Thread by @KirstiMiller30

There is no relationship between unaltered endogenous testosterone and sport performance. None.

I know. Surprising, right?

Also, there's complete overlap of testosterone values for cis males and cis females.

In statistics, 'complete overlap' means, in this case, that the BOTTOM of the male range is the same as the BOTTOM of the female range (near 0), but the TOP of the female range doesn't quite extend to the TOP of the male range.
biomedware.com/files/document…

And guess what!

Low testosterone elite men are statistically OVERrepresented in elite male sport.

0.5% of ELITE male athletes were naturally below the average for cis female athletes.

& 25% of ELITE cis male athletes are below the current 10nmol/L cutoff for female athletes.

Wait!

This means that for ANY TESTOSTERONE POLICY you pick to exclude 'men' from women's sport WILL. NOT. WORK.

There will always be some elite cis males naturally below that level.

SCIENCE!!

In fact, there is no clear biological list of features that allow us to even remotely cleanly separate men from women.

Chromosomes? NOPE

Testosterone? NOPE

Height? NOPE

Look at height! Also complete overlap. In fact, in the sample of elite athletes, the shortest athlete was a man!

This kind of complete overlap between genders is true for any and ALL physiometric characteristics you can pick.

I hope you can see a clear pattern emerging.

First, there's complete overlap for every feature.

Second, the RANGE within a single sex is much much wider than the AVERAGE DIFFERENCE between sexes. Like, a LOT wider.

So the difference between the shortest and the tallest woman will be in the area of FEET, but the average differences between men and women are measured by INCHES.

This is true for all physiometric characteristics.

Assessing any group of athletes as a monolithic group especially amongst trans athletes is flawed. Trans is an umbrella term many different body types & stages of transition. Blanket inclusion or exclusion does not work.

https://twitter.com/kirstimiller30/status/1408351509964738561?s=21

Trans & Intersex athletes advantage ~ Myth 101.

They have a man's body, their bone structure and bone density gives them an unfair advantage.

https://twitter.com/kirstimiller30/status/1268466252780982273?s=21

Despite the many assumptions about the relationship between testosterone and athletic advantage, there is no evidence showing that successful athletes have higher testosterone levels than less successful athletes.

https://twitter.com/kirstimiller30/status/1402593014896218113?s=21