The Language Log's discussion of umami got me thinking about Berlin and Kay's research on basic color terms. An explanatory quote from their post:

[H]ere's a quote from I.E.T. de Araujo, M. L. Kringelbach, E. T. Rolls, and P. Hobden, Representation of Umami Taste in the Human Brain, J Neurophysiol 90: 313-319, 2003:
Recently, the taste referred to by the Japanese word umami has come to be recognized as a "fifth taste" ... (after sweet, salt, bitter, and sour; umami captures what is sometimes described as the taste of protein). In fact, multidimensional scaling methods in humans ... have shown that the taste of glutamate [as its sodium salt monosodium glutamate (MSG)] cannot be reduced to any of the other four basic tastes. Specific receptors for glutamate in lingual tissue with taste buds have been also recently found. Umami taste is found in a diversity of foods like fish, meats, milk, tomatoes, and some vegetables, and is produced by the glutamate ion and also by some ribonucleotides (including inosine and guanosine nucleotides), which are present in these foods.

So Japanese has a word for a whole dimension of taste that goes almost unrecognized in English. This is a great example of cultural relativity, which would claim that the categories by which we define tastes are different because we're lacking a word for a certain basic taste.

One could make the same argument about colors. English speakers have a set of basic colors like red, yellow, blue and orange. All other colors seem to come from those colors: teal is a "type of" blue. Who's to say that another culture can't have teal as one of its basic colors, and that the color we call blue is, for them, a type of teal? To put it another way:

"There is a continuous gradation of color from one end of the [color] spectrum to another. Yet an American describing it will list the hues such as red, orange, yellow, green, blue, purple--or something of the kind. There is nothing either in the spectrum or human perception of it which would compel its division in this way." (Gleason, 1961, from Palmer, 1999)

In the same way, there's nothing in the "spectrum" of flavors that would incline a language to divide it up into the sweet/bitter/salty/sour classification we've got in English.

Or is there?!?!

Well, the cultural relativity of color took a beating from Berlin and Kay, who basically discovered that every culture has approximately the same set of basic colors. There's no culture that teaches its kids about fuschia and ochre before it teaches them about red and blue. Red and blue are universally important. This discovery about categorization has a basis in the structure of our visual hardware. If we have neurons in our retinas that respond to red, yellow, green and blue (which it looks like we do), that would explain why those colors are so salient for us. In other words, it seems like our retinal receptors do much of the categorization for us, and so our basic color categories are determined by the fact that we're human, not by the fact that we speak English.

But the same setup has been found in the biology of taste, and yet taste words don't exhibit the same phenomena. There are receptors for five types of taste, so every language should have around 5 basic flavor words. What gives?

There are essential differences between sight and taste. Flavor has always been a bit trickier to describe than color. Colors can be arranged on a spectrum, tastes cannot. Still, it's hard to see how these differences account for the difference in categorization.

Another possibility: Berlin and Kay talked about languages that gain new color terms as the language develops. Perhaps the addition of "savory" to our taste lexicon is a step in the evolution of English, or something. Again, that sounds iffy.

It's terribly inconsistent and I demand to know who is responsible.

Update: I must be new at this. (Palmer, 1999) is Vision Science by Stephen Palmer (MIT Press). Encyclopedic textbook of all things vision-related ("visionary"?).