The illusion of gender | Hacker News Reader

The illusion of gender

illusioncontest.neuralcorrelate.com

59 pointsrobg47 comments

The total lack of facial hair, even the slightest stubble on either of them has me classifying them both as female. I know they're the same pictures that are manipulated to make me 'believe' one is male the other female, but there is much more to identifying faces than just contrast, and absent other clues I seem to default to 'female'.

The reason there is no stubble is that these photos are composites (averages) of multiple faces. Any small irregularities in the original photos (not just stubble, but also wrinkles, blemishes, and facial asymmetries) are smoothed out through this process.

Incidentally, this is one of the theories behind why facial composites tend to be more attractive than the sum of their parts. Here's an interactive demo:

http://faceresearch.org/demos/average

Also, you can experiment with your own images here:

http://www.morphthing.com/

I think you just blew that site up by posting the link here!

This is a classic problem of averaging. The average of multiple data sets doesn't retain the average of all the properties of the originals. A simple case of this is averaging two similar images: the local variance will go down because you've blurred out detail and noise that varied between the two images.

Thus, as you average large numbers of images together, the composite you get is not necessarily representative of any of those that went in, and for that matter is not necessarily useful for any purpose at all, given that it didn't retain a lot of the properties of the input images.

Thats a great point. Two things come to mind:

1) Even if your wrong, and this does make a statement about how we perceive real faces, then contrast would only be a really useful indicator in the case of a very average face. Generally speaking it would probably be a very weak variable in our analysis.

2) It seems like they needed to find a way to separate out just the experimental variable in a way to make its amplitude higher than other variables. The only other way I can think of is to find someone who looks pretty much like the image. When looking at it, I don't see anything that makes me think its a composite (or strange, etc...).

Interesting how you get a more feminine face if you average (even if you average only male pictures).

Totally agree. The contrast makes no difference as to how I perceive the face. the look the same, except one is more tanned or something. Illusion fail, if you ask me. The faces seem female-shaped and the smoothness of the skin enforces that for me.

Consider me completely surprised. I'm still looking at both photos and trying to figure out why I key one in as male and one as female. And then trying to resolve that it's the same face!

I couldn't tell which one was supposed to seem female and which male, myself, although I have some problem differentiating faces, anyway.

The difference is much easier to perceive after further increase of contrast and brightness:

http://alteredqualia.com/visualization/hn/illusion-of-sex.pn...

Indeed. I had no trouble at all with the top one. Well, "trouble", given that this is an error. :)

I wonder if merely increasing the contrast of the lips is sufficient. Any photoshop experts want to try?

http://imgur.com/DPHAI

Although I used GIMP and I'm no expert. I'd say it's not as clearly masculine as the first version. *Edit: It's a version with the right subject copied from the left and the lips with less contrast - the original images were generated from a middle contrast image that isn't available.

Interesting, but it was the other case I was curious about: what happens if you give the "masculine" higher contrast lips?

http://imgur.com/wPIfm

So now the left is also the masculine image, but the lips have had their contrast increased.

Actually just playing with it, I can't turn the whole male image into the female one or vice versa. The GIMP tools probably have a subtly different effect than the ones the paper used.

Eyes (mostly eyelashes and eyebrows) are probably important too. Those are areas where make-up normally is applied to increase contrast. Same as lips.

Well, I guess this explains why women wear eye and lip make-up.

The correlation could be the other way since most guys are used to seeing women with make-up.

But women now have to keep wearing make-up in order to "keep up with" gender perception. (Or so one could argue.)

True but then it's nothing more than individual choice.

Do we have data from other cultures on this? Is makeup used to achieve the same effects in "all" cultures, especially ones that haven't been in contact with ours? Kinda hard to find new cultures to compare with, but descriptions from old time explorers etc should be useful.

Majority of Asian girls, be it Chinese, Japanese, Korean don't like to be tanned. Having light skin is seen as beautiful. I guess this could be related.

Well, the Egyptians invented eyeliner, but that had practical applications and both sexes used it.

Check the eyebrows too. We pluck them, and the contrast seems to cause that effect as well.

Except in many societies they don't.

I'm an American from the DC area who moved to Vienna, Austria.

The difference in dress and grooming between men and women here is nowhere near the grossly exaggerated level it was in the DC area.

Many parts of the US aren't as exaggerated as the DC area either, but it's a startling difference.

Women here rarely wear much makeup at all, don't run around in miniskirts in the winter, rarely wear impractical or dainty shoes, and don't dress up more than men on average.

It was quite a contrast with DC, where a significant portion of women would go on dates dressed up in fancy dresses, with fancy shoes, makeup, and jewelry, and their dates would be wearing khaki pants and polo shirts with ballcaps.

Women here are more like "real human beings." I caught myself thinking that way one day, with a kind of horror, but ruminating on it, it makes sense that the sexy, perfect image you devote your time to creating can backfire.

And, it's made me realize how similar men and women really look, if you took away head and facial hair.

(I joke about DC that you can't play "spot the hooker" because of the typical level of dress for women vs men.)

If my calculations are correct, women with clown makeup are the most attractive.

Did the copy get this right? It says the face with more contrast is perceived as female, but to me the more contrasty face is the one on the right, which I see as male. Adding to this, in my days as a retouch man, we'd add shadows and contrast to men's portraits, but remove it and soften for women's.

The pic on the right is definitely less contrasty than the one on the left. Look at the lips relative to the skin.

That said, it looks like it was a non-linear change to the contrast curve. The eyebrows have roughly the same tone in both images, as do the eyes. If I had to guess, the contrast was adjusted in the mid-gray region, with the extremes left unaffected. I'm also guessing that this illusion has to do with the contrast of skin tone between facial features -- not facial shadows (which can definitely affect the perception of beauty).

While the eyes look the same to me, the eyebrows look much lighter (and therefore thinner) to me in the higher-contrast image. (Perhaps we have different monitor curves?) I wish they had kept them the same, and only adjusted the contrast of the cheeks.

I think what they mean is that by increasing the contrast on the left picture many features stand out more, like the lips, and a lot of shadows "blend in" the face, which in turn makes it look smoother and rounder. Both of these characteristics are interpreted as more feminine. In the second picture you are able to distinguish a lot more shadows and that seems like a "stronger" bone structure.

(When I say stronger in the last sentence I mean with more extrusions etc but I cant think of the correct word right now, sorry)

I'd like to hear a theory about why this might be evolutionarily true. Was it because the men were out in the sun all day, decreasing the contrast of their skin, while women working together tend to have more contrast because they likely lived and worked in the shade?

If women worked in the fields tending crops while men hunted animals (in wooded areas), it could actually work out the other way around in terms of exposure.

In any event, its not clear that phenomena can have an evolutionary basis. Regardless of the perception of sexual gender in a potential mate, if the other is in fact of the same sex, there is no procreation, so its not clear how the selection mechanism would be operative. There are (to be polite) far more suggestive indicators of sexuality in the human body which are fairly readily apparent and far less prone to miscommunication.

http://www.youtube.com/watch?v=kRopmfinsWk

I remember reading that both sexes prefer less hair, but that testosterone keeps men hairy. Probably googling for a recent "naked ape" article would get it for you.

I wouldn't think evolution has anything to do with it. Quite simply, the face with lower contrast is perceived to be flatter. (The reason is purely geometric -- a curvier surface contains a wider range of angles-of-incidence with respect to the lighting source, thus resulting in a higher-contrast image.)

By placing the two images next to each other, our brain assumes that they are illuminated by the same lighting source, immediately tags one as "round" and one as "flat". Women, by the very nature of having "higher cheekbones" (and typically more facial fat), have rounder cheeks. Thus, if the brain tries to tag the two images as different sexes, it's much more likely to tag the higher-contrast (rounder-looking) face as female and the lower-contrast (flatter-looking) face as male.

Helping (hurting?) the situation is also the fact that the black level of the eyebrows was not kept constant when adjusting the contrast, thus causing them to lighten and look thinner in the higher-contrast image. Women tend to have thinner eyebrows (at least in modern society, due to the fashion trend of eyebrow plucking), no doubt lending weight to the brain's decision.

As to why women have higher cheekbones and more facial fat, well that question I'll have to defer to an evolutionary biologist :)

Men have darker skin because of higher levels of hemoglobin (partly due to not bleeding every month). Maybe that makes the skin in the face more ruddy, decreasing contrast with the lips and eyes.

The example here (and the theory that the more the contrast, the more "female") is too black-and-white (no pun intended). It's not just contrast - there is a reason why women are called the "fairer sex". A face that is whiter, has no visible facial hair (and smooth skin) is natually perceived as female.

I don't really think this classifies as an illusion. Granted, it is fascinating that a simple change in contrast can cause our perception to change, but I don't quite track with how this is considered an illusion.

Why change "sex" into "gender" in title?

The original article title and the scientific article title have the word "sex".

Seriously, WTF? I am reminded of "gender mainstreaming" conspiracy theories some of my friends have. Is word "sex" a taboo?

Yay! A taboo!

The 'male' picture seems darker - did they control for that?

The post doesn't mention which is which. Holy shit. What if I got it wrong? (Please don't be alarmed. I'm just being overly dramatic.)

It does actually.

"One face was created by increasing the contrast of the androgynous face, while the other face was created by decreasing the contrast. The face with more contrast is perceived as female, while the face with less contrast is perceived as male."

You mean the illusion of sex. Sex and Gender are not the same.

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