Today I Learned (TIL)

According to about 12 seconds of googling this article feels borderline. This article specifically references a 2010 study that says 12% of women carry the gene however the article fails to mention what the study specifically says. In the opening paragraph if the study it says "However, the existing evidence is sparse and inconclusive." & "Our results suggest that most carriers of color anomaly do not exhibit four-dimensional color vision, and so we believe that anomalous trichromacy is unlikely to be maintained by an advantage to the carriers in discriminating colors."

I found three different studies regarding this. One said that it was about 15% of women, one said it was 50% of women and 8% of men. Another said that women with color vision defficiency and mild color blindness might have tetrachomacy effectively rendering the extra cones pointless. ANOTHER study showed that only one person EVER had been diagnosed with Tetrachomacy.

While I really appreciate media that brings to light conditions that the average person might not know about I really dislike articles and media that make things seem way more common then they are and/or portray things as fact that are far more nuanced. We already have enough people self diagnosing themselves or self identifying with abilities/disabilities

There is a lot of misinformation about tetrachromacy and sadly this article perpetuates some of it. 12% of women are dormant tetrachromats, which means they have extra sets of cones but don't actively use the extra ones. And the article suggests men are "less likely" to be tetrachromats, which is technically true, but misleading, since men cannot be tetrachromats at all.

(person points to blue)

Me: blue.

(Person points to purple)

Me: blue-ish?

(Person points to aqua)

Me: blue but like... Different?

(Person realizes I just suck with colors)

Tetrachromacy is real, and does improve the range of colour differentiation in people who have it, but the headline here greatly exaggerates the degree to which that is true.

https://www.youtube.com/watch?v=fDoAs0qN7lU

The title is predicated on the idea that 1 cone = 100; 2 cones = 100^2^ = 10,000; 3 cones = 100^3^ = 1,000,000; so having 4 cones = 100,000,000. But this is misleading, because once you have three kinds of cones, any point within the visible range has its own unique response. The 4th cone improves the ability to make fine differentiations (the examples in other comments here are fantastic demonstrations of that), but doesn't add entirely new colours.

Sort of like how 3 towers are enough to triangulate someone's location on a map. A 4th tower might make the triangulation go easier, or give you more confidence in your result, but it doesn't fundamentally alter your understanding.

This is how we found out my mother had it:

Mom: "The colours on this new TV are terrible. Everyone is green."

Me: "Okay, hold on, let me adjust the tint."

Mom: "Now they're too blue."

Me: adjusts the colour temp

Mom: "Ew, now everyone is too yellow, it's like the Simpsons."

• one hour later of adjusting each setting by one step *

Mom: "Well, it's still not right, but it's less awful."

A few years later I found out about Tetrachromacy tests online, and she scored something like 98%.

Is the difference in the eyes or brain?