Science, sex, and your hands

Here's an interesting fact about sexual dimorphism: On average, if you were born a male, your hands are a little bit different from those of someone who was born a female. Most men have a pointer finger that is a little bit shorter than their ring finger. Most women have a pointer finger that's about the same length as their ring finger, if not a little longer.

People have noted this differences between the sexes for centuries. But what's it mean? Truth is, we really aren't sure yet. But it is correlated to a lot of awfully interesting things. In fact, some scientists think "the finger thing" (as I like to call it) is a hallmark of prenatal hormone exposure. Because of that, in the scientific literature, you'll find lots of examples of studies that try to find a connection between the finger thing and seemingly disparate traits, such as sexual orientation and gender expression.

We talked about the finger thing on a recent episode of the Sex is Fun podcast—what it's all about, what fingers could be telling us about people, and why it's maybe all just a bunch of hooey. Take a listen!

Also, for the record: My right hand has lady fingers. My left hand does not. How about you?

Sex is Fun

Image: Hand, a Creative Commons Attribution Share-Alike (2.0) image from teleyinex's photostream

Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.

Maggie goes places and talks to people. Find out where she'll be speaking next.

MORE: correlation • gender • Science • Sex • sex is fun • sexuality

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blueelm

Both of my hands are “male” looking. I have man hands. Great, I’ll add that to my list of things I’m depressed about tonight.

I do wonder what that means though for us man-handed women. Then again, it also kind of sounds like a load of garbage too.
sean

Phew! I’m normal! So it doesn’t sound like a load of garbage to me!
pjcamp

The ladies like my fingers. One of them anyway. Does that count?
- blueelm
  
  Just one lady or just one finger? C’mon ;)
http://twitter.com/tardiskitten thisbikeisatardis

ooh! I have man-hands! this explains why I’m such a failure at being a heteronormative female! YAY!!
- http://www.facebook.com/profile.php?id=30003282 Houston Lang
  
  No, it’s because you’re an individual, capable of choosing your own destiny based on preferences and predilections both within and beyond your control.
  
  Heteronormative is an atrocious word; please stop molesting my language.
  - http://twitter.com/stevepan1 Steve Pan
    
    Thanks for sharing asshole
  - marilove
    
    Your language? Really?
    
    LOL
    
    Get over yourself.
  - Maria Pranzo
    
    Pillar — me too. Man hands. Tiny little man hands.
    
    And it’s my language, too, so please feel free to use heteronormative on my side of the yard. We have cake. And lemonade served in heteronormative pink and blue cups.
    - http://twitter.com/JohnThomasWeb John Thomas
      
      Can I have some cake and lemonade?
http://theladyfingers.blogspot.com/ Ladyfingers

Ladyfingers has manhands.
Donald Petersen

Maggie, it seems our sinister hands were swapped at birth. I’d trade you back, but it would seem the damage has already been done.

Plus, I don’t think the hairy knuckles would suit you.
http://twitter.com/WillieIJ willie imara johnson

I have man hands :( my pointer is way shorter than my ring finger. F@*k your science I’m still a lady
BombBlastLightingWaltz

Hello My name is Mrs. Harry Palms. How can I help you? waka waka
Gabriel Meister

“Lady fingers” always reminds me of the last line of the Stephen King story, “Survivor Type” [http://en.wikipedia.org/wiki/Survivor_Type], which I read when I was about 10 years old: “lady fingers they taste like lady fingers” … ugh. Thanks.
- dioptase
  
  You beat me to it. When I quote that line, only my brother knows what I’m talking about.
http://twitter.com/wjcstp Bill Connell

Huh, I’m a dude with huge ladyhands, apparently. Ladies.
- http://celesteagnes.blogspot.com/ Sekino
  
  ’Huge Ladyhands’… Could be a pretty good band name.
  - http://www.facebook.com/profile.php?id=30003282 Houston Lang
    
    Hugh Djladyhands could be a very successful niche pornstar name.
http://www.facebook.com/people/Linley-Lee/665497022 Linley Lee

I have one of each
http://profiles.google.com/mkjonese Emma Jones

My dad pointed this out to me when I was a teenager, actually. I like my man hands.
- snackar
  
  I too like my manhands. But I am a lesbian, so I guess the story lives on to see another day.
lukee

Maggie, can you / BoingBoing arrange a super-unscientific and anonymous internet survey asking:
1. Finger length ratios (right and left)
2. Kinsey scale
3. Handedness
?
- Snig
  
  4. Profit!
danimagoo

I have ladyfingers. I was, however, born male. I had already made the decision to transition to female when I first read about the finger thing. I checked out my brother’s and father’s hands. They both have typical man hands. Doesn’t prove anything, but I always found it interesting.
- http://twitter.com/NireBryce Nire
  
  Theres always the simple trans metatest: “if you’re testing things to see if you’re trans, you’re probably trans”. And yeah, I was that way too at the start.
  - http://fallsastar.com Crashproof
    
    For the widest umbrella definition of trans, sure.
    
    I did these tests quite a lot to see if I was trans, and decided I am a happy nonbinary gender mutant. Trans is a label I’ll accept but not necessarily claim, if that makes sense.
    
    I do have man hands. Mildly disappointed I don’t have one of each. Tentacles would be better though.
    - tyrsalvia
      
      I wish there was a trans something where you would get tentacles. That’s a transition I might go for.
snailspace

I’m a lady with manhands. My (male) partner has ladyhands. Guess that’s why we complement each other so well.
tubacat

I have man-hands, and I’m also left-handed and love math. I’m female but always felt a bit different (never “girly”). Bisexual, as it happens. So I tend to think there’s something to it…

By the way, there’s a great “quiz” about sex, gender and the brain by the BBC. They used it to collect data many years ago – the study is over, but the quiz is still up, and will give you a “masculine/feminine” ratio-type score, if I remember correctly. It’s at:

http://www.bbc.co.uk/science/humanbody/sex/add_user.shtml
- CH
  
  Hmm… I’m female and both of my hands are “man-hands” (I have short fingers overall, though), and I have the same that I never felt “girly”, always thought boys had more fun and that girls really got screwed in the “having fun” department by society, so I really wanted to rather be a boy. Well, until I learned to “screw that” what comes to society’s expectations and just be myself, so I’m now more than happy in my own role as a female.
  
  I’m definitely hetero… but perhaps more in the sence that I don’t really like “traditional” women that much, we don’t really tend to get along. I’m way too direct, I _really_ don’t like the dancing around one needs to do… I’m more of a “one of the guys”. But dunno if it is the hands, or just growing up around a lot of guys… my own guess is a bit of both. Anyway… my mom had gestational diabetes with me, which I think would raise the testosterone level in the uterus, and it does raise the testosterone levels for the girls, which I do have (raised testosterone levels, I mean).
- IronEdithKidd
  
  Great. Now the BBC thinks I’m a man.
crash2parties

Apparently, the phenomenon has a high enough correlation that they used it to ‘sex’ prehistoric cave ‘paintings’ (the ones that spattered pigment around the artist’s hand) & was known back in 2009:

http://news.nationalgeographic.com/news/2009/06/photogalleries/cave-handprints-actually-women-missions-pictures/photo2.html

http://www.dailymail.co.uk/sciencetech/article-1197680/After-25-000-years-scientists-discover-artwork-created-cave-men-AND-cave-women.html

Published in a journal in 2010:
http://www.cse.psu.edu/~ge/publications/mm10.pdf
bjimba

I’m glad to see I’m not the only manohermaphroditic person here. I’m male, with a female left hand and a male right hand. (And for the record, I’m left-handed.)
- ocker3
  
  I’m male, right-handed, with a male right and female left hand. I wonder if BB’s readers (or commentors?) are other than average compared to the wider population in this matter? Or perhaps those of us who Don’t fit into the average are more inclined to comment on this post :)
  - penguinchris
    
    I certainly think it’s more likely that those who don’t fit are more likely to post.
    
    I’m male and have ladyfingers apparently, though while on the right the pointer is significantly longer than the ring finger on the left they’re matched in length. I write right-handed but have mixed dexterity for other things (some things I’m right handed, some left). And I’m not gay but I’m far from any Kinsey-scale extremes.
  - Ipo
    
    True, I wasn’t going to comment either, being stereotypical and all.
    But I fit the pattern being a totally straight manly man.
    I have a relatively low inhibition threshold for using physical violence.
    I avoid it with conscious effort. Now.
    I have a high ratio of ring finger length to index finger length.
bobarctor

Think she deliberately didn’t mention this one until after all the ladyhands posted up?
(disclosure-ladyhands here)
http://www.nature.com/aja/journal/v13/n5/full/aja201175a.html
- Antinous / Moderator
  
  And all this time, I thought I was being ring-checked.
- Donald Petersen
  
  Danged if I’m gonna pay $32 to read the rest of the story. Are they saying that long index fingers mean short weiners?
http://disqus.com/Kimmoth/ Kimmo

Also, for the record: My right hand has lady fingers. My left hand does not. How about you?

Vice versa; left index slightly longer, right index noticeably shorter.

If I had to guess, I’d rate my testosteroneage about 65-75% along a typical range, based on all the resulting traits. My fingers alone would prolly have you guess 50% or so.
atimoshenko

Huh, I have a woman’s hands, apparently. Go figure.
Beanolini

How is one supposed to measure this? Mine are apparently close enough that I appear to have ‘lady hands’ if I look at the palm of my hand, and ‘man hands’ if I look at the back.
- Ipo
  
  Tendons doing their thing.
  I can reproduce that effect, to a degree.
  Measure putting the hand straight-wristed onto a surface.
  Palm down.
- Architexas
  
  In theory (and in practice) you should measure your fingers from the center of the crease where your finger joins your palm. It’s easier to tell right off the bat if you do it in metric.
http://yanminhong.blogspot.com Yan Min

Right hand pointer wins, left hand ring finger wins. I call that a wash.
AttackHamster

The typical variation in finger length ratios between individual people swamps the mean difference between males and females. Use of finger length ratio as an indicator of sex/sexual orientation/banana size etc. is an unscientific crock:

http://freethoughtblogs.com/pharyngula/2012/03/08/digit-length-ratios-and-overinterpreting-the-data/
Textuality

Well well well… I have girlie hands, and my missus has man hands. I wonder what that means? :D
http://twitter.com/SIxGablesBags SIxGablesBags

hetero mother of 3 with a serious case of manhands. And I’ve never been one to male-identify, even though I’m not a sparkly princess, either. Also, right handed.
TheMudshark

I used to be insecure about my relatively small hands. No more – the index-to-ring-ratio is ultra manly. *Home Improvement grunt*
http://www.facebook.com/profile.php?id=1582197685 John Qualmann

I’m exactly the same as Maggie, except am male. Right hand lady, left hand man.
Camp Freddie

I always find this sort of thing a bit odd, since the relative lenth of your fingers is very hard to measure. If you move your finger tips left or right by a very small amount, then the other finger will appear longer. I suspect that much of the apparent difference is due to how the muscle tendons develop, affecting the natural resting position of your fingers, rather than actual ‘finger length’. Plus the bias you may have towards making one finger look longer.

Nevertheless, it appears that if I try to keep my fingers in a ‘natural’ position, I am much like Edmund Blackadder:
http://www.youtube.com/watch?v=_EfW9znJYjw
DeS11

Wow. 30 years I’ve gone not knowing my left fingers were slightly different than my right. Wtf have I done with my life?!
awjt

I know someone who had polydactyly as an infant. They surgically removed the 6th digits from hands and feet, the “extra pinkies.” I am told they were fully functional. Now she refuses to play Rachmaninoff, in honor of her stolen digits.
- Donald Petersen
  
  Man, oh, man. What a quandary! I don’t know what I’d do if I had a child born with extra functioning digits. My strong initial reaction would be to just leave them as they are. Normalcy isn’t always an improvement.
l337n00b

When I first heard about this about ten years ago it was because someone had just done the study showing the correlation between “man hands” and homosexuality (in both sexes, longer ring fingers than average for your sex is correlated with homosexuality). One of the people who did the study said, “This is not a test to see if your friends are gay.”

I thought, “Then what is it for?!?” Having no other possible worthwhile application, it seems like jokingly questioning your friends’ established sexualities is really the way to go with this. Of course my own hands are just completely abnormal, with significantly longer pointer fingers than ring fingers. It remains an open question as to whether when you go down through heterosexuality you become more straight or wrap around and end up gay (any evidence from my own personal experience being merely anecdotal).
- Tess
  
  Well, I already look at a woman’s hands to see if she might be gay, although I’m not looking for long ring fingers. I’m looking for one thing anyone who thinks someone’s cute might look for (a wedding/engagement ring). Also for a plain silver ring or a piece of pride jewelry… but mostly I look at her fingernails.
  
  Hey, more clues are better.
Suburbancowboy

How are we measuring this? If I look at my hands, my pointer finger looks longer than my ring finger (meaning the distance from my wrist to the tip of that finger looks longer. HOwever, when I actually measure my finger (marked it on a piece of paper) my ring finger and pointer finger are virtually the same length.
http://www.facebook.com/profile.php?id=8834925 Chauncey Scott

Ma-ma-manhands.
retepslluerb

People still use hands? How quaint.
aprilsaur

Man hands here. But I always knew I was a TRUCKASAURUS
timmaguire

I have lady-hands. Which I’ve never found to be a problem except that I have lady hands.
Guest

I would predict that a greater than average proportion of the ladies of boing boing have man hands. And that the converse is equally true. Seconding the request for an informal poll.
Architexas

I’m a (hetero) gal with a right lady hand, and a left man hand. I wonder if my predilection for short hair comes into this somehow?

Nah.
DevinC

My right hand is significantly more masculine than my right.

I wonder if there’s any correlation between the manliness of my hand and how often it, rather than its partner, is used for a certain, er, activity.
- awjt
  
  Sure, it’s called contact biology.
- Donald Petersen
  
  Is its palm hairier, too?
Brewer_ME

Severe manhands on this left-handed lady… but I always knew I was a bit wishy washy.
for_SCIENCE

So, by this measure, I have very feminine hands (smallish, index fingers ~8mm longer than ring fingers), but am a hetero male. Must be an outlier…
http://twitter.com/JohnThomasWeb John Thomas

The Sex is Fun Podcast sounds fun!
jerwin

So, about how much shorter should the pointer finger be? Are we talking “sixteenth of an inch”, or “three thirty seconds of an inch” or what? Please. I need to know. It’s important for my masculine identity.
http://www.jeremiahblatz.com/ Jeremiah Blatz

So, yeah, I’m a male, but my pointer fingers are both longer than my ring fingers. Like, several millimeters. Also, I am a “hard gainer,” I have much more lower body strength than upper body, and find bro culture repugnant. While I keep being told that the plural of anecdote is not data, that’s kind of hard to see from the inside of this correlation line.
Mike Schell

I discussed this issue once with a person doing research on this topic. He insisted that the correlation is only valid for the right hand–even in left-handed people. For the record, I’m hetero male, with a male right and girly left.
Tess

Kinsey-6 lesbian with markedly longer ring fingers. I find it reasonable that hormones in utero could have something to do with sexual orientation, personally.