancer research, treatment,

and prevention.

“Working at Swim Across America has been a

way that a sport so impactful and important in

shaping my life has helped me benefit the lives of

others. I have been involved with Swim Across

America for over 35 years in many roles: Olympian,

swimmer, board member, COO, and CEO, and

repeatedly seen how my sport of swimming has

changed, and in some cases saved, people’s lives.

“Yet, for as much as I love swimming, I know

that if I had been faced with gross unfairness in my

sport early on or repeatedly, I would not have

continued. If I stood on the block next to a male body

that I knew I could not beat, the frustration would

have forced me to quit. Had that happened my life may

have had fewer meaningful and significant

opportunities to impact others.

“I want sport for girls growing up today to be

what it was for me until I got to the Olympics . . . an

amazing environment where I learned confidence,

perseverance, and grit. I know what it feels like to step

up to the starting block and know that even if I were

given a head start, I couldn’t compete against the

illegal drugs pulsing through my competitor’s veins. I

11

know what it feels like to be a 17-year-old girl standing

on the Olympic podium holding the wrong-colored

medal because it wasn’t a fair race. I don’t want other

young girls and women to endure similar experiences,

but I see that they are, and with increasing regularity.

There is no excuse for perpetuating this injustice. Our

girls deserve fair and equal opportunities in sports.

“After all the progress women have made in

recent decades, I do not understand why so many

people are turning a blind eye to injustice and to the

history of what women have fought for. Of course, boys

and men facing gender dysphoria should be cared for,

however, allowing them to compete in the women’s

category only unjustly shifts pain and unfairness to

girls and women who will throughout their lives in

sport face a deficit far greater than I faced in the

starting blocks in Seoul when lining up against the

East Germans.

“Some say sport only needs to be fair at the

highest, most elite levels. I emphatically disagree.

Girls need to know they don’t have to reach elite levels

to be worthy of fair treatment and fair competition. If

rules and laws do not clearly convey that girls deserve

fair sports at every level, many will forsake athletic

opportunities. But we also risk something even worse,

adults communicating to girls that fairness is not

really a concept that applies to them.”

12

D.

Marshi Smith, NCAA Champion,

Medical

Device

Sales

Representative, ICONS Co-Founder

Marshi Smith explains why protecting girls’

sport is essential to future generations of women – “I

started my career in sales shortly after graduating

from the University of Arizona. My Olympic dreams

had been torn away from me by a training-induced,

shoulder injury the year after winning a NCAA

backstroke title. Heartbroken, I found myself

suddenly sitting across a desk from managers asking

me to convince them to hire me with exactly zero hours

of work experience on my resume. I stepped into the

interview underqualified on my resume but extremely

confident in my own ability to learn and thrive. When

the management team asked me about my work

experience, I told them the story of my junior year on

the swim team.

“At the start of that season, I told myself and

my coach I had decided to win an NCAA title. I wrote

a goal sheet outlining the race to achieve my goal time,

52.82 a time I chose to break my school record by .01

seconds. I described my devotion to reaching that goal

from swimming sets before dawn to running hundreds

of grueling stadium steps and always drifting to sleep

believing

my

dream

was

achievable…52.82…52.82…52.82. I talked about

walking onto the pool deck at the NCAA

Championships that year knowing nobody could

possibly want to win more than I did. And then I did.

I touched the wall in 52.82 exactly to the hundredth of

a second. I broke my school record. I won a national

13

title. The manager hired me on the spot.

“At the time I was one of only two women

working for the company in a national sales position.

I stood on the national stage as a top sales

representative several times in my career, often as one

of very few women. They say, ‘a picture is worth a

thousand words.’ Below is a picture of the 2017

National Sales Meeting ‘Territory of the Year’ Award

winners from my company. It won’t be difficult for the

reader to pick me out in the picture. Yet, I know my

life would not have led to that stage had men been

allowed to compete against me in sport.

“Although my goal has changed, I have equal

passion and devotion today to what I had on my college

pool deck. My new goal sheet commits to preserving

the equal chance for my seven-year-old daughter to see

herself as a champion. She has just begun her swim

lessons and deserves the same opportunity to

participate and win in her sport that my son does. I

cannot sit by and accept that I may have been one of

the last generations of women with the right to fair

treatment and equal opportunity in sport. This

generation and the next deserve to tell the stories that

launch careers.

The women’s category in sport has tremendous

value for women. Separating girls from boys is the

indispensable key to unlocking the transformative

power of sport to change young girls’ lives. If legal

decisions throw away that key, it will place the dreams

of millions of young girls outside their reach and

communicate that young girls, unlike boys, are not

14

deserving full protection even from a law that was

meant to protect them.”

II.

Sex is a Biological Fact and Athletic

Performance is Tied Directly to Sex

A.

Biological Sex is the Dominant

Factor

Influencing

Sport

Performance

A recent peer reviewed study reports that post

puberty “the performance gap between males and

females . . . often amounts to 10–50% depending on

sport.” 5 “Sex is a major factor influencing best

Hilton, E.N., Lundberg, T.R., “Transgender Women in the

Female Category of Sport: Perspectives on Testosterone

Suppression and Performance Advantage,” Sports Medicine

(2021) 51:199-214, p. 199 (hereafter “Hilton & Lundberg, Female

Category of Sport”).

5

15

performances and world records” 6 in Olympic sport. In

a study of performance by some of the most highly

trained athletes in the world, researchers evaluated

82 quantifiable events since the beginning of the

Olympic era (i.e., from 1896 to 2007). They found men

outperformed women in all sports with a mean

difference of 10.0% ± 2.94% between them depending

upon event. 7

“There is a clear sex difference in both muscle

mass and strength even adjusting for sex differences

in height and weight. On average women have 50% to

60% of men’s upper arm muscle cross-sectional area

and 65% to 75% of men’s thigh muscle cross-sectional

area, and women have 50% to 60% of men’s upper limb

strength and 60% to 80% of men’s leg strength. Young

men have on average a skeletal muscle mass of >12 kg

greater than age-matched women at any given body

weight.” 8 The impact is “an obvious performance

enhancing effect[.]” 9

6 Thibault, V., Guillaume, M., Berthelot, G., El Helou, N., Schaal,

K., Quinquis, L., Nassif, H., Tafflet, M., Escolano, S., Herine, O.,

Toussaint, J.F., “Women and men in sport performance: The

gender gap has not evolved since 1983,” Journal of Sports Science

and Medicine (2010) 9, 214-223, p. 214, available at:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3761733/

7 Id. They also observed many of these timed performances for

women “coincided with later-published evidence of stateinstitutionalized or individual doping,” suggesting the gender gap

is actually even larger than the reported statistical differences.

Id.

8 Handelsman, D.J., Hirschberg, A.L., Bermon, S., “Circulating

Testosterone as the Hormonal Basis of Sex Differences in Athletic

Performance,” Endocr. Rev. 2018 Oct; 39(5): 803-829 (hereafter,

“Handelsman, et al., Sex Differences in Athletic Performance”).

9 Id.

16

“[O]n average men are 7% to 8% taller with

longer, denser, and stronger bones, whereas women

have shorter humerus and femur cross-sectional areas

being 65% to 75% and 85%, respectively, those of

men.” 10 The athletic advantages conferred by men’s

larger and stronger bones includes, “greater leverage

for muscular limb power exerted in jumping, throwing,

or other explosive power activities” and greater male

protection from stress fractures. 11

The sex-based performance gap is not limited to

certain sports but applies generally to most skills

necessary for success in sport. The following chart

illustrates male advantage across a wide group of

discrete sport skills.

Reproduced from: Hilton &

Category of Sport p. 202, Fig. 1.

10 Id.

11 Id.

Lundberg,

Female

17

B.

Male Sport Performance Advantage

is Clearly Apparent at Every Age,

Even Pre-Puberty

As the foregoing makes clear, the sex-based

sport performance gap is not just real, it is massive.

Furthermore, male-female performance differences

exist from the earliest stages, including in youth

sports. Study after peer-reviewed study has shown

clear performance advantages for males in sport prepuberty. 12

For instance, a comprehensive review of fitness

data from over 85,000 Australian children aged 9-17

years showed that compared to 9-year-old females,

9-year-old males were faster at short sprints (9.8%)

and one mile (16.6%), could jump 9.5% further from a

standing position (a test of explosive strength), could

complete 33% more push-ups in 30 seconds and had a

13.8% stronger grip. 13 A similarly large advantage for

males was found in a study of Greek children, in which

6-year-old males, compared to 6-year-old females,

completed 16.6% more shuttle runs in a given time and

could jump 9.7% further from a standing position. In

terms of aerobic endurance capacity, 6–7-year-old

males were shown to have higher absolute and relative

12 See, e.g., age group standards in USA swimming reflective of

male advantage at every age, distance and stroke, available at:

https://www.usaswimming.org/docs/defaultsource/timesdocuments/time-standards/2024/2021-2024national-age-group-motivational-times.pdf.

13 Catley MJ, Tomkinson GR. Normative health-related fitness

values for children: analysis of 85347 test results on 9-17-yearold Australians since 1985. Br J Sports Med. 2013 Jan;47(2):98108.

18

(to body mass) maximum oxygen uptake than 6–7year-old females. 14 Numerous similar peer reviewed

studies were cited in expert reports of Dr. Tommy

Lundberg of the Karolinska Institute in Stockholm

and of Dr. Emma Hilton of the University of

Manchester, UK, at the injunction phase in the A.M.

case. 15

1.

Higher Androgen Levels in

Male Infants

The Plaintiffs in the B.P.J. contended that due

to recent hormone suppression B.P.J. “will develop the

same changes to bone size, skeletal structure, [and]

pelvis shape . . . [among other characteristics] that are

typically experienced by . . . girls who go through a

typically female puberty.” Fourth Circuit Appellants’

Brief at 51 of 72. This is wrong as the studies cited

below make clear. In fact, to fully mitigate the

performance enhancing effects of testosterone on

B.P.J. hormone intervention would had to have

commenced at birth if not in the womb.

Differences in average body length (measured

as head-bottom length) can be detected by ultrasound

from the first trimester of pregnancy, with males

Tambalis KD, Panagiotakos DB, Psarra G, Daskalakis S,

Kavouras SA, Geladas N, Tokmakidis S, Sidossis LS. Physical

fitness normative values for 6-18-year-old Greek boys and girls,

using the empirical distribution and the lambda, mu, and sigma

statistical method. Eur J Sport Sci. 2016 Sep;16(6):736-46.

15 A.M. by E.M. v. Indianapolis Pub. Sch., Case No. 1:22-cv01075-JMS-DLP (S.D. Ind. 2022) (“A.M. case”), Dkt. Nos. 36-6,

36-7, 57-1, 57-2.

14

19

already longer than females. 16 Larger average skull

diameter in male fetuses at twenty weeks has been

reported. 17 Gestational growth charts track not just

higher male values for skull diameter but also

abdominal circumference and estimated fetal

weight. 18 The expert reports of Drs. Lundberg and

Hilton in the A.M. case detail these and other

significant differences in biological development

between males and females.

Research has established the existence of

higher levels of androgens in infant boys during the

first six months of their development. 19 For instance,

“[t]esticular testosterone concentrations were [found

to be] maximal in boys 1-3 months of age, with peak

values similar to those in pubertal or even adult

testes.” 20 At the same time, it was found that the

adrenal glands were important “as a source of

androstene-dione [another anabolic agent similar to

16 Pedersen, 1980. Ultrasound evidence of sexual difference in

fetal size in first trimester. British Medical Journal 281(6250):

1253.

17 Persson et al., 1978. Impact of fetal and maternal factors on the

normal growth of the biparietal diameter. Scandinavian

Association of Obstetricians and Gynaecologists 78: 21-27.

18 Schwartzler et al., 2004. Sex-specific antenatal reference

growth charts for uncomplicated singleton pregnancies at 15–40

weeks of gestation. Ultrasound in Obstetrics and Gynaecology

23(1): 23-29.

19 Bidlingmaier, F., Dorr, H.G., Eisenmenger, W., Kuhnle, U.,

Knorr, D., “Contribution of the adrenal gland to the production of

androstenedione and testosterone during the first two years of

life,” J Clin Endocrinol Metab. 1986 62:331–335, available at:

https://core.ac.uk/reader/12168690?utm_source=linkout

20 Id. at 331.

20

testosterone] in male infancy.” 21 “Testosterone and

dihydrotestosterone [another steroid] levels in

[umbilical] cord blood are higher in males than in

females. The presence of dihydrotestosterone suggests

that there is active fetal peripheral metabolism of

testosterone to dihydrotestosterone [during fetal

development].” 22

Increased testosterone levels during this “minipuberty” phase in males aged 1-6 months may be

correlated with a faster growth rate and an

“imprinting effect” on body mass index and body

weight. 23 This burst of testosterone is associated with

higher growth velocity for males in the first six months

of life, 24 higher weight gain, lower acquisition of body

fat and lower body mass index. 25 Such data led

Dr. Hilton to opine in the A.M. case that “transient

exposure to testosterone in mini-puberty thus seems

to underpin the well-established structural differences

between males and females in childhood.” 26

21 Id. at 334.

22 Pang, S., Levine, L.S., Chow, D., Sagiani, F., Saenger, P., New,

M.I., “Dihydrostestosterone and its relationship to testosterone

in infancy and childhood,” J Clin Endocrinol Metab. 1979 48:821–

826,

available

at:

https://academic.oup.com/jcem/articleabstract/48/5/821/2679038?redirectedFrom=fulltext&login=false

23 Lanciotti L, Cofini M, Leonardi A, Penta L, Esposito S. Up-ToDate Review About Minipuberty and Overview on HypothalamicPituitary-Gonadal Axis Activation in Fetal and Neonatal Life.

Front Endocrinol (Lausanne). 2018 Jul 23;9:410.

24 Kiviranta et al., 2016. Transient Postnatal Gonadal Activation

and Growth Velocity in Infancy. Pediatrics 138(1): e20153561.

25 Becker et al., 2015. Hormonal ‘minipuberty’ influences the

somatic development of boys but not of girls up to the age of 6

years. Clinical Endocrinology 83: 694-701.

26 A.M. case, Dkt. No. 36-6, ¶ 3.5.

21

2.

Differences in Pre-Pubertal

Skeletal Size and Strength

As noted above, there are differences in male

skeletal structure compared to females. In one study

of pre-pubertal subjects, the “cross-sectional areas of

[the lumbar spine] were significantly smaller in girls

than in boys.” 27 The difference between the

prepubertal boys and girls spine width was found to be

11%. 28 These researchers observed that because “only

prepubertal children were studied, . . . our results

cannot be attributed to gender differences in the

heights of upper skeletal segments, as sitting heights

and the heights of the lumbar vertebrae were similar

in boys and girls.” 29

3.

Male-Female

Differences

Elude Complete Description in

any Space Limited Survey

Dr. Hilton reports “analysis of sex-specific

genetic architecture in adults reveals some 6500

differences in gene expression, likely to influence

development and function outside of hormone

27 Gilsanz, V., Kovanlikaya, A., Costin, G., Roe, T.F., Sayre, J.,

Kaufman F., “Differential Effect of Gender on the Sizes of the

Bones in the Axial and Appendicular Skeletons,” Journ. of

Clinical Endocrin. & Metabolism, Volume 82, Issue 5, 1 May

Pages

1603–1607

available

at:

1997,

https://academic.oup.com/jcem/article/82/5/1603/2823501?login=f

alse

28 Id.

29 Id.

22

effects.” 30 She also observed that, “male advantage

over females is not limited to those physical and

functional differences conferred by male morphology,

shape and size. Most obviously, female athletes must

typically deal with the effects of the menstrual cycle

and the cyclical effects of hormones on training

capacity and performance. The menstrual cycle is

known to affect cardiovascular, respiratory, brain

function, response to ergogenic aids, orthopedics, and

metabolic parameters, and represents a barrier to

athletic capacity not experienced by males.” 31 In short,

male-female differences impacting sport performance

are so extensive they cannot be fully described in a

brief.

C.

Male Advantage Exists Even After

Attempts to Suppress Testosterone

Levels

To test the idea that testosterone suppression

and feminizing hormones would eliminate male

advantages in sport Drs. Hilton and Lundberg

reviewed eleven published, peer-reviewed original

studies in male individuals identifying as transgender

who had undergone at least 12 months of testosterone

suppression. They found a unified consensus that

muscle mass and strength measurements remained

far higher than in female reference subjects. Hilton &

Lundberg, Female Category of Sport. Their

A.M. case, Dkt. No. 36-6, ¶ 3.2, citing Gershoni and

Pietrokovski, 2017. The landscape of sex-differential

transcriptome and its consequent selection in human adults.

BMC Biology 15(1): 7.

31 A.M. case, Dkt. No. 36-6, ¶ 4.5.

30

23

conclusions were supported by transgender runner

and scientist Joanna Harper in a second review of the

same dataset who concluded while “hormone therapy

decreases strength, LBM and muscle area, yet values

remain above that observed in cisgender women, even

after 36 months.” 32

In another recent study, boys self-identifying as

girls who had received puberty blockers from around

13 years of age, then cross-sex hormones at 16 years of

age grew to an average adult height (180.4cm) far

larger than the population female average (170.7cm)

and closer to the population male average (183.8cm). 33

III.

Sex Separation is Essential to Preserving

Female Opportunities in Sport

A.

A Category for Female Athletes

Based on Sex is How Women

Participate in Sport Equally to Men

The only way sport can be fair and equal for

women is with a protected women’s category that

excludes competitors with male advantage. Title IX

was enacted in part to advance just such sex

separation in sport that advances women.

Harper et al., 2021. How does hormone transition in

transgender women change body composition, muscle strength

and haemoglobin? Systematic review with a focus on the

implications for sport participation. British Journal of Sports

Medicine 55(15): 865-872.

33 Boogers et al., 2022. Trans girls grow tall: adult height is

unaffected by GnRH analogue and estradiol treatment. Journal

of Clinical Endocrinology and Metabolism.

32

24

The crowning achievement of Title IX has been

its capacity to propel women to success in male

dominated businesses. 34 The reason for this, of course,

is because Title IX’s raison d’etre has always been to

fight discrimination against women. This rationale is

turned on its head, however, by efforts to convert the

statute into means by which girls are required to face

boys in competition to remedy boys who identify as

transgender allegedly having been discriminated

against.

Title IX cannot simultaneously do two things at

once. It cannot both provide opportunities to girls in

sport at the same time it schizophrenically enables

boys to compete against and displace girls,

particularly when the very biological factors which

justified Title IX’s embrace of sex-separation in sport

persist.

34 See “Ernst & Young Studies The Connection Between Female

Executives And Sports,” (“90% of the women surveyed had played

sports . . . with this proportion rising to 96% among C-suite

women”),

available

at:

https://www.forbes.com/sites/alanaglass/2013/06/24/ernst-youngstudies-the-connection-between-female-executives-andsports/?sh=7338319633a2;

Stevenson,

B.,

“Beyond

the

Classroom: Using Title IX to Measure the Return to High School

Sports,” National Bureau Of Economic Research (“a 10percentage point rise in state-level female sports participation

generates a 1 percentage point increase in female college

attendance and a 1 to 2 percentage point rise in female labor force

participation . . . greater opportunities to play sports leads to

greater female participation in previously male-dominated

occupations”),

available

at:

https://www.nber.org/system/files/working_papers/w15728/w157

28.pdf.

25

It would be nice if Title IX were magic dust to

be sprinkled on two problem to make both go away.

Title IX is instead, however, a statute drafted to

protect women and girls, that uses terms such as

“women,” “men” “girls” and “boys” with fixed meanings

rooted in biology and what English language

dictionaries for centuries have said they mean. Only if

those terms are given their fixed, original meaning can

the statute do its job and only if Title IX is interpreted

as protecting “women” and “girls” will it cease being a

sword that harms them.

Only if Title IX is interpreted correctly will it

confer the benefits Amici have experienced as Title IX

was intended to do and long did so well, providing

opportunities to girls and women, helping them

overcome discrimination, prosper and succeed.

B.

Without Protection of the Girl’s

Category Girls Will Drop Out of

Competitive Sport

Amici Janel Jorgensen McArdle explained that

had she been confronted with doping in her sport

before she reached the Olympics she likely would have

dropped out and expects this may happen to girls

forced to compete against boys. Her concerns are

substantiated by reports of women in other sports who

chose not to compete against males because they

understand they “have zero chance, so what is the

point of wasting our money on registration fees?” 35

See, e.g., https://quillette.com/2022/09/28/is-this-the-liathomas-of-disc-golf/.

35

26

C.

Requiring Sport to Accept Eligibility

Rules Not Based on Objective

Criteria Harms Both Women and

Sport

Fixed rules are “fundamental in representing

the boundaries of fair sporting competition.” 36 To

facilitate competitive fairness, increase sport

opportunities and protect the safety of athletes,

objective sport eligibility rules such as age limits,

amateurism rules, anti-doping rules, paralympic

disability classifications, qualifying standards, senior

classifications, weight categories and sex-based

categories are essential.

Until recently objective rules have not been

considered subject to an athlete’s decision to opt out of

compliance. Wrestlers and boxers for instance are still

not able to self-declare their preferred weight class.

Adults may not compete in junior categories no matter

how unskilled the adult or how much better it might

make them feel to compete with the children they may

wish they were. Yet, whenever objective criteria are

abandoned in favor of self-defined entry criteria the

results tend to be unfair, administratively

unworkable, and destructive to sport. 37 The same is

true for allowing males to self-designate into the

36 Handelsman, et al., Sex Differences in Athletic Performance,

p. 806.

37 For instance, the former head of the International Paralympic

Committee (IPC) recently called for reform to save the integrity

of the Games due to Paralympians self-declaring disability. See

https://www.abc.net.au/news/2023-04-03/paralympic-gamesclassification-system-exploited-australian/102165924.

27

female category.

CONCLUSION

This Court should grant the Petitions for Writs

of Certiorari.

Respectfully submitted,

WILLIAM BOCK, III

Counsel of Record

KROGER GARDIS AND REGAS, LLP

111 Monument Circle Ste 900

Indianapolis, Indiana 46204

(317) 777-7412

wbock@kgrlaw.com

Counsel for Amicus Curiae

August 14, 2024