Hacker News Reader

Comment by bouncingsoul | Hacker News Reader

The article contains a couple claims I'd never heard before. I did a quick search:

– The linked article is all I could find about men having better stereoscopic vision.

– All women being able to see a fourth primary color is not at all agreed on, but there may be some who can: http://en.wikipedia.org/wiki/Tetrachromacy

I don't see how either trait necessarily correlates with being a better hunter or gardner. Are people who see a fourth primary color better at picking the ripe tomatoes? Maybe. But it makes sense isn't science.

View on HN

"Women are thought to have the ability to see a fourth primary colour "

I'm pretty sure this is an urban legend. If not, all color theory through the history of art would be male-only. Women should have different screens (RGB would not be enough to show a realistic picture), different films, printers and so on. How can anyone seriously believe that?

The wikipedia article says that tetrachromacy is theoretically possible in women, and that two persons in the world have been identified as possibly tetrachromatic. That is quite a different issue.

How would a tetrachromat perceive a website through standard CRT/LCD/LED screens that are based on 3 channel (RGB) color? Is there any difference?

If they just have an extra "channel" in the eye in addition to the standard three, a RGB image would look the same to a tetrachromate as it looks to us. However, the rest of the world would look much more nuanced and colorful to them, hence the RGB image will look flat and colorless, like say an image where the red channel has been removed looks colorless to us.

It's basically impossible for us to comprehend how rich and colorful the world looks to e.g. birds which has tetrachromatic eyes.

I'm pretty skeptical about the idea that men have wider eye spacing because it makes us better hunters. If eye spacing had any significant effect on hunting ability I'm pretty sure we'd find ourselves with eyes spaced as far apart as possible, but instead we find there's actually a fair bit of room on either side. Widely-spaced eyes are a pretty "cheap" evolutionary adaptation.

Unless it introduces reduced capability in say snow, depth perception or against bird predators.

As I recall, having eyes fairly close together (not on seperate sides of the face) is something which tends to be associated with predators/carnivores, while herbavores tend to have their eyes very far apart to increase the area which they can locate things - like predators - in.

In other words, if you want to see everything around you, your eyes should be far apart, but if you want to be very good at focusing on something you're hunting, they should be closer together.

Though I don't remember where I heard this, and hence cannot provide a citation.

It sounds pretty likely... though I think tree-dwelling creatures (like many of our recent-ish ancestors) tend to have eyes on the front of their head even if herbivorous -- examples include possums, sloths, koalas, monkeys. I'd guess depth perception is pretty important when you're climbing a tree.

Anyway, I'm certainly not arguing that binocular vision isn't good for hunting, I'm just saying that the extra few millimeters distinguishing men from women probably doesn't help much. I'm pretty sure men have more widely-spaced eyes than women cuz we're just plain bigger than women (a fact which _does_ actually help with hunting).

The reasoning given for the traits is probably the second hand version of an off-handed conjecture of a TA in an intro level Anthropology course.

At the same time, if the traits are found in a large part of the population (50%?) the cause for their selection could very easily be related to acquiring food.

Reply on news.ycombinator.com