`The distinction between “finding no evidence of advantage” and “proving no advantage exists” is real. It is also the distinction that separates “more research” from “blanket ban.”'
I read the BJSM review because the results were somewhat surprising. After looking at things a bit, I'm really hesitant to say that we're comparable to cis women, athletically, based on this review. The technical phrase `[n]o significant differences' is the term used in the paper that people are pointing to to say that TW and CW perform the same but it's really easy to misinterpret. It just means that, as you point out, from a mathematical standpoint the data does not indicate a difference, not that there is no difference.
So based on a short review of paper...
Bad news: Get rid of an outlier study used in the meta analysis and the review indicates that for athletic pursuits primarily involving strength, TW will have an advantage over CW. Good news: For athletic pursuits that require endurance TW's strength advantage would likely be offset by inability to use that strength (i.e., it would wane during competition). So this issue needs to be studied on a sport-by-sport basis and blanket bans are likely unfair or even unnecessary to protect/ensure fair play for CW. This is more or less inline with what trans sports researcher, and competitive runner, Joanna Harper has found.
The conclusions drawn around the variables we care about (upper-body strength, lower-body strength and VO2 max) for TW vs. CW all have a GRADE of `very low', which means `We have very little confidence in the estimate effect: The true effect is likely to be substantially different from the estimate of effect.' Those same variables for TW vs. CM have a GRADE of `moderate', which means `The true effect is likely to be close to the estimate of the effect, but there is a possibility that is substantially different'. So the data shows we can be pretty sure there's a difference between TW and CM (duh) but not that there isn't a difference between TW and CW (ugh).
From Figure 2 in the review, it seems pretty clear to me that the Alvares et al. (2025) study is an outlier that is pulling the data towards uncertainty over effect; i.e., get rid of that study and it looks like TW do have greater upper- and lower-body strength but CW have slightly better VO2 max.
That Alvares et al. study compares seven TW with eight CW, so a very small pool from which to draw conclusions. When I look at the descriptive data of the participants it's apparent that the TW are at least slightly older, smaller (height/weight), and have significantly higher estradiol levels and significantly lower testosterone than the CW. Unsurprising to most of us then that that study would show CW have greater upper- and lower-body strength compared to TW.
The anti-trans side likes to represent TW like we have the same abilities as CM and the review definitely disproves that idea, but it also seems to indicate that we're not exactly at the same level as CW either.
None of this is scientific and treating people encouraging bans as if they are engaging in good-faith is naive. The "scientists" looking for justifications to discriminate are not engaging in science. It's politics looking for justifications to violate human rights. If they could get away with it, these same people would make racially segregated leagues with the exact same justifications.
`If they could get away with it, these same people would make racially segregated leagues with the exact same justifications.'
Sure but they do sound plausible to most people who are unfamiliar/unacquainted with trans people/issues. If we can reach those people then we can marginalize the anti-trans position.
Oh, have to hear this. Is it possible sexual assault from trans athletes towards the female athlete? Oh, right.. that couldn’t be it. Wonder what it could be?
This is an issue that affects hundreds of people and sparks a backlash that affects hundreds of millions. Let it lie.
This is not the biggest injustice in the world, or close to it. A lot of people can't play competitive sports, for a lot of reasons. It is not a human right.
Great piece, Ari. Especially liked this:
`The distinction between “finding no evidence of advantage” and “proving no advantage exists” is real. It is also the distinction that separates “more research” from “blanket ban.”'
I read the BJSM review because the results were somewhat surprising. After looking at things a bit, I'm really hesitant to say that we're comparable to cis women, athletically, based on this review. The technical phrase `[n]o significant differences' is the term used in the paper that people are pointing to to say that TW and CW perform the same but it's really easy to misinterpret. It just means that, as you point out, from a mathematical standpoint the data does not indicate a difference, not that there is no difference.
So based on a short review of paper...
Bad news: Get rid of an outlier study used in the meta analysis and the review indicates that for athletic pursuits primarily involving strength, TW will have an advantage over CW. Good news: For athletic pursuits that require endurance TW's strength advantage would likely be offset by inability to use that strength (i.e., it would wane during competition). So this issue needs to be studied on a sport-by-sport basis and blanket bans are likely unfair or even unnecessary to protect/ensure fair play for CW. This is more or less inline with what trans sports researcher, and competitive runner, Joanna Harper has found.
The conclusions drawn around the variables we care about (upper-body strength, lower-body strength and VO2 max) for TW vs. CW all have a GRADE of `very low', which means `We have very little confidence in the estimate effect: The true effect is likely to be substantially different from the estimate of effect.' Those same variables for TW vs. CM have a GRADE of `moderate', which means `The true effect is likely to be close to the estimate of the effect, but there is a possibility that is substantially different'. So the data shows we can be pretty sure there's a difference between TW and CM (duh) but not that there isn't a difference between TW and CW (ugh).
From Figure 2 in the review, it seems pretty clear to me that the Alvares et al. (2025) study is an outlier that is pulling the data towards uncertainty over effect; i.e., get rid of that study and it looks like TW do have greater upper- and lower-body strength but CW have slightly better VO2 max.
That Alvares et al. study compares seven TW with eight CW, so a very small pool from which to draw conclusions. When I look at the descriptive data of the participants it's apparent that the TW are at least slightly older, smaller (height/weight), and have significantly higher estradiol levels and significantly lower testosterone than the CW. Unsurprising to most of us then that that study would show CW have greater upper- and lower-body strength compared to TW.
The anti-trans side likes to represent TW like we have the same abilities as CM and the review definitely disproves that idea, but it also seems to indicate that we're not exactly at the same level as CW either.
Really enjoying the posts!
None of this is scientific and treating people encouraging bans as if they are engaging in good-faith is naive. The "scientists" looking for justifications to discriminate are not engaging in science. It's politics looking for justifications to violate human rights. If they could get away with it, these same people would make racially segregated leagues with the exact same justifications.
`If they could get away with it, these same people would make racially segregated leagues with the exact same justifications.'
Sure but they do sound plausible to most people who are unfamiliar/unacquainted with trans people/issues. If we can reach those people then we can marginalize the anti-trans position.
I don’t think any number of “studies” is going to cut it when it’s black and white.
Oh, have to hear this. Is it possible sexual assault from trans athletes towards the female athlete? Oh, right.. that couldn’t be it. Wonder what it could be?
This is an issue that affects hundreds of people and sparks a backlash that affects hundreds of millions. Let it lie.
This is not the biggest injustice in the world, or close to it. A lot of people can't play competitive sports, for a lot of reasons. It is not a human right.