Bengaluru: Women’s boxing at the 2024 Paris Olympics has come under a cloud after the Algerian boxer Imane Khelif’s stunning 46-second win over Italy’s Angela Carini. Since the match, accusations have followed the Algerian about her sex and gender.
Taiwanese sensation Lin Yu-Ting became the second boxer at the centre of the Olympics gender row after she beat Bulgaria’s Svetlana Staneva, who made a cross with her fingers as she left the arena, an apparent reference to the double XX chromosome of a woman.
Both Khelif and Yu-Ting are poised to win medals.
What is the controversy, and what does the science behind hormones and chromosomes say? ThePrint explains.
What is the controversy with Khelif?
Khelif has been accused of being “male”, owing to her muscular appearance and high testosterone levels. She is also accused of having XY chromosomes, which are the sex chromosomes of biological males.
What does testosterone do in humans?
Testosterone is the primary male sex hormone, but is also produced in women. It is associated with improved bone, muscle and hair growth. But it is also involved in metabolism, cardiovascular system maintenance, mood regulation, cognition and social behaviour.
Excess production of testosterone occurs in both men and women. In women, it leads to irregular or absent menstruation, male-pattern body hair growth (hirsutism) and muscular development, while in men, it manifests as acne, hair loss on the scalp (alopecia), increased facial hair and increased aggression.
It occurs in approximately up to 10 percent of women worldwide, and is often caused by polycystic ovary syndrome (PCOS).
The hormone is also prevalent in cases of differences in sex development (DSD), which are congenital disorders of the reproductive system. DSD results in having atypical chromosomal, reproductive (gonadal) or anatomical sex organ development.
Owing to the muscular development it facilitates, women with high testosterone are often athletic, and it’s thus more prevalent among female sportspersons.
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How does testosterone play a role for female athletes at the Olympics?
In 2011, the International Olympic Committee and World Athletics (international governing body for athletics) released new conditions restricting the eligibility of female athletes with hyperandrogenism, whether DSD is prevalent or not. In 2019, these regulations were revised to focus on DSD.
What sex tests are athletes subject to?
Female athletes are tested biologically using a chromosome test or testosterone test.
What sex or hormonal tests are male Olympic participants subject to?
None.
Just like testosterone, both sexes also produce oestrogen and progesterone. In men, oestrogen is required to produce sperm, and low oestrogen can result in erectile dysfunction or low muscle mass. Progesterone is also required in the male body to produce testosterone, and low progesterone levels can lead to the same symptoms of low oestrogen and low testosterone levels.
However, male athletes do not have an upper limit on the traditionally female hormones oestrogen and progesterone. They also do not have an upper limit on testosterone, which has the potential to increase strength in male athletes, too.
A 2014 study found that among nearly 700 elite athletes, over 16 percent of men had low testosterone levels, while 13 percent of women had higher levels, with a “complete overlap between the two sexes.”
Does Khelif have XY chromosomes?
There is no evidence that Khelif has XY chromosomes. The rumours first began in 2023, after Khelif defeated Russian Boxer Azalia Amineva at the World Boxing Championships. After the match, the Russian-dominated International Boxing Association (IBA) said that Khelif had undergone “tests” and had failed them with XY chromosomes. The IBA refused to disclose even to Khelif what the tests were. The same year, the IBA was stripped of its status as the world amateur boxing governing association by the International Olympic Committee over alleged financial irregularities and questions about the integrity of officials. Khelif has not officially undergone a chromosome test that has been made public.
What are chromosomes, and what does XY combination do?
Every normal biological human cell contains 23 pairs of chromosomes. Of these, 23 chromosomes are inherited from the mother, and 23 from the father. Within chromosomes are genes which, in turn, contain all our DNA. The X chromosome houses about 1,000 genes, while the Y chromosome contains less than 20.
Typical biological females have XX chromosomes while typical biological males have XY chromosomes. In the Y chromosome sits a gene, called the SRY (sex-determining region Y protein) gene, that decides whether the foetal gonads develop into male testes. However, newer studies point to the presence of more than one gene involved in embryonic sex determination.
The sex organs then go on to produce hormones, which then affect the development of the rest of the cells. Ambiguous genitalia develop in one in 4,500 infants.
Genetic variations occur because genes constantly make mistakes when DNA is copied. There are multiple disorders like producing extra (or half) copies of chromosomes, resulting in chromosomal combinations such as X, XXX, XXY, XYY, XXXX, XXXY, and XXYY, among others. Typically, those with the Y chromosome are born with biologically male organs, although there are exceptions wherein some are born with female organs.
Women with X and Y chromosomes can also produce low testosterone. In 1996, one of the only years when the IOC released chromosomal testing data, seven of eight women with X and Y chromosomes were androgen-insensitive. This means their body cannot detect or utilise the testosterone being produced.
Mammals have the XX/XO (O signifies the lack of a Y chromosome) and XX/XY chromosomes, birds and reptiles have ZW/ZZ, insects ZZ/ZO, and plants XY and UV chromosomes.
Birds and reptiles with ZW chromosomes are females, while those with ZZ are males. UV chromosomes are mating-type chromosomes, where U is a female gamete and V is a male gamete.
Can women with XY give birth?
While XY is generally associated with male genitalia, there have been instances of XY female individuals who have menstruated and given birth. Chromosomal testing is largely entirely absent outside of medical societies and sporting events, especially in rural areas of the ‘Global South’. Therefore, there is a lack of data on abnormal chromosomal combinations and reproductive health of XY women.
Are chromosomal tests performed for Olympic athletes?
All female athletes underwent mandatory sex verification testing from 1958 to 1992, and those who “passed” were provided femininity certificates. Chromosome testing was last performed in 1996. Mandatory sex testing for the Olympics was banned in 1999 but is still practised for some athletes.
Multiple female athletes — hurdler Maria Martinez-Patiño (Spain), sprinter Ewa Kłobukowska (Poland), swimmer Pratima Gaonkar (India), sprinter Santhi (India), runner Caster Semenya (South Africa), runner Pinki Pramanik (India), Dutee Chand (India), and runner Annet Negesa (Uganda) — have all failed gender tests due to the presence of a Y chromosome, and have been disqualified or have had their medals revoked.
A number of them, prominently Chand, have had subsequent legal victories, granting them recognition for their athleticism, and dismissing testosterone and chromosomal testing as unscientific.
Are trans people allowed to participate in the Olympics?
It depends on various governing authorities and global sport federation bodies whether trans people are allowed to participate in the Olympics. But female-to-male trans athletes face no restrictions, while male-to-female athletes are required to suppress their testosterone levels.
The IOC announced in January this year that transgender and intersex athletes’ eligibility is left up to the discretion of their own countries’ governing bodies and international sports federations. However, the regulations also say that athletes can be excluded where there is “a demonstrated disproportionate advantage and/or safety risk”.
In Algeria, being transgender is illegal.
What is a disproportionate advantage in sports?
A disproportionate advantage, as defined by the testosterone regulations, refers to an inherent biological advantage that women with higher levels of the hormone have over other female athletes. Testosterone is known to indeed offer an advantage. In her book The Day I Became a Runner, author Sohini Chattopadhyay writes that the Court of Arbitration for Sport (CAS) and the World Athletics agreed that testosterone offers an advantage in athletic performance.
It leads to higher lean body mass in men and more muscle mass in women. Comparison between elite male and elite female athletes (with “regular” testosterone levels) found that there was a 10 to 12 percent improved athletic performance in males compared to females, thus resulting in male and female categories based on testosterone levels.
However, Chattopadhyay explains how increasing testosterone in women to a level equivalent to the average male athlete does not result in a 10 to 12 percent improvement in performance.
There are also other forms of inherent, biological and congenital physical advantages that individual athletes often possess.
American swimmer Michael Phelps is often referred to as a genetic freak of nature because of his physical features. His wingspan — the distance between his arms when spread open in a T shape — is longer than his height, giving him a greater propelling advantage during swimming.
His body also produces a mere two-thirds of the amount of lactic acid other athletes produce at the end of an event, offering anti-inflammatory and faster healing advantages at the muscle and tissue level. His palms and feet are also larger than average; his size-14 feet can bend 15 degrees more than others, and displace more amounts of water at every stroke than other swimmers. He is also double-jointed, which offers more flexibility.
Chinese basketball player Yao Ming is 7 feet 6 inches tall, an inherent advantage in the sport.
André the Giant, the famous French wrestler, suffered from gigantism, which caused his body to produce excess growth hormones.
Former Finnish skiing champion Eero Mäntyranta won silvers at four Olympic Games. He had a rare mutation in the EPOR gene, which boosted red blood cells and haemoglobin, offering him a 50 percent higher oxygen circulation advantage compared to other athletes.
Matthias Schlitte, a German arm-wrestling champion, was born with a genetic defect called Klippel-Trenaunay-Weber syndrome, a condition that affects the development of blood vessels, soft tissues and bones. This led to bone and tissue to overgrowth only on his right arm. He has won tournaments since age 17 with hardly any training.
Retired Jamaican sprinter Usain Bolt’s long legs give him larger strides, and many believe that his “running” gene ACTN3 offers him an advantage, especially as it is nourished by Jamaica’s aluminium-rich soil.
American archer Brady Ellison has above-average vision, being able to see from 20 feet away what most people can only see from 10 feet. He is nicknamed ‘The Prospector’ due to his ability to win gold at the Olympics.
When Indian runner Dutee Chand went to court against her sex testing disqualification, experts argued that there were more than 200 biological abnormalities that can offer competitive athletic advantages, including increased aerobic capacity, large hands and feet, increased fast-twitch muscle fibres (similar to Usain Bolt), long arms or legs, faster healing and resistance to fatigue, and more.
However, these physical traits that induce inherent advantages are not regulated, especially in male athletes.
Why are Olympic testing criteria contentious?
Olympic testing criteria are contentious because they are implemented only for female athletes, and are overwhelmingly skewed against women of colour from poorer nations. Testosterone testing has been implemented for female athletes, particularly in track and field. For instance, runners Santhi, Chand and Semenya, among others, have been subject to testosterone testing and involved in legal battles on competing legitimacy.
Olympic testing for women first became a regulation in the 1936 Olympics held in Nazi Germany, about a decade after women began competing. The policy allowed the authorities to eliminate any “suspicious” female athlete, with no definition of criteria for intervention.
In 1966, the testing became systematic for all female athletes, requiring them to strip completely in front of a panel (a “peek and poke” test), who would confirm that the athlete looked like a biological woman with the right sex organs.
Two years later, chromosome tests were introduced and mandated for women, and persisted until 1999.
No such biological sex test has been administered on record to male athletes to detect XX chromosomes. Rose Eveleth, the host of Tested, an audio documentary on the century-long history of sex testing in sports, said last month that the chromosomal tests immediately led to medical experts denouncing the method as being scientifically unsound, resulting in a 30-year medical campaign to eliminate the testing.
Throughout its history, sex testing in Olympics has resulted in female athletes modifying their body through surgery or medication to remove abnormal genitalia and lower hormones.
What are celebrities like JK Rowling and Elon Musk saying?
Anti-trans voices online, including Rowling and Musk, have amplified unverified claims of Khelif having XY chromosomes. They insist that the chromosomes make Khelif biologically male.
However Khelif and other female athletes who have tested high for testosterone have been born with biologically female sex organs, which Rowling and Musk also define as female by default.
(Edited by Radifah Kabir)
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