Women; they miss nothing, and here’s why

It’s distinctly uncomfortable for us men, but some women are, biologically, much more equal than we are. Of course, women can do all sorts of things that we can’t, like having babies, but this is far worse.
They have better colour perception. Well, perhaps 20-50% of them do. And they can use it against us, well against some of us. And around 5% of them are really super in this.
Now, I’m sure that you recall that we have three ‘colour’ receptors in the eye, sensitive to red, green and blue light. The sensitivity of the ‘green’ cones extends, weakly, into the red and the blue; this is also true for the other receptors, there is an overlap of sensitivities. We also have ‘rods’ sensitive to light, brightness and darkness. Cows don’t have colour perception, so they can’t see that they are eating clover or ragwort; and the red rag that the matador waves is just movement to the bull. The colour doesn’t matter (rather like the snake and the snake-charmer; it’s not the music of the flute, it’s the movement that gets them.) Even more strangely, some people have degenerative diseases when their rods, light/dark sensitive, and their cones, for ‘colour’ vision are destroyed, yet then can still distinguish between light and dark: there seems to be a third receptor (so far unidentified) for light.
The genes for the red and green cones are on the X chromosome. (The genes for blue cones are on chromosome 7.) The X and Y chromosomes are what make us male or female; two Xs and we are female, an X and a Y and we are male. It’s rather discomforting, for a man, to realise that the default* human embryo is a female, and that it takes the miserable, shrivelled up, runty Y to turn it into a male.
So, a male is genetically XY and a female is XX. If the X is defective, the man can be ‘colour-blind’, having the inability to easily distinguish between red and green; around 8% of men are colour blind. (Women can also have red-green colour blindness—from a colour-blind father and a mother who is a ‘carrier’, but this is much less common, at perhaps 0.5%.) If you have a high-end computer monitor you can ’see’ what a colour bind person will see; vital if you are a webmaster.
Now, it was always accepted that if we had two copies of chromosome, the genes on one of them would be ‘turned off’; so for the normal female with XX, one of the X’s was ‘non functional’. But this isn’t correct. It’s now apparent that both genes can be at work. So, the XX female can have parts of each chromosome ‘on’. In perhaps 20-50% of women, this means that they get two slightly different (usually, as far as I can determine, green) receptor cones in the eye. In a much smaller number of women, perhaps 5%, they can have two green and two red receptors; they have ‘5-colour’ vision.
As the blue receptors aren’t on the X, but doubled on chromosome 7, do we all have the possibility of two blue receptors? If this exists, I haven’t found any reference to it so far.
What, practically, does this mean? The ‘green cones’ on the two X chromosomes may be most sensitive to slightly different wavelengths of light, so slightly different shades of ‘green’. Such women with ‘4-colour’ vision have much better colour discrimination, they can distinguish between shades of red and green that most of us can’t. You can test this with a high quality colour spectrum print: men usually see 5-7 colour changes; these women typically see 7-9.
So? What’s the evolutionary advantage? Well, and here the menz should take a deep breath; if you are part of a pair-bond with a female, but you have been spreading your seed, and on your return you try to get away with it by telling porkies, the slight flushing, the minor facial reddening that comes with lying won’t be apparent to you, but she will see it. Menz, you just can’t win.


* This, strictly isn’t quite correct. There are ‘intersex’ variations, making the concepts much more complicated; see here for more.

  • chrisjones2

    Forgive me but why is this here?

  • Guest

    What is this? Encouraging new writers is laudable but encouraging one that is bluffing on so many subjects? Write what you know, don’t bullshit a 3 pager because you’ve been given a platform and can. Awful

  • Zig70

    Yeah but left to their own devices they stick Botulinum toxin in their faces and can’t tell the difference between plastic dolls and human qualities.

  • Brian O’Neill

    Korhomme is a retired medical consultant. This is his area. He is writting about it because of this whole dress thing that is doing the rounds.

    Sure this topic has bugger all to do with politics but You are under no obligation to read every post on slugger. You can merrily skip over to the next post that takes your fancy.

    If you think you can do better we are more than willing to publish new writers.

    contributors are free to stick up what they like but I will have a word with Korhomme to reduce the science lessons.

  • “They have better colour perception. Well, perhaps 20-50% of them do.”
    They don’t then. Have a better colour perception. According to your stats.
    The rest is bullshit.
    Someone needs to have a word with your ‘editor’.

  • Brian

    It’s bullshit. Did you not notice?

    “contributors are free to stick up what they like but I will have a word with Korhomme to reduce the science lessons”

    Science lessons?!

    Perhaps you might want to re-think that advice.

  • Kevin Breslin

    Colour vision isn’t the only aspect of vision, what about depth perception or field of view on a gender comparison. Are you seriously suggesting any ape which might be a human who unlike a bird of prey can see the colour red misses nothing in comparison to say a hawk or an eagle simply because they pick up a broader spectrum of frequencies?

  • Kevin Breslin

    Men did that toxin thing by eating rotten pork raw.

  • Brian O’Neill

    Well it seems to be valid that women perceive colour better than men http://news.nationalgeographic.com/news/2012/09/120907-men-women-see-differently-science-health-vision-sex/

    Anyway yes we realise this is straying from the slugger path. Some posts work and some posts don’t.

  • smcgiff

    Pot calling Kettle Black, Pete – or should that be gold?

    I found it interesting, and while not political it’s certainly topical.

    And while not mentioning any names some contributors could learn something from the simple and flowing writing syle.

    And regarding the science, if there is something you disagree with then challenge, it’s what slugger does well. No need to be snotty over it.

  • Brian O’Neill

    A bit of civility would not go amiss Pete. Not everyone is into cricket or astronomy but we don’t jump down your throat when you write about those.

  • Brian O’Neill

    Chris can you send me an email to brian@sluggerotoole.com I tried emailing you but it bounced back. Thanks.

  • Korhomme

    If there are gender differences in depth perception or in fields of view, I’m not aware of them. Our 3-D depth perception only works well up to about 15 feet, beyond this we use size as an estimation of distance.

    While we have a large field of view, our critical vision is confined to a very small area, perhaps 1º of vision. We make a ‘composite’ view by rapidly moving our eyes around the scene, and building a picture from that, even if we’re not fully aware of what’s happening. There is certainly a gender difference when we look at others; women looking at men, and men looking at women concentrate on different areas.

    It’s accepted generally that we can see green ‘better’ than other colours, meaning we can discriminate more shades of green, perhaps because the red and blue receptors overlap with the green (green being in the middle of the visible spectrum). Presumably, this has an evolutionary advantage, as does UV perception for some birds. (Some people, after their lens has been removed because of a cataract, are reported as being able to see some way into the UV.)

    There seem to have been three evolutionary pathways for ‘eyes’. Squids, for example, have a very different arrangement of nerve fibres and light receptors; you might well think that this seems to be a much more ‘intelligent design’:


  • Brian

    What’s this ‘we’, kemo sabe?

    The science content in the post isn’t the issue. It’s the context ‘korhomme’ has shoe-horned it into. And I may be detecting an emerging theme.

    Try reading that national geographic article you’ve linked.

    Females are better at discriminating among colors, researchers say, while males excel at tracking fast-moving objects and discerning detail from a distance—evolutionary adaptations possibly linked to our hunter-gatherer past. [added emphasis]

  • smcgiff

    Yeah, what has evolution ever done for us anyway.

  • Ben De Hellenbacque

    Love your staccato writing style. Is your perception of English grammar gender specific?

    Anyway I didn’t struggle with Korhomme’s full stops at all. I had to deploy that rather feminine of attributes, empathy, to permit me to understand your intention. However, that blokeish of features, evidence, is absent in your thesis. Has anyone ever spoken to your editor?

    If 20-50% of women have better colour perception than 100% of men there’s no struggle with understanding that either.

  • Granni Trixie

    I welcome this post – but assumed from its headline that it was creating space for a discussion about myths V facts about differences between men and women eg “they miss nothing” .
    Maybe it’s only my experience but women do seem better at multitaskimg – making the tea,keeping an eye on the children, listening to radio – and a bit or ironing to boot. Which,if representative, points to the importance of NURTURE over nurture. At the same time I think it is useful to untangle natural differences, acquired differences in the course of debates about equality of respect etc.

  • Croiteir

    Women are different from men – or is that vice versa – shocker