5 Comments

Are you familiar with Johann Wolfgang von Goethe's "Theory of Colours" and "Remarks on Colour"? And how his observations, which are not so much a theory as they are descriptions of perceptions may interplay with your hypothesis for the evolutionary function of color vision?

Expand full comment

Yes and no. I am vaguely aware, and always appreciated his more psychological approach, looking for the meaning of and relations between colors. …rather than the to-me physics envy psychophysics schools on color that don’t provide any insight. But… I never got too familiar with him.

Expand full comment

I came across Goethe's "Theory of Colours" in recent readings of Rudolf Steiner, who Goethe's writings had an oversized impact on. Steiner wrote, "The Philosophy of Freedom." He was aligned with theosophy and then founded anthroposophy, the concept of "spiritual science." He designed and built the Goetheanum. I don't know enough yet about those ideas and concepts, still new to me. But connecting concepts of color as you describe we were evolved to understand others with and be empaths to these philosophers who explored deeper meanings in color strikes me as an interesting rabbit hole to explore.

Expand full comment

So, blacks are color-blind?

Expand full comment

Excerpt from my earlier book, Vision Revolution….

When I tell people about my hypothesis for the evolutionary function of color vision, one out of every two people asks me, “What about those with very dark skin? Do they show these color modulations?” Sometimes the question is in the spirit of academic criticism: at some point all humans had very dark skin, so if skin color signals don’t show on dark shades of skin, then color vision must not be for seeing skin coloration. However, even if it were true that color signals cannot be seen on very dark skin, color vision evolved long before humans did, and our ancestral primates may well have had lighter skin. (Primates with color vision have a wide variety of skin colors, as you can see for yourself by looking ahead to Figure 9.) If this were the case, our color vision would not have been particularly beneficial while we had dark skin, but it would have become useful as some humans spread around the globe and gradually acquired lighter skin.

Many of those who ask the question aren’t interested in academic points but are merely curious. Darwin was also curious about this. In his book The Expression of the Emotions in Man and Animals, he writes,

Several trustworthy observers have assured me that they have seen on the faces of negroes an appearance resembling a blush, under circum- stances which would have excited one in us [Caucasians], though their skins were of an ebony-black tint. Some describe it as blushing brown, but most say that the blackness becomes more intense (318).

He follows this with,

It is asserted by four of my informants that the Australians, who are almost as black as negroes, never blush. A fifth answers doubtfully, re- marking that only a very strong blush could be seen, on account of the dirty state of their skins. Three observers state that they do blush; Mr. S. Wilson adding that this is noticeable only under a strong emotion, and when the skin is not too dark from long exposure and want of cleanli- ness. Mr. Lang answers, “I have noticed that shame almost always ex- cites a blush, which frequently extends as low as the neck” (319–320)

Concerning such observations, one must take into account that many of these observers were Caucasian and likely raised in an envi- ronment where lighter skin was the baseline. We would expect such individuals to be less capable of discriminating skin color deviations around a dark-skinned baseline. For example, Darwin writes that,

Von Spix and Martius, in speaking of the aborigines of Brazil, assert that they cannot properly be said to blush; “it was only after long intercourse with the whites, and after receiving some education, that we perceived in the Indians a change of colour expressive of the emotions of their minds” (318).

Although the implication is that the aborigines’ education led to greater blushing, it is much more plausible—to put it mildly—that it was the whites’ experience with aborigine skin color that eventually trained them to perceive it.

Skin color variations are visible on the darkest skin, and even Cau- casians with less exposure to darker ranges of skin colors can notice the changes. This is because, whether dark or light, human skin pos- sesses a reflectance spectrum with the same signature features (see Figure 3), and later we’ll see that the spectrum changes in the same way as the two blood variables, concentration and oxygenation, vary

Expand full comment