Anyone wishing to spot changes from our pre-print:
1. We included a section on pre-pubertal differences (that is, even young boys outperform young girls, thus the performance gap is not solely down to pubertal T).
2. We extended our analysis of CV capacity changes and potential impact on endurance performance (although we had acknowledged a likely effect, we have drilled deeper into mechanism).
3. We have *significantly* extended our discussion of impact on athlete transwomen and the mitigating effects of exercise (that is, moderate training can mitigate or even reverse muscle/strength loss during T suppression).
The remaining differences are minor, and represent no significant change from the pre-print.
Several people argue that if the metrics of a trans-identified male fall "within female range", it is fair for that male to compete in female sport.
But we need to look at what's typical .v. what's exceptional.
Male traits often overlap with female traits. Height, muscle mass and so forth all generate normal distributions within sex (bell curves), where the lower end of the male range overlaps with the upper end of the female range.
This is a computer-generated series, transitioning between "hyper male" and "hyper female".
Where does your perception of the sex of the person shift?
Which face is the most ambiguous?
If you reply, please include your sex (the actual one).
OK, in the paper, the data was:
Faces 1-3: 100>97% scored "male"
Faces 5-7: 94>100% scored "female"
Face 4 was the transition face, with 68% scoring it "male".
FTR, I didn't hesitate on 4/male then 5/female.
Next set: same series, now skinned 🤣
I won't ask for responses. It is probably obvious that people were less able to detect any sharp transition from male>female, from face-on bone structure.
Note to archeologists: this doesn't mean you can't tell a male from female face, so stop pretending you can't.
In defence of Semenya et al, many argue: 1. athletes with 5ARD are female; 2. features associated with 5ARD are normal female variation; 3. these athletes should be included in female sports.
The first claim is incoherent.
To understand 5ARD, let's look at healthy reproductive development.
Both male and female development are well-understood.
Male development 1. Y chromosome carrying functional SRY that directs testes development 2. testes produce hormones, notably testosterone (T) 3. T first drives male internal genitalia development 4. T>DHT conversion drives male external genital development