Preface: I've written this post to provide information that I hope will be of use to others in general conversations, and also because I think it could be particularly helpful to those in the USA making formal comments to the Biden administration objecting to its proposed changes to Title IX regulations.

For those unware: the new regulations that the Biden admin has proposed would make it illegal for educational institutions in the USA that receive federal funds to bar all males from girls and women's school and interscholastic sports across the board. According to Biden's new rules, males who claim to "identify as" as girls or women, or as "non-binary" - or as some other newfangled, yet-to-be-invented way that shows they do not see themselves or want to be perceived as "cisgender" - would have to be permitted to participate and compete in girls' and women's school sports at all grade levels, unless it has already been proven or can be proven that their participation will create unfairness or safety risks. The Biden admin's new Title IX guidance and regulation say that assuming a TIM or other male with a novel gender identity who wants to participate in girls' and women's school sports has an unfair advantage, would create a safety risk, or both, simply because he is male constitutes unlawful discrimination against him under Title IX.

Now to the main points of this post:

In recent years, a great deal of attention has been paid to the thorny issue of whether it's fair for trans-identified males like Lia Thomas and XY DSD athletes like Caster Semenya to seek and be granted "inclusion" in girls' and women's sports.

Underlying the general discourse and many policy decisions about "inclusion" - or rather, intrusion - of TIMs and XY DSD athletes in the female category is the widely-held assumption that prior to puberty of adolescence, human males and females are equally matched in physical abilities and boys have no natural advantages over girls.

A corresponding assumption is that all the physical features that adult and teenage males acquire during puberty of adolescence which give them such a large and overwhelming advantage over females in nearly all sports come about because of the massive amounts of testosterone that the male gonads, the testes, continually pump out starting when boys begin male puberty of adolescence.

Because of these assumptions, many people nowadays take it as a given that until kids are age 12 or so, there's no need for there to be sex segregation in sports - boys and girls can play and compete with and against one another fairly and without causing any undue extra safety risks for the girls.

Similarly, these assumptions cause many "trans advocates" and those who are uninformed and in the "be kind" camp to believe that when youth sports are segregated by sex,

1. it's fair and safe for trans-identified males to play and compete in girls sports throughout childhood to age 12 or Tanner Stage 2; and

2. after reaching age 12 or Tanner 2, TIMs should be allowed to continue playing and competing in girls' and women's sports so long as they have started "puberty blockers" to stop their testicles from pumping out testosterone and so long they stay on those drugs, or undergo surgical castration, to insure that they never experience any aspect of male puberty that is caused by male levels of testosterone.

According to the reasoning that's often employed today, trans-identified males who haven't been "androgenized" by high levels of gonadal testosterone during male puberty of adolescence don't have or develop any of the multitude of physical characteristics that combine to give teenage boys and grown men such huge advantages in sports over girls and women. Therefore, the reasoning goes, any trans-identified male whose production of testicular testosterone was shut off by use of "puberty blockers" starting when he was 11 or 12 - and whose testicular T remains shut off through the rest of his formative years by continued use of T-suppressnt drugs and/or surgical removal of his testicles - should have free rein to participate and compete in girls and women's sports when's he's of the age for junior high, high school, college/uni and the rest of his life.

But are these widely-held assumptions actually true?

Academic papers, op-eds and reporting published in recent decades by sports sociologists and even some sports scientists continually assert that there are no differences in the sports abilities and performance levels of males and females prior to puberty of adolescence.

But all the youth sports records from countries, states, regions, clubs, leagues, associations around the world that go back in some cases to the 1940s and 50s tell a very different story.

Yes, once boys begin puberty of adolescence, the male-over-female advantage in sports becomes so huge and overwhelming that it leads to a performance gap between teenage and adult males and females in nearly all sports so glaringly obvious that it can't be denied.

But a measurable and significant - albeit much smaller - male-over-female advantage and sports performance gap exists prior to puberty of adolescence too. This is one of the reasons why even at the earliest ages of sports such asTee-ball and pee wee soccer for kids ages 3 and 4, sex segregation is common and often routine. Not the universal norm, mind you, but still very common.

All records for youth sports show that starting at the earliest ages for which sports records are kept - 6, 7 and 8 - boys consistently outperform girls in sports and sports-related physical activities in which speed and strength are the most important elements. Such as running, jumping; kicking; climbing; leaping; diving; hitting with the hands or fists; pushing; elbowing; body checking; tackling; body slamming; throwing and aiming a projectile like a ball or discus; catching a ball or other object like a frisbee flying through the air; hitting a ball, puck or other object with a bat or stick; catching a ball or other object with a stick as in lacrosse; wielding a bat or stick as a defensive and offensive weapon; doing pullpups and pushups; propelling one's body into space from a still, standing position, etc.

Little girls either match or slightly outdo young boys of the same ages only in specific activities where select trunk or core muscles and overall flexibility matter most.Such as sit-ups, leg splits, stretches, twists, and moves where the arms and hands are used to reach up, out and laterally across the body.

For example, the USATF's youth records start at 8 & under, meaning kids 7 and 8. In all track & field events - running various distances; the long jump; the shot put and mini javelin - boys in the 8 and under category and all other age divisions consistently outperform the girls.

In the mini javelin the difference is huge - the boys 8 & under USATF record is 33.29 meters (109'2¾"); the girls' 8 and under USATF record is 23.15 meters (75'11½").

https://youth1.com/track/1474168-usatf-american-youth-track-and-field-records

The records compiled over many decades by PE and rec center programs and the longstanding US President's physical fitness challenge consistently show that there's a clear-cut performance gap between boys and girls at 6 years-old or earlier.

The tables used to measure and grade participants in the US President's physical fitness challenge from the 1950s through the mid-80s show that from the earliest ages tested, which was 6, young girls did the same or slightly better than boys their same age at tasks requiring flexibility, core strength and reaching/stretching. But boys were always notably better at tasks requiring speed and strength.

Moreover, the tables showed that the peformance gap for male and female children began widening in a way that put boys way ahead in nearly all physical tasks well before the boys reached the age when they would have begun puberty of adolescence.

One mile run, 50th percentile times in minutes and seconds, 1985

6 year olds: boys 12:36; girls 13:12

7 year olds: boys it 11:40; girls 12:56

8 year olds: boys 11:05; girls 12:30

9 year olds: boys 10:30 girls 11:52

10 year olds: boys 9:48; girls 11:22

11 year olds: boys 9:20; girls 11:17

85th percentile figures from 1985 for one-mile run

6 year olds: boys 10:15; girls 11:20

7 year olds: boys 9:22; girls 10:36

8 year olds: boys 8:48; girls 10:02

9 year olds: boys 8:31 girls 9:30

10 year olds: boys 7:57; girls 9:19

11 year olds: boys 7:32; girls 9:02

Flexed arm hang, in seconds, 1985

6 year olds: boys 6; girls 5

7 year olds: boys 8; girls 6

8 year olds: boys 10; girls 8

9 year olds: boys 10; girls 8

10 year olds: boys 12; girls 8

The tables I'm citing can be found here.

https://medium.com/in-fitness-and-in-health/the-presidential-fitness-test-553c0c05710b

And here: https://legionathletics.com/presidential-fitness-test/

The only exception to the general rule of boys consistently outperforming girls in sports from the earliest ages for which records are kept is swimming.

Whilst boys usually outperform girls in swiming overall, sometimes in the lower age ranges, the best girls are as fast or faster than the best boys.

For example, the world record freestyle 50-meter times for girls age 6, 7 and 8 are faster than the world record times for boys of those ages. In all other age groups, the boys' record times are faster than the girls' record times, but not at 6, 7 and 8.

WORLD RECORDS FREESTYLE 50 METRES (50 m pool), BOYS & GRLS AGES 5 through 17

Age 5 - Boys: 42.66; Girls 43.17

Age 6 - Boys: 36.27; Girls 35. 86

Age 7 - Boys: 32.44; Girls 32.09

Age 8 - Boys 30.38; Girls 30.34

Age 9 - Boys 28.73; Girls 28.85

Age 10 - Boys 26.69; Girls 27.95

Age 11 - Boys 25.94: Girls 26.98

Age 12 - Boys 24.59: Girls 25.73

Age 13 - Boys 23.36 ; Girls 25.35

Age 14 - Boys 22.73; Girls 24.74

Age 15 - Boys 22.60; Girls 24.13

Age 16 - Boys 22.22; Girls 24.13

Age 17 - Boys 21.83 Girls 23.99

http://age-records.125mb.com/swim.htm

Moreover, the records for some schools, swim clubs and state and national organizations show that pre-pubsecent girls sometimes have an edge over boys of their same age girls in two particular strokes - backstroke and butterfly.

In this swim club in Pennsylvania in the USA, for example, the record times for the boys in the under 8 category are faster than the record times for under 8 girls in all strokes except backstroke and butterfly.

https://www.waswim.org/8andUnderRecords.html

Fiinally when girls who swim competively get to age 10, 11, 12, they sometimes outperform boys their same age in various strokes and races.

This probably because girls those ages already will have started or be well into female puberty of adolescence and already have had or are undergoing their major growth spurt. Moreover, girls fairly early in puberty will already have put on the extra layer of adipose tissue under the skin all over the body that gives girls and women more buoyancy - a big plus in swimming. By contrast, boys those same ages usually are still pre-pubsecent and several years' shy of their major growth spurt, which in males occurs much later than in females. Finally, boys never develop the extra layer of fat all over their bodies that's a boon in swimming like girls do. At 10, 11, 12, 13 most boys who do sports are very skinny.

Also, it's important to note that swimming is unique amongst sports in that it takes place in water, where different rules of physics apply. By contrast, other sports take place on land, or on land and in the air.

For anecdotal evidence that boys outperform girls in sports from the earliest ages, and this is so even when they "identify as" girls and are put on "puberty blockers" starting at age 11, there's the case of former "trans poster child" Jazz Jennings.

Starting when Jazz was in pre-school, Jazz's horrible parents Greg and Jeanette used lawsuits, or the threat of lawsuits, to insure that Jazz would always get to play girls' community and school sports. Jazz played girls' soccer, lacrosse and some other girls' sports until he was at least in his mid-teens. On recent seasons of Jazz's TLC television show, "I Am Jazz," now-adult Jazz has looked back on Jazz's younger years in girls's sports wistfully, saying "I was always the best one on every team" that Jazz played on or against.

When Jazz says this, he appears to think he's simply making an observation that prior to becoming morbidly obese as a young adult, Jazz had demonstrated real talent at sports - something Jazz seems to think reflects well on him personally. Jazz is utterly clueless that when others hear him boast about "always being the best one" in all the girls' sports he played growing up, we hear what he's saying very differently. We hear Jazz tactily admitting that the reason he always excelled in youth sports is because he was a male who always competed in the female category, against actual girls.

When Jazz boasts to the TV cameras about how he was "always the best one" in all the girls' sports he did as a child and teenager, Jazz is also bringing attention to the fact that in each and every girls' sport he played growing up, his status as " always the best one" meant that no girls Jazz played with or against were ever given the chance of being "the best one." The sense of personal pride, shots of self-esteem and happy memories that Jazz derived from "always being the best one" in girls' sports growing up came at the direct expense of all the girls Jazz played with and against. Think of the wonders it would have done for the self-esteem of the female teammates and competitors that Jazz always outshone and trounced if just every once in a while, they could have had a shot at being "the best one" too. But no, that wasn't in the cards for Jazz's female teammates and competitors. None of them got the chance to shine and be hailed as "the best one" because Jazz's awful parents went to great lengths to insure that the honor of "always being the best one" in girls' sports in their neck of the woods in Florida would go to their special son.