Episode 97: The 2D:4D digit ratio

Music

Tom, look at your hand.

All right, I'm looking at it. Which one? Does it matter which one?

Well, we'll come to that, but just pick a hand, look at your hand.

Pick a hand, any hand, I'm going with the right hand, because that's, you know,

Okay. Now, look at your index finger and your ring finger.

Okay, the ones either side of the one that I'm giving you the middle finger

with right now, which is wrong, basically.

Yes. Which one of them is longer?

Okay, I stopped reading when I saw the top of the notes,

because I didn't want to know which was the good one.

It desired my index, my pointy finger is slightly longer, I think.

Well, I'm sad to say Tom, if you're manly and high T,

then your index finger should be relatively shorter than the ring finger.

So your 2D, your second finger should be relatively shorter than the ring finger,

4D. So you should have a low 2D, 4D ratio.

Okay.

So in your case, if you're a loser, soy boy, cock,

then the index finger is longer.

Okay. Well, that's fine.

I'm obviously now I'm tilting my fingers to the left where to make them,

so now it's definitely the other way around.

But I think I think I have to be honest.

If I put in that, it is very slightly the index finger is longer.

And I assume that will be a loser side bike.

Yeah.

You're a loser side bike.

Okay. And how about you, Stuart?

What are you?

Are you a man for a long ring finger match or man?

Anyway, welcome to this episode.

I did wonder.

The science fiction podcast.

This is a podcast that talks about controversial scientific things.

And this is kind of a fun one, but it also has a serious message about science.

Soy boys and cucks.

Well, not even, not even that, but yet that is in there too.

If you want to be a subscriber, you can become a subscriber at sciencefictionspod.com.

Yes.

Anything else?

Well, I've just sent you a picture of my fingers.

Oh, nice.

Thank you.

I'll admire them in your own time and get that with.

That was great pleasure.

Oh, yeah.

Unfortunately, mine are the same as that.

Long, longer, slightly longer index finger than ring finger.

So we're both in the soy boy cock world.

Presumably, that's a surprise to nobody, right?

Well, for all my life, like, like, I'm a big match of sports playing alpha male.

Yes.

But I'm fooling no one, right?

Yes.

Well, let's see if it matters because this episode is about the claims made by many scientists about the 2D40 ratio

which have been published for many decades.

And I think I saw someone had said that there was about 14 or 1500 papers.

Oh, peer reviewed papers published on the relations of this ratio.

The ratio of the second digit to the fourth digit, the digit ratio is on the cold.

To various different things, your personality, how you act in the real world, your sexuality,

you won't believe the number of things that this has been associated with.

Yes.

So we will come to that.

Well, yes.

My, we're going down this route again.

I'm penny twitching.

Yes.

I think basically spoilers, we are going to question this.

Press some doubt on this a little bit.

But let's talk about the, let's give the theory.

Okay.

Why would the relative lengths of your fingers be associated with anything?

Yes.

The theory is that 2D40 is a kind of quick way to measure how much testosterone exposure you had in the womb.

Right.

It is obviously quite hard to measure that, especially if someone is lost in the womb.

Yeah.

Yeah.

So, so the idea is if you're exposed to more testosterone, you'll have the lower 2D40 ratio

with a shorter index finger.

And given its caused by testosterone, it's actually a flag of all sorts of other stuff that you might expect to be caused by testosterone,

which, you know, we know that testosterone affects physical stuff and behavioral stuff too.

And it's a pretty, you know, if it, if it were true, it would be genius.

Like, it's, it is really interesting to find out our hormones affect people's, you know, behavior and the way they turn out.

Like, obviously, that's really interesting.

So if this works, great.

By the way, it sort of occurred to me like, why would it be that testosterone would make one of your fingers a different length than the other?

Like, what is the theory there?

And my understanding is that the theory is that there's different,

because of just like arbitrary, evolutionary reasons, there are different number of, of Androgen receptors in the different fingers as they develop.

And so the fourth finger has more receptors and will change more depending on the amount of Androgens or restrogens that are around in the womb.

That's the theory anyway.

No, it's actually true.

Well, yes, exactly, exactly.

But that's like, because I sort of thought, why would it be that?

Well, it's a quirk.

There's not a sort of functional reason for it or anything, as far as I can tell, an adaptational reason for it.

It's just like a quirk.

I guess in the same way that, well, I don't know if this, I don't know if this is quite the same.

But things like who being left-handed and things like that are just like quirks that happen every so often.

Although I, I had a professor who sort of described being left-handed as a kind of brain damage.

Yes.

Which I thought was quite funny.

I feel like that's, I've heard people say that's something before.

I think it's, I mean, it's like, surely, like, I think that's overstating the use of the term.

It's not, it's not helpful.

But it might be like the mildest kind of brain damage, really.

Yes.

We'll do that one of these days.

Although, I feel like I've got a lot of left-handers in my immediate family.

And this is a very interesting thing, like relating to the, you know, the different hemispheres of the brain and the sort of crossover.

Like, why does the left side of the brain control the right side of the body?

Like, what is the story there?

I think no one actually knows.

Well, there's some subset of people who have, like, who are sort of mirror images, aren't they?

Like, have their heart is on the right instead of the left.

And I think they're more like your left-handed and that sort of business.

That's interesting.

I think, I think that's true.

I might go on those things that you sort of, that we do an episode entirely disproving.

Yeah, it turns out that it's just completely, so I don't know if you've got it.

On this podcast, wall podcast, I'm very wary about, you know, giving it right.

Okay, so that's the sort of the basic theory here.

Let's look at the sort of history of this and what has been claimed for it.

So, first of all, people have known about this for a very long time.

I found a reference to a paper from 1888, like an anthropology paper.

Yeah, correct.

That's before I talked about, which talks about, like, the hand, the sort of,

the symbolism of the hand in various different cultures and all sorts of stuff.

And sort of talks about this, I found papers.

And it has been a topic of conversation.

I found papers in 1930 and 1952.

There's one.

And actually, I should say the paper that was from 1888 goes,

it refers to previous papers.

So it really does go way back.

Tom, you can read this section here.

The comparative length of the index finger has received some attention as a reverseive character.

It is usually shorter than the ring finger, as in the anthropoid apes.

Tom's equals it and rarely exceeds it.

Echo, for reasons which are not quite clear,

considers that unusual length as a progressive character.

He finds it more frequent in women and holds that it is usually correlated

with a high type of mind.

What on earth is that?

So, even in 1888, people are linking this to psychology, right?

And obviously, it was the fashion at the time to try and find physical features

that linked to psychology.

Yeah, so it's brown ridges and a lot sort of stuff.

Yeah, exactly.

Exactly.

And then Gurning recently made some 200 very exact observations to determine

whether the peculiarity had any ethnological value.

And in the main confirmed previous results,

I assume that's a bit of a race-bothering type, you know, we'll see.

I would not be surprised to get in there when that came out.

So it's been around for a while.

People have linked it to psychology for alongside,

but the guy who really got things going in terms of the current crop of 2D40 papers.

Was a chat by John Manning, who was, I believe at the time,

when he first started talking about this, which I believe was in 1998.

Okay.

Was Liverpool University, I think, now he is at Swansea.

Liverpool, of course, my alma mater, alma mater.

Right.

You were perhaps there at the same time.

Very possibly, yes, I would have been, because I was there in 2001 to 2004.

Right.

But depending on when he moved to Swansea, you were actually at the same institution as him.

He has published a lot of papers on this, like many, many, many dozens of papers,

correlating 2D40 with a wild number of variables.

And he's also, I believe he's written two books about it as well.

So he is the 2D40 guy.

Yeah, okay.

Right.

Let's talk about a few examples.

Since it's about, you know, it's about testosterone,

people have looked at it in relation to masculine traits like aggression.

So Manning and his colleagues had a paper in 2002 that correlated digit ratio

with a whole bunch of stuff.

Now, yeah, take a look at this table.

Tom, this is a table showing the correlations of digit ratio with a whole range of personality traits

and test scores.

No.

And I just want you to have a look at this.

And I don't know how many there are.

There's like, I don't know, 20 or something.

Yeah.

Down the left-hand side.

Yeah.

20 or shit.

Something like that.

And there's a little asterisk for any of these that are significantly associated with digit ratio.

I noticed a few things.

Yeah, the pee valleys are all, I mean, they bet that they're almost like they're not there at all.

Like one of them is literally one.

Like that is it is indistinguishable.

Not it is it is what you would expect to see from total randomness.

Yeah.

There's a couple.

There's there's two variables.

One that has P equals 0.03, which is sensation seeking dissenthibition, which is a part of a sensation seeking questionnaire in females own maybe no males.

And then there's the same the total sensation seeking.

So the total if you add up all the questions is has a P equals as a correlation of 0.27 with digit ratio and a P value of 0.02.

Only in females, nothing in.

Yeah.

I mean, that's yeah, that's not a lot.

I think it's about like it's it's it's it's there's two results there.

And if you I mean, they've got the whole sample, which is them added together, but you've basically split into males and females.

And so if you expect about one and 20 results to be significant.

Yeah.

And they've taken roughly 60 if you consider a whole sample, males and female.

If you if you look at the whole sample, yeah, I was thinking if you just looks at males and just look at females, then it's pretty much spot off.

Yeah.

This is that you would get these results by chance.

But in fact, we know that they've looked at even more.

So you'd expect more chance results.

I mean, one of the PIs is is exactly 0.05.

So maybe that in a in a slightly different world would be significant and would can be considered a.

Yeah.

But for a result, but basically this looks like.

There's nothing.

Yeah, this is absolute.

This is noise.

So far.

Yeah.

Of course, it's a small sample.

It needs more research blah, blah, blah.

And over time, people started to do research on it.

And a 2017 metanalysis.

Yeah.

Got 32 different studies where they measured digit ratio and correlated it with aggression as measured by different questionnaires.

I think several several several thousand people.

And I found an overall correlation of digit ratio with that particular personality trait of aggression.

With a minus 0.036.

Yeah.

So I, I, I, I, I, I dreamt of that game.

We've talked first before the game.

Guess the correlation.

That would, that would literally just look like a random mess on the screen.

But if it was on, if it was on a scatterplot.

Yeah.

It wouldn't be able to tell that from like the human.

I would be unable to distinguish it from.

Yeah.

No, it isn't the metanalysis.

It is statistically significant.

And I don't think, you know, I don't think.

I'm not a believer in dismissing small results because they are small effects because everything's made of small effects.

But I think there's a couple of things to say here.

One is, I'm not sure that an effect this big deserves the amount of attention.

No.

That digit ratio has gotten.

Put it that put one thing.

And the other thing I'd say is it's, if there's any publication bias here at all.

I think they sort of argued that there wasn't the publication bias wasn't that bad.

But come on.

Yeah.

If there's any publication bias or p hacking or anything here, then that's going to be knocked into zero pretty soon.

And in fact, we will see.

We will see some reasons to doubt even the results that are significant.

Yeah, but also a quick question.

You said this is a comment.

This is sort of you sort of implied.

I don't know if you actually mean that it's a follow-up to that 2002 manning paper.

But why would you look at that 2002 manning paper and think anything other than there is nothing here whatsoever?

I have no idea.

Yeah.

Okay.

Maybe it's just people got into the idea without that being necessarily there.

Yeah, I think that was maybe the first time that someone had done it with a questionnaire and stuff like that.

It could also be that there's other samples in that paper that they found the result in.

But then you have to compare them to the original sample where nothing is going on at all.

Yeah.

It's not perhaps you're not convinced yet, Tom.

Not 100%.

No.

So here's another one.

Economic preferences.

Okay.

The people with high testosterone people are more likely to take risks, right?

Some of the manfully long ring finger.

That's right.

That's right.

The longer ring finger, you're more likely to take risks.

And there's also studies that claim that people are sort of less reciprocal.

And you know those games where you can like give someone else money and keep some for yourself.

Oh, yeah.

It's the sort of we strike a deal thing.

But I can either give you 50%.

I can give you any share I like, but the other person can then choose to accept or reject.

And in theory, yeah.

There's all sorts of variations of it.

It's like a game theory type.

Yeah.

But in this case, I think you can just like you just like see how much people will give away and keep for themselves.

And anyway, the claim is that people with 2D40, the masculineized version are less reciprocal or less altruistic in those kind of situations.

I bet there's people who are top psychopathy.

I bet you has anyone done a study.

I haven't read ahead in the notes, but sort of feel like.

Oh, I haven't seen that, but almost.

Almost certainly.

So I would be shocked if there wasn't a study that.

And there was a famous study in 2009 in PNAS, our favorite journal, that in PNAS that found that the city of London traders.

So for American colleagues, that's like Wall Street traders.

And with more masculine 2D40s were more successful, made more money.

Now this had a massive result, a massive correlation of, you know, with some kind of measure of success.

I assume it's, you know, a amount of money in their portfolio or whatever.

A correlation of 0.482, which is like, that really is noticeable on a scatterplot, you know.

Yeah, that would definitely look like a slanty line going from bottom up.

Well, if you scroll down to him, you can see the slanty line.

I've left it in the notes.

Oh, yeah, good heavens.

So I mean, look, there's a real result for you right there.

The trouble is you can also see that it's 44 people.

Yes.

So it's not a huge number of notes.

And this has, as far as I can tell, never been replicated.

And in fact, there's a 2021 study with like thousands of people in it, where they tested thousands of people on exactly these kind of things,

on these kind of little games, where you're like, are you more altruistic to people?

How many risks do you take in a sort of economic situation?

How much reciprocity do you show and so on?

And I mean, you can look at the graph there.

And it's all completely.

That is all zero.

All of them basically.

And this is, by the way, this is like the kind of thing I like, which is not a meta-analysis.

It's a really big high quality study to test the claim.

Yeah.

Okay.

That's why I prefer.

Yeah, Stuart famously hates meta-analyses and do go in this entire episode on meta-analyses from some months ago, years ago.

Despite having published one myself, but I do have my notes.

It strikes me, incidentally, that if any part of the world, any sort of subset of the world is good at making money,

it is financial traders.

And if someone found a secret cheat for finding people who are really good at making money that was look how long their fingers are,

I suspect there would be some sort of hand-measuring bit of the entry exams at many investment banks under it.

It's like quants trading firms and stuff like that.

Yeah, I think you are exactly right.

But there isn't.

Okay.

Unless there is.

Maybe there is.

Maybe there's don't tell us.

Maybe it's all a secret thing because I want to give it.

Well, exactly.

Yeah.

Maybe they don't want too much tension drawn.

Yeah.

Maybe one quant firm knows this and gets all the people with longer ring fingers in and then.

So if this is also...

So I'm not convinced about that either.

This has also become wrapped up in the whole like.

Remember the sort of time when there were all these daft evolution psychology studies out there where they had these grand theories.

And I don't...

I'm not necessarily against the idea that there are evolved parts of the brain.

Well, I'm psychology.

I...

They just obviously are.

Be crazy not to think.

Exactly.

The brain is obviously evolved.

I mean, we've all...

Anyone who's not mad can agree that...

Or religious, I suppose.

Yeah.

They can agree that the brain is evolved.

Yeah.

There's just some incredibly obvious things.

Why do people put such a crazy value on sex?

Why do sugar taste nice?

Exactly.

Why do people ruin their lives for sex and sugar?

It completely irrationally.

The only real sort of explanation for that is surely is that these things are incredibly important in our...

Smells like sex and candy.

That's a song by the someone or others.

That's a pleasant sounding.

Yes.

A pleasant sounding thing.

Candy.

I don't mind the second one.

The first...

I'm not sure I want to know any of these things.

Yeah.

A Marcy Playground.

It's a nice...

It's a good tune.

Anyway.

Never heard of it.

Because you don't want to music stew.

Not on music.

Well, well, Tom.

I'm glad you brought that on because this is about music.

The first paper I'd like to mention.

Paper in 2000.

Here's the following...

Here's the reasoning.

The following is the reasoning in their paper.

Why did music evolve?

Well, you know, there's no adaptive reason for music to exist.

So maybe it's a way of signaling something about yourself.

And, of course, in the evolutionary psychology world,

what you signal a lot is your mating prowess.

Yep.

With our enormous peacocks' tails.

Right.

But the music is a kind of a peacock's tail for a human space.

I'm making a joke, but yes, exactly.

Well, no, you're right.

But like, this is what they claim.

And they also sit...

They say that there's evidence that women appreciate music more

while they're ovulating.

Which I could almost definitely tell you

as either not replicated or...

You know, someone never applied to that.

Exactly.

Yeah, yeah, yeah.

So the idea is that maybe men use music to impress women

and signal how manly they are.

And of course, if you're very manly,

then you've got more testosterone.

So maybe if you've got more testosterone,

then you're a better musician.

And therefore, maybe if the better musicians

would have a more rationalised 2D40, right?

That would make...

Every link in that chain makes perfect sense, doesn't it?

Absolutely perfect.

And what, obviously, explains why there's a total lack of any gay musicians.

I'm unfairly associating low T with...

low testosterone homosexuality there,

but I assume that's...

We will come to that, Tom.

We will come to sexuality.

In any case,

they say it is not possible to directly test prenatal testosterone levels of accomplished musicians.

However, the 2D40 ratio may provide an indirect test of the association, right?

So that's what they say.

And they got 70 musicians from a British symphony orchestra,

which refused to have its name...

From a style of realism.

Yeah, 54 men and 16 women

and measured their fingers

and compared the ratios to 164 non- musician controls.

And Tom, I'd like you to look at the graph

and explain it and show it...

describe it to our listeners.

I'll do my best.

Right, OK.

Let's zoom in.

So there's two charts.

There's one showing the musicians,

like bar charts of the number of them that have particular ratios

of longer index finger or long short short.

Basically, if it's on the left hand side, the graph is more masculized.

Yes, exactly.

And all of the musicians are on the left hand side of the graph

being masculine with their violins and things.

And their flutes and on the right.

On the controls are all just spread randomly around.

There's no pattern to whether they are longer index

or longer ring fingers or whatever.

That's from what I can tell.

A highly significant difference in turns out.

Now, of course, it's only in the right hand.

I don't know if they...

what the results are from the left hand.

And I just find that...

Completely unbelievable.

Every single musician had a...

Perfectly imaginable person with...

with even length, you know, in the...

Yeah, absolutely systematically.

And it's a sort of thing where it's like,

well, get someone else to replicate it then.

In another symphony orchestra, there's lots of symphony orchestras.

If it's such an obvious thing, then you should be able to find it

in other symphony orchestras too.

And in other musical groups,

trouble is, no one has ever...

Sorry, I'm aware, replicated this with another orchestra.

And the only other music 2D4D study I found looked into musical stuff

and found, perhaps, you know, encouragingly, in women,

there was a relation between having a more masculineized 2D4D

and better musical ability.

But unfortunately, for the hypothesis, in men,

it was the opposite way around.

So like, having a more feminized 2D4D was associated

with more musical ability.

I mean, let's just sound as a sort of thing.

Again, we don't know how big that study is,

but it just feels like, when you're looking at...

You see, that sort of thing is just...

I mean, you just think, oh, it's probably just noise, then isn't it?

Yes, almost definitely.

Almost definitely that.

I can't explain why it seems very unlikely that every single member of that...

Yeah.

Orchestra, the first study...

The ideal musician is Androgenous,

is the suggestion from that.

Yeah.

Yeah.

I don't know.

Now, here's the other thing, right?

This whole idea of music as signaling in this mate signaling thing...

It would imply, at the very least,

there are loads more...

I can heavily...

Like, that men are much more likely to be musicians than women,

because they're more interested, because it's...

What means of...

Is that not true, Tom?

I...

My...

I don't know.

My...

What's the word?

Like anecdotal, my experience,

whatever, is not that there is a huge imbalance

between how many men become musicians

and how they adapt instruments as children and all that sort of stuff.

And it just feels much more of a cultural thing than...

I don't know.

I don't know.

Yeah, it could be a cultural thing.

I was going to...

To play devil's advocate, I would say,

aren't all the famous conductors...

Sorry, all the famous composers, not all men.

That's true.

But not all the famous performers,

when we're talking about performances here.

That's true.

But, well, back in the day,

Taylor Swift is a very famous composer.

That's true.

I'm sure I'd rate her up there with Beethoven.

I think perhaps you should be the great artist of our time.

She's obviously an incredibly gifted composer,

even if not to your tastes.

She knows exactly what she's doing.

And very musically skill, I don't know.

But I...

Yeah, the...

Not sure if she's up there with...

You're going to say it back.

But that's not really the point, is it?

The point is the numbers and the success rather than the...

No, you're right.

You're right.

I think, obviously, the whole thing's the same.

But the evolutionary stuff continues.

There's lots more of it.

Here's an amazing result from 2002, Tom.

Okay.

Married women who wore their wedding rings

had husbands with a lower, more masculine-ized 2D-40

than those women who did not.

This may indicate a higher commitment

to women to their union that...

What the fuck?

Isn't it great?

So the theory here is that

if your husband is more...

has more testosterone,

then you will be more committed

to your union with your husband.

Unless willing to signal that you're up for cheating

by...

Exactly.

You're there for...

You're wearing your wedding ring all the time.

And that is signaled

by your husband's 2D-40.

So I want to just think about the chain here, you know?

How...

Why would you expect...

Why would you expect to see...

This in N equals 79 people, right?

Think just think about like...

If you think...

If you just think mathematically about

just multiplying these effect sizes,

imagine these effect sizes do exist.

Surely they're not big effect sizes, right?

So you're going to have to multiply the effect size of...

Like, what is the effect size of

feeling committed to one's marriage and wearing a wedding ring?

I can't imagine it's like...

massively strong, but even...

You know, even if it's not super strong,

you then have to multiply that correlation

with the correlation of like...

The relation of male, you know...

Well, that commitment is...

The chain is right.

So the...

The commitment...

The women wearing them...

They're wedding rings when they are...

When they're not it and not up for it.

So what percentage of women don't want to...

So then...

Yeah, so that's the first...

That's the first variable.

Then...

And then you have to chain it back to like...

You know, what the relation...

Like, whatever men do,

behaviorally, that makes women more likely to...

Want to have that...

Have those feelings and be committed.

So that's another like...

Multiplication of a...

A fraction.

So the effect size is going to go down again.

And then...

What's the correlation between the man's...

Testosterone level and the way they behave?

So that's another multiplication of that fraction.

And then...

What's the relation between their 2D40 and their testosterone levels?

That's another fraction.

So like...

Do you...

Like, this must be the tiniest effect ever.

Just think about it.

It must be a tiniest effect.

Are you expecting to see this in 79 people?

Yeah.

Yeah, yeah, yeah.

Literally...

If one person happened to not turn up to the analysis that day,

it would be bigger than...

That would have more effect on the outcome

than I would expect the real effect to, yes.

I think that's a useful way of thinking, actually.

When you think about, theoretically, think about...

You know, if the effect size is 0.49,

you're going to multiply that by the next...

Chain of effect that you think is there, which is...

Even though it's like...

Even if it's 0.65 or something really big like that.

You're already at a tiny number, you know?

And you've got to multiply that again by another fraction.

Another fraction all the way through to...

Whatever you think this causal chain is.

It's not going to be a big effect overall, is it?

Yeah.

So you'd need tens of thousands of people to detect it if it was...

I would expect so.

Yeah.

This had P equals 0.03 in the...

Yep.

Paper.

And then...

Yeah.

And then in 2008, people tried to replicate it in a much bigger sample

and they tried every combination of, like,

women wearing the ring, men wearing the ring,

with their own 2D4D,

the digit ratio of the husbands of women who wore the ring,

and the...

Waves of men who wore the ring.

Like, they tried everything.

Okay.

They found absolutely nothing.

I mean, so there you go.

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It's been a fun little side project,

just stealing an hour every night again

to go and record in Works in Progress article.

And, yeah, I read it out in...

I think I've somewhat more...

Seriously.

So, a serious way.

Yes.

And then I talk on this podcast.

Do it more like an audio book.

So I'm excited about that.

Welcome to Works in Progress.

This is an article about the birthrate in Korea.

Like that sort of thing.

It's like, could up the final passengers

for BA like 3, 3, 4, 2?

I have tried to...

I've tried to inject some level of personality into it.

It's very good.

It's very good.

I've listened to some.

It's very good.

Well, thank you.

I'm glad to hear you say that.

So, yeah, if you want to hear me reading out works in progress articles,

you'll get one every single week from Works in Progress.

Where can they find that time?

I believe they can find it at worksinprogress.co, Stuart.

It's all the other articles and the podcasts and the newsletter

and all these sort of business.

So, do go on there and have a gander.

Absolutely.

And now, back to the show.

One of the correlations that is supposed to be reliable

is what you have mentioned before,

which is the correlation with homosexuality.

And the original finding in here is from 2000.

And some researchers went to a San Francisco street fair

and had 720 people measure their finger lengths,

report the sexuality, but interestingly,

this sparked the whole field off.

But actually, the only difference they found was for lesbians.

So, the difference between the 2D40...

So, lesbians had a more masculineized 2D40 than heterosexual women.

There was no difference for gay men versus heterosexual men.

Okay.

Okay.

It kind of sounds like...

Yeah.

Did they expect...

Was this pre-registered?

No.

So, the theory remains that lesbians are more masculineized women

and gay men are more feminized men and blah, blah.

Obviously, that garnered a fair amount of research

and actually just last year they put together a meta-analysis

on the many studies that have been done on this.

And basically, looking at the studies,

they claim overall that there is a result.

They actually claim that overall, as I just described,

men who are homosexual compared to men who are heterosexual

have a more feminized 2D40 ratio,

and women who are homosexual have a more masculineized one.

But, I mean, first of all,

I have to say that it looks like in particular for the men.

But, well, maybe for women too,

it kind of looks like these results are being driven by just a couple of studies

that are sort of quite far out.

Yeah.

Do you agree?

So, yeah.

So, there's a lot of studies where the conference intervals

comfortably cross zero and a few.

Which is fine for meta-analysis because you're putting together stuff

and you're getting poorer that you wouldn't otherwise have got.

Yeah.

No.

I mean, in the...

So, which of these?

So, the top left, that's the...

So, it's men and they're right-hand and left-hand.

Yeah, right-hand and left-hand.

Okay.

Okay, so, but it's very...

Yeah, it makes a huge difference.

So, okay, so the right-hand is the women,

and then there's not that much going on there,

but it seems as a couple of studies on it.

And then the left is the men,

and that feels like...

Yeah, there's a lot of...

There's a few studies that happen to be across,

but there is a...

I don't know.

It's just eyeballing it.

It could be something real, but...

It's fine.

It's fine.

Like, it's not...

It's not the most terrible looking mess analysis ever.

I'm not like bold over by it, but it's not the most terrible thing ever.

But wait, because there is more on this...

That casts a lot into that.

This is a pretty...

Overall, a pretty small effect, but it's there.

It's like...

It's something like point...

I could...

It could be...

It could be about point two or something.

So, that's...

You know, that's maybe the one that we've seen so far

that looks, at least at face value, the most realistic.

So, let's leave that there for a second.

From sexuality to sexual characteristics.

Obviously, you knew that someone was going to have written a paper

relating the 2D40 ratio to penis length.

Yes, of course.

Of course, they did.

Yes, yes.

And in this study, which came out in...

I think quite recently, I can't...

For some reason, I haven't written it down.

But yeah, flaccid and stretched penile length in the...

Oh, cranky.

So, is that the first time we've ever said flaccid on the show?

Do you think?

Probably not.

To be honest, probably not.

Yeah.

We did the circumcision episode really, we said it.

It was relevant to that one.

Maybe not, I don't know.

Who knows?

I'm not going to go back and listen.

Yeah, Carol.

The correlation here, they look at it in a univariate sense.

They just look at the basic correlation between the penis length

and the 2D40 ratio.

And then they also do a multivariate study where they kind of control

for height.

And for some reason, BMI for flaccid penile length.

I don't understand...

What they're thinking about, you would correlate...

Why you would control for different things?

Or...

I don't get it.

I don't know the world of whatever this is.

Proctology.

What do you call it?

It's not Proctology.

That's Bums.

That's how you're Earth.

You're all...

Eurology, I guess.

Yeah.

Yeah.

Or...

Yeah, I don't know.

I don't know.

It's something we should know, really, isn't it?

Let's go with Eurology for now.

Yeah, yeah, yeah.

So basically what they find is that...

Oh, digit ratio.

They have actually got a significant finding for...

They have here?

Well done, then.

They have.

Congratulation.

Even after you control for height and fourth digit length,

I don't know why you're controlling for that, but no,

there's nothing very.

There is a correlation between digit ratio and penis length.

So people with the more machinized digit ratio have a more...

Have a longer stretched, but not flaccid, penis length.

Fair enough.

Okay.

They grow as not showers.

Make of that...

Make of that what you will.

I haven't seen a replication or anything of that,

but...

Nor do I want to.

No, I don't think it's vital.

Let's face...

Yeah.

I'm always a bit anti-saying when we don't need to know about that, do we?

Because, you know, obviously these things are interesting and people...

Yes.

But this will be fairly low down my list of priorities for important research.

I agree.

I agree.

Okay.

So then, I feel like we should talk about what I would consider to be the...

...basically than the deer of this.

That's all exactly.

Or at least the sort of...

The point that it becomes so obvious to everyone that it's ridiculous.

Which is, do you remember those days in 2020 when scientists were...

Basically, they were twiddling their thumbs because a lot of their...

Twiddling my index and ring fingers.

Twiddling their...

Very good.

Thank you.

Never thought of that.

Very good.

Their grants had been cancelled.

Their classes had been cancelled.

They couldn't go into university.

They didn't have that much to do.

Obviously, everybody in the world was obsessed with...

For good.

COVID.

And when all you have is a hammer, etc. etc.

And I think this study from 2020 might be one of the most...

...when all you have is a hammer studies I've ever seen.

Which is...

People...

John Manning, the guy that came up with it originally.

Or, you know, most recently.

Did a study claiming that 2D40 ratio was linked to COVID fatalities.

Yes.

So when all you have is a 2D40 ratio database, then...

Yes.

When all you have is a finger nail.

Yes.

No.

Everything is a finger nail, I forget it.

Yeah. I'll get what you're going with it, though.

It's nice, though.

Yeah.

It was...

It was quite good a minute ago and I wanted to keep up with that about a fail.

You've done your best and that's what's important.

God loves that trial.

So they got the case fatality ratio as for various countries for COVID in April 2020.

And then they got data from this big BBC study from many, many years previously,

where they had got people to go out and self-measure their 2D40 ratio and report it.

And they got thousands of thousands of people to do that across many, many different countries.

And they were like, aha, we've got data for different countries for both COVID and 2D40.

So let's correlate them together.

Oh, God.

And here's what they've phoned up.

Okay.

The sample size for examining 2D40 relationships with percent of male deaths,

and equals 16, was small.

Yes, it was.

So it's 16 countries, right?

Oh, okay.

Yeah, okay.

So there's only 100 in something in countries in the world, right?

So they've done the best here.

Okay.

Yeah.

Just like you.

Nevertheless, they were positive correlations for males with both right and left.

I won't do this.

They're saying that they look quite big.

Chunky correlations.

Chunky correlations and significant,

I'll be it just about p-values.

Yes.

And a weak association for female right hands.

P equals 0.049.

So that's an extreme.

That's that's no correlation.

And just get out of here.

Come on, Matt.

Yeah.

But no correlation for female left hands.

Yeah.

I mean, again, yeah.

Come on.

Right.

Yeah.

Yeah.

And then this is the conclusion.

We speculate that male 2D40 is a negative correlate for expression of the SARS-CoV-2 receptor.

So they're saying it protects your testosterone levels make you tougher.

And you're not only longer fingers and also you can fight off the deadly man flu

that's killing the world.

That sort of thing.

Mental.

Yeah.

It is a bit less.

Unless it's all completely true and real.

And that's why.

Well, just think about this.

Like, well, the problems of this study were very

ably described by a colleague of John Manning.

So someone from Swansea University, which must have been very awkward

to criticize someone at your own university in print.

So this guy called Alex Jones, not that one, who wrote a really good paper

saying we're the turn of the freaking frog's game.

Turn of the freaking frog's fingers long.

He argued, I mean, first of all, this is the ecological fallacy, right?

He was taking data on some people and then correlating with data on completely

different people and saying, oh, well, there must be something at the individual level.

You're looking at things at the aggregate level.

Yeah.

And then saying at the individual level, it must be the same.

He points out that there's some inconsistencies in the numbers that they claim.

But the biggest thing, he points out, is that if you just got the fatality ratio

for the fatality rates, I should say, for COVID, for one month later.

So this would be May rather than April.

And remember, remember at the time, yeah, the COVID case data was constantly

being out there.

Successfully clicking all the time.

Like our world and data and things is madly.

Yeah.

Yeah.

Anyway, the correlation goes away completely.

Yeah.

If you just wait a month.

I will also say the date's wrong in the original paper.

But that's important.

I will also say, like, I thought that famously female immune systems

are better than male ones.

There was a lot of books that came out in around the same sort of time.

Actually, I reviewed it for the times.

Which I can't remember that.

I can't remember that.

It was an intensely annoying book.

But it was, it's, it's whole thing was women.

You know, how women, it was written by a guy and going about how women are souped

the superior sex because of various.

Oh, yes.

I remember that.

Oh, yeah.

I remember that.

I, I remember that.

I, I think I reviewed that somewhere else.

Yeah.

The better half by.

Oh, yeah.

Yeah.

Okay.

But by a guy called Sharon, Israeli.

So that's confused.

Yes.

Yes.

Yes.

Yes.

Yes.

Yes.

I remember that.

Yeah.

I reviewed that for something.

Definitely.

I can't remember.

Maybe not heard.

Yeah.

Anyway.

The point was that he was going on about how like, you know, women's immune system

and they live longer than us and all sort of stuff.

And, and it is, I think the fact the women's immune system is a better is the reason

my women tend to get vaccination scars and men don't.

And that is true in my, my children, because they have what they're.

I never heard that.

That's actually screw this.

I'm.

So.

So yeah.

So like, the idea that testosterone actually makes you better at fighting off.

Yes.

It just, it goes against my priors.

Let's put it that way.

You know, yeah.

Yeah.

So that, that I feel is the, where it really.

I mean, it may have jumped the shark at some of the previous examples I mentioned.

But if it, you know, if you didn't think it had jumped the shark.

It's definitely.

It's more to see over the shark at this exact moment.

Yes.

Yes.

Yes.

Exactly.

And I, I mean, I've hardly scratched the surface.

There's so much of this stuff until you've already.

It's because it's so easy to measure.

Well, we will come to that.

But like, it appears so easy to measure.

Like, it's just, it's such a good variable.

This shouldn't project.

You know, go off and give someone a questionnaire and measure their 2D 40 and you've got

yourself a study.

Yeah.

I haven't even mentioned the apartment correlation with athletic ability, which seems much more

plausible.

It seems quite variable.

The results in the study that I looked at.

It was quite an old study.

So I don't know where that is.

But like, if this is indeed a relation to testosterone, then it kind of makes sense, I guess.

Yeah.

Athletic ability will be related to it.

We will come to something about that later though.

And then what about the study where they tried to look at cave paintings, where people

had prehistoric cavemen had drawn around their hands.

Oh, it's brilliant.

It's drawn around their hands.

And then they were like, shit, we can tell whether they are as a male or female by looking

at a 2D 40 ratio.

I'm sure it would be easier to tell whether they're male or female, but like, truly the

solid is a bit better.

Exactly.

Exactly.

Yeah.

Exactly.

Yeah.

I think even John Manning was a bit skeptical of that.

That's exactly so.

As far as I can tell, basically for everything that has been claimed, either it's in a tiny

sample, has a tiny effect, looks a bit sauce in some way, doesn't have enough replications

or like has replications and they failed.

I think there are a couple of exceptions to that.

I think maybe, again, it feels like you have to look at the sexuality thing, potentially,

and potentially the athletic thing.

Okay.

But we will come to some reasons to doubt even those in just a moment.

But I did just want to throw in this BMJ Christmas issue paper, which obviously, you know, every

year they do the Christmas issue and it's kind of got fun papers in it.

Yeah.

Which is sort of a joke, but sort of not sort of thing like this.

Yeah.

It makes you laugh, but they make you think.

Exactly.

They could win.

They could win the Ig Nobel Prize.

Exactly.

So here's a, this is from the 2021 issue, and they correlated 2D 40 with, well, I'll let

you read it.

Okay.

Results.

2D 40 significantly correlated with select body composition parameters, we'll read the

details here.

But the correlations varied by sex, participant hand measured, and the method of measuring

2D 40 by photocopy or radiography.

However, the strongest correlations of was between right hand 2D 40 and men and poker

hand rank.

Good nice.

That is nice.

That was interesting.

Correlation of 0.28 p equals 0.004 with poker hand rank, which, so just to, to, I

make the joke clear here, that's random, right?

Yes.

Yes.

Oh, God.

I thought I was going to say, I thought, I misread that assuming that meant that you were

good at poker.

No.

No, just what, what, you happen to get?

It's what you get from the shuffled cards, right?

Yes.

So, yeah.

And then the conclusion.

Greater prenatal exposure to testosterone, as estimated by a lower 2D 40 significantly

increases good luck in adulthood, and also modulates body composition.

I'll be at 2 less to the grade, that's it.

That's brilliant.

Very funny.

Funny that the correlation, I mean, just they, they themselves got quite lucky here for,

you know, to tactic purposes.

Did they, or did they just do it all the time?

Did they hack it?

Yeah.

The point is that the correlation with a random luck variable was like around about the

same, maybe a bit higher than the correlations with actual measurable characteristics.

Tom, just, you can just read out the summary here.

Okay.

When interpreted in the context of the 2D 40 lecture, this finding provides further evidence

that 2D 40 might be a universal biomarker of one's fate.

In reality, our statistically significant results are actually serious, and raise the

possibility that other claims regarding 2D 40's association with human health and behaviour

might also be false positive findings, only to weak experimental statistical methodology.

You think?

Yes.

Yes.

I thought that was quite a fun, quite a fun little illustration.

Yes.

But it actually gets worse than this, because I think there are two, you know, even if

you accept all of the above correlations might have something going on, which, you know,

maybe not.

There are two massive problems with the 2D 40 idea, one of which is about measurement.

So remember that 1888 paper that you read the quotes from earlier?

Yes.

This is the same paragraph you wrote, they wrote very long paragraphs back then.

This is the continuation of the same paragraph that you read earlier.

I have myself made a considerable number of examinations of hands for the same purpose,

and find that the matter is more difficult of solution than would at first appear.

If the fingers are not held firmly in a definitely chosen position, I think the results obtained

very questionable, for a slight abduction or adduction of the hand causes the relative

length to vary considerably.

I feel like I'm reading something from Bram Stoke's Dracula, it's the exact same thing

in language.

Yes.

In 85 individuals examined, I found the stake with which I plunged into the vampires'

heart.

Sorry, yes.

In 85 individuals examined, I found the indexed equal or exceed the annularis in 9 cases.

There was no perceptible difference in the two sexes, but Auna and Fisher have recently

shown that conclusions drawn from the living hand are not correct, as the measurement cannot

be accurately made from the axis of motion of the joints.

The examined 40 skeletal hands and found that in no case did the index equal or exceed

the medius in length.

When the metacarpal bone of each finger is counted as part of the index, the index is invariably

longer.

OK.

So by the way, I looked up a Dracula came out late years after that.

Yes.

Very close.

I don't say, OK, just before I let you make the point that you're going to make, which

is the obvious one, this is all, but when you asked me at the beginning, and I held my

fake hand in one position, the index was indeed longer than that, but I only had to tilt them

very slightly to the left to a still quite natural position, which I could, so that's why

I'm pleased I didn't know which was the right answer beforehand, because then I could

easily just looked a little bit and now it all looked like my ring finger is now longer.

So given that this has been a problem that we've known about for over 130 years, you'd

think maybe we'd have found some decent way to solve it, right?

But unfortunately, basically, it turns out that the way you measure the digit ratio can

affect the results, as you were just saying a minute ago.

And looking at them is one thing that, you know, sort of doing a self-report, but like

people have looked at all different ways of, you know, once you're taking the, taking

a picture of it is one thing, like how do you do that?

Do you put your hand in a photocopier?

That's a very common one.

Do you take a photo and then analyze it with a computer?

Do you measure it?

Do you, just like another person, like a different person come in and like put calipers

on your fingers and measure how long each digit is?

And like, where do you start the caliper there?

And if they move, how does that differ?

If you put your finger on the, if you put your fingers on the photocopier, do you put

slightly more pressure on the left or the right side of your hand as you, as you hold

it down?

Like, how do we standardize this?

What you'll say is degrees of freedom, is the problem.

Massive degrees of freedom.

There's a paper in 2009 that looked at this explicitly and sort of just like got people

to measure it lots of different ways.

And then tested whether, first of all, the, they would get the same measurement again

if they themselves went and did it again, Intra Observer Reliability.

And then whether other people would get the same measure, Inter Observer Reliability.

And in terms of that, there's like, you know, at the time there was a computer-assisted

way of like analyzing the pictures, as like analyzing photos.

And with that, you get the highest reliability.

So both, both for within people and between people, 0.957 and 0.892.

And photocopies are still pretty good.

Physical measurements are like not so good for Inter Observer Reliability, but decent

for Intra Observer Reliability.

So that means that like different people will measure things slightly differently and

you're not going to get perfect agreement, printed scans or the worst.

I'm not exactly sure, you know, what constitutes a printed scan versus a, you know, a photocopy.

The point is that the way you measure this is going to make a big difference to the

results that you get.

And that's, that means that it isn't biology being measured, you know, it's like, it's,

it's, it's something to do with human psychology or human error that's being, that's

being measured.

And they recommend that you use, you know, this computer-assisted technique.

I assume these days you can do it better than they could do in 2009 in computer-assisted

techniques.

And they, they say that the, you know, I actually manning himself was written about this

as well.

One thing that I found striking, if you look at the details of, like, if you look at that

sexual orientation metanalysis, you only find the results they find that is the sort of

the pattern of feminized versus masculized digit ratios in gay and lesbian participants.

Only find that if you look at the photocopy method and there's no results at all if you

look at direct measurement, like caliper measurement or self-report.

Yeah.

There's nothing at all there.

It just says it's not real, it says to me, it's not real.

Yeah.

Yeah.

Yeah.

They say that they have this sort of weird discussion section where they're like, oh,

maybe the people with calipers in some of the studies, they sort of knew what the study

hypothesis was and they might have changed the results.

And actually, I think that's, that's quite plausible.

Like, if you've got somebody measuring something that is actually quite fiddly and hard to measure

and you're pushing up against people's, like, soft tissue as well as they're bone and

where do you actually put the caliper and stuff?

And so I can sort of imagine that there could be unconscious biases there, but I don't

think they make a big enough deal of it in the text that, like, there isn't a result

if you look at it.

If you slightly change the measurement system, yeah.

Yeah.

And by the way, in that big BBC study, the one that they used in the COVID thing, and

also they used that BBC study for a whole bunch of other, you know, bits of peer-reviewed

research too.

That was just people sending in their own measures.

Like, how, like, come on, how do you expect?

Yeah, I mean, presumably the errors would, like, well, I don't know, will the error, I

suppose, here's, here's another problem, right?

Everyone or most people are large percentage of people know that you want the fingers,

what do you want the race in one way?

So like, do everyone's getting one, will you, will that affect, you know, if you measure

it in your fingers one way, will that affect what you sent it in?

Will it affect whether you slightly tilt your fingers to the left or right?

Exactly.

Exactly.

You know, so it's just, I mean, it's just after this point, you'd have to have totally

naive participants who, you know, like, like you at the start, like you didn't know which

way it was supposed to be, or you couldn't remember, you've probably, I'm sorry, I've definitely

heard of it.

But I'd always vaguely assume that you wanted the longer index finger, because I was always

like, oh, I've got slightly longer index finger index finger index finger index finger index.

No, no, we're both the, we're both the wrong way, don't we?

We're wimpy, wimpy little girly men.

Yeah, exactly, exactly.

So this is going to introduce loads of noise into the studies, which are noisy enough

to begin with.

Yeah.

Like, there's another issue, which is the issue of correction for hand size.

Now, remember, we talked about this in sex differences in brain size and like, should

you correct for the overall body size or not, and there was a whole discussion there,

that was ages ago, we did a podcast on, on that, but there's been debate about what they

call, um, alarmetric scaling in this, which is the idea that as hands get bigger, they,

the ratio between the fingers is not one.

So like, if you just make the hand bigger, the ratio would change.

Okay.

So it wouldn't just become like a completely, a complete facsimile of itself, but bigger,

but it would, it would actually, the ratio of the fingers would, would change.

The alarmetric exponent is not one, they say, between, between the, uh, the, the two

details.

Sort of, as your hands grow bigger, the hat, you'll, your, you will expect one finger

to grow faster than the other.

I assume, because also your finger is not just a finger, it's also attached to bones

within the hand, which are growing presumably and have their own function.

Yeah.

Right.

Right.

And there's all sorts of like hawks gene action going on there about like how the body's

plan is supposed to be going out and that gets influenced by hormones and so on as you,

as you grow.

So like, anyway, the point is that as you, you'd expect people with bigger hands, that

is men, would have a different 2D 40 to people with smaller hands, that is women, even

if these particular, you know, testosterone things were, or, or like, you'd expect that

to happen anyway without even holding testosterone constant, I think is the argument in this, in

this paper.

Okay.

There's pushback on that though from another paper in 2021, let's say that the scaling

is, you know, it's still relevant, but it's not fully, it doesn't fully negate the 2D

40 ratio because even if you do correct overall for, um, for sex, you still find, uh, differences.

So I, I, I haven't dug into this in extreme detail, but the point is there is debate over

like exactly how this is measured.

There's also debate over the, just the mathematical status of using a ratio in some of these, um,

statistical analyses and, you know, normally you're, you're using numbers that you've measured,

you're not using a ratio between two things and that has different mathematical properties,

uh, which maybe make the numbers less reliable as well.

So there's all sorts of issues there.

Yeah.

The whole, just, at this point, you just listed so many, like, uh, you'd have to do something

incredibly careful and to, uh, I don't know, to the extent that I've done the annual,

I will never do this study that makes, that makes me believe it because you'd have to

have multi, multi thousands carefully measured individually and no one's going to do that.

It's not that important.

Um, yeah.

Well, exactly.

I mean, people have claimed it's important.

Like people have talked about this as like, oh, this is a great, you know, a measure

of whether someone's going to be aggressive and so we can use it in criminological.

Yeah, but that's obviously shit, isn't it?

Skept, well, yeah, it might be, it might be a very, very minor effect at the margins,

which would be interesting to know about.

It's never going to be like, well, look at this guy's got a slightly longer ring finger.

Therefore, put him in charge of the, uh, you know, the big accounts down, down at the

trading floor, you know, or he's going to go and murder everyone.

It's not going to be like, it's not going to, you know, indeed, that is not how the world

works.

Um, and then the final point, by the way, is that there's two hands.

So if you add the fact that you have males and females right in left hands, multiple different

ways to measure this correction for overall size or not correction for overall size.

And then all the other statistical degrees of reading that you can have within a study

about the individual participants and so on.

It's a lot of forking paths.

Yeah.

A lot of ways that you can do the analysis that find the results that you want.

And so I basically don't believe any of the things we've talked about, even the ones

that look more plausible.

Yeah.

I'm less surprised if the sexuality one came true and you didn't show me the faintest

bit of evidence other than you said it, but for the sports one.

But again, that doesn't sound quite so mad in its own right, you know, yeah.

There's a, I mean, here's, but then I haven't even got to massive problem number two yet,

which is, does 2D 40 even relate to testosterone?

Like, we have other ways of measuring testosterone.

Does it, does it correlate with them?

Oh, God.

It seems like you should start, you should start by doing that, right?

Turns out we have a meta analysis published in 2024.

I don't know, I don't think meta analysis are the best thing in the whole world or anything.

But I think that if you have something that you consider to be a proxy,

that it should have at least, you know,

chunky correlations of relationship with other measures of that same thing

that isn't meant to be a proxy for, right?

Yeah.

I think that seems like a bit of a, like a, the minimal bar to clear, yes, I agree.

Yeah. So in this, they looked at various different studies, I think 54 studies,

8,000 participants, measures of circulating testosterone,

like when someone is an adult, testosterone change over time,

prenatal testosterone measures.

And here's what they found on, we found no evidence of the relationship

between the above testosterone types and digit ratios.

Furthermore, there was no relationship between testosterone and the right and left 2D 40,

male and female 2D 40 and the 2D 40 and testosterone measurement,

I measured in blood and saliva, blood or saliva.

In summary, considering the current state of knowledge,

any conclusions drawn from the assumption of the digit ratios

as the proxy for testosterone, prenatal adult level,

or testosterone change under a challenging situation,

warrant great caution.

Hmm. Oh, yes.

Yeah. So, I mean, to some extent, they could,

they could say, we don't care about socioeconomic testosterone,

we don't care about testosterone change,

because we're only talking about this prenatal effect,

but it's got prenatal testosterone as well,

and that's just bugging that.

Yeah. Yeah. Yeah.

It all sort of false to bits.

Oh, yeah. That is, that is a right kick in the balls, isn't that one?

Yeah. And the thing is, right, you'd expect prenatal testosterone,

I assume, I don't know, testosterone expert,

but you'd expect prenatal testosterone.

You can say that against you, I'm sorry.

To be, yeah, yes, yes.

Well, you've seen my thing.

And you've seen mine, so, yes, yeah.

It did. And I think you'd expect,

if any of these behavioral effects were real,

you'd expect there to be some testosterone differences,

like circulating as adults as well, I think, I think that would be fair to say.

I suppose, yes. Like the point is, also,

this is supposed to let us show how that we are all,

that people with the correct sort of fingers are more manly in some other way.

So, if you're then, if you then have

low testosterone later in life,

and testosterone has any of the big effects that people seem to think it does

beyond just making you grow in different ways,

then yet, then that seems unusual.

That seems surprising, yes.

I would be, yeah.

And I should say, just as a final point,

there's also been genome-wide association studies where they have put 2D-4D in

as like, you know, to see what genetic variants are related to it.

And they didn't find that it, they could have found that it was related to,

like, Androgen receptor related genes, but it wasn't.

Now, that's quite preliminary. Maybe in the future, they'll find that.

But like, testosterone didn't jump out.

Testosterone related genes didn't jump out as related to 2D-4D

in the GWAS that has been done, genome-wide association study that has been done.

So, I don't think that's like super clenching evidence for anything.

But like, there's one more question.

That's an opportunity for it to, yeah.

There's an opportunity for a little bit of biology to line up there, and it didn't.

So, Christ.

So, I think this is a great example of a whole

line of research with thousands of studies, and presumably a bit of money.

I mean, I guess the point of this measure is that it's cheap.

But like, certainly a lot of people's attention,

but resources too, and people's time, and effort, and so on.

Going into something that I just don't think ever had any

likelihood of being real.

I think.

And, yeah.

Sorry, Karen, you finished it.

You finished your miserable sad depression.

Well, no, that's it.

I'll finish my one with you.

No, you don't, you go.

No, mine was like, we normally we come to these things.

So, only though we can't, it's quite hard to say, isn't it?

Like, probably, these studies are pretty bad, but like,

then, you can't just completely throw away people's experiences,

and maybe we should be a bit more, you know?

It just sounds like bullshit from top to bottom.

There's proper.

Absolutely.

A bit calmer.

And I should say that I did a, I did a, you know,

when you do a Google search for 2D4D studies in 2026,

there have been, I mean, it's early March, as we recorded this.

There have been 125 studies already this year.

Published on 2D4D ratio.

And you see in other studies, there's a 2026 meta-analysis

on the relation between testosterone and risk aversion.

Like, again, an interesting question to ask.

And one of the measures of testosterone that they use

is the 2D4D ratio.

So, it's in, like, they use it in, you know, meta-analysis

of the broader question.

And they do mention the issues, you know,

as my friend Ruben Arsland pointed out, like,

why even use it if you think it's a crap measure?

Like, they do get the same that no result from other

more direct measures of testosterone.

But why even include 2D4D, you know?

Just, it's just not real.

It's just not real, right?

I think it may just not be real.

And I think that goes to show something quite.

Yeah, I mean, I like that you saved that bit at the end,

like, for the, it doesn't actually correlate with testosterone

this entire thing.

I can't find the evidence of the correlation.

With other, other measures of testosterone, either, yeah.

Absolutely mental.

All right, okay.

Well, yeah, that's, that's, that's, I'm so good about my fingers again.

My fingers don't worry me.

Yes.

Yeah, yeah, I'm not concerned that I have weak soy fingers.

I, it's just another cautionary tale about whole scientific fields.

And this one is, like, very obviously, you know,

gone on, on the wrong direction.

But the question you have to ask is, like,

how many other entire scientific fields are chasing

complete phantom measures like this?

Yeah, so, well, I hope you've enjoyed another episode of The Nileism Show.

Yeah, I'm afraid that's it, but hopefully a more fun one

than the previous episodes on, well, literally depression.

So, yeah, there you go, Tom.

That's it.

Thanks for your time.

See you next week.

Take care.

Cheers guys.

Bye-bye.

Bye-bye.