Guy Deutscher - Through the Language Glass, Why the World Looks Different in Other Languages

No doubt further areas of language will be explored when our experimental tools become less blunt. What about an elaborate system of evidentiality, for example? Recall that Matses requires its speakers to supply detailed information about their source of knowledge for every event they describe. Can the habits of speech induced by such a language have a measurable effect on the speakers’ habits of mind beyond language? In years to come, questions such as this will surely become amenable to empirical study.

When one hears about acts of extraordinary bravery in combat, it is usually a sign that the battle has not been going terribly well. For when wars unfold according to plan and one’s own side is winning, acts of exceptional individual heroism are rarely called for. Bravery is required mostly by the desperate side.

The ingenuity and sophistication of some of the experiments we have encountered is so inspiring that it is easy to mistake them for signs of great triumphs in science’s battle to conquer the fortress of the human brain. But, in reality, the ingenious inferences made in these experiments are symptoms not of great strength but of great weakness. For all this ingenuity is needed only because we know so little about how the brain works. Were we not profoundly ignorant, we would not need to rely on roundabout methods of gleaning information from measures such as reaction speed to various contrived tasks. If we knew more, we would simply observe directly what goes on in the brain and would then be able to determine precisely how nature and culture shape the concepts of language, or whether any parts of grammar are innate, or how exactly language affects any given aspect of thought.

One may object, of course, that it is unfair to describe our present state of knowledge in such bleak terms, especially given that the very last experiment I reported was based on breathtaking technological sophistication. It involved, after all, nothing short of the online scanning of brain activity and revealed which specific areas are active when the brain performs particular tasks. How can that possibly be called ignorance? But try to think about it this way. Suppose you wanted to understand how a big corporation works and the only thing you were allowed to do was stand outside the headquarters and look at the windows from afar. The sole evidence you had to go on would be in which rooms the lights went on at different times of the day. Of course, if you kept watch very carefully, over a long time, there would be a lot of information you could glean. You would find out, for instance, that the weekly board meetings are held on floor 25, second room from the left, that in times of crisis there is great activity on floor 13, so there is probably an emergency control center there, and so on. But how inadequate all this knowledge would be if you were never allowed to hear what was being said and all your inferences were based on watching the windows.

If you think this analogy is too gloomy, then remember that the most sophisticated MRI scanners do nothing more than show where the lights are on in the brain. The only thing they reveal is where there is increased blood flow at any given moment, and we infer from this that more neural activity is taking place there. But we are nowhere near being able to understand what is “said” in the brain. We have no idea how any specific concept, label, grammatical rule, color impression, orientation strategy, or gender association is actually coded.

When researching this book, I read quite a few latter-day arguments about the workings of the brain shortly after trawling through quite a few century-old discussions about the workings of biological heredity. And when these are read in close proximity, it is difficult not to be struck by a close parallel between them. What unites cognitive scientists at the turn of the twenty-first century and molecular biologists at the turn of the twentieth century is the profound ignorance about their object of investigation. Around 1900, heredity was a black box even for the greatest of scientists. The most they could do was make indirect inferences by comparing what “goes in” on one side (the properties of the parents) and what “comes out” on the other side (the properties of the progeny). The actual mechanisms in between were mysterious and unfathomable for them. How embarrassing it is for us, to whom life’s recipe has been laid bare, to read the agonized discussions of these giants and to think about the ludicrous experiments they had to conduct, such as cutting the tails off generations of mice to see if the injury would be inherited by the offspring.

A century later, we can see much further into the mechanisms of genetics, but we are still just as shortsighted in all that concerns the workings of the brain. We know what comes in on one side (for instance, photons into the eye), we know what goes out the other side (a hand pressing a button), but all the decision making in between still occurs behind closed doors. In the future, when the neural networks will have become as transparent as the structure of DNA, when scientists can listen in on the neurons and understand exactly what is said, our MRI scans will look just as sophisticated as cutting off mice’s tails.

Future scientists will not need to conduct primitive experiments such as asking people to press buttons while looking at screens. They will simply find the relevant brain circuits and see directly how concepts are formed and how perception, memory, associations, and any other aspects of thought are affected by the mother tongue. If their historians of ancient science ever bother to read this little book, how embarrassing it will seem to them. How hard it will be to imagine why we had to make do with vague indirect inferences, why we had to see through a glass darkly, when they can just see face-to-face.

But ye readers of posterity, forgive us our ignorances, as we forgive those who were ignorant before us. The mystery of heredity has been illuminated for us, but we have seen this great light only because our predecessors never tired of searching in the dark. So if you, O subsequent ones, ever deign to look down at us from your summit of effortless superiority, remember that you have only scaled it on the back of our efforts. For it is thankless to grope in the dark and tempting to rest until the light of understanding shines upon us. But if we are led into this temptation, your kingdom will never come.

Humans can see light only at a narrow band of wavelength from 0.4 to 0.7 microns (thousandths of a millimeter), or, to be more precise, between around 380 and 750 nanometers (millionths of a millimeter). Light in these wavelengths is absorbed in the cells of the retina, the thin plate of nerve cells that line the inside of the eyeball. At the back of the retina there is a layer of photoreceptor cells that absorb the light and send neural signals that will eventually be translated into the color sensation in the brain.

When we look at the rainbow or at light coming out of a prism, our perception of color seems to change continuously as the wavelength changes (see figure 11). Ultraviolet light at wavelengths shorter than 380 nm is not visible to the eye, but as the wavelength starts to increase we begin to perceive shades of violet; from around 450 nm we begin to see blue, from around 500 green, from 570 yellow, from 590 orange shades, and then once the wavelength increases above 620 we see red, all the way up to somewhere below 750 nm, where our sensitivity stops and infrared light starts.

A “pure” light of uniform wavelength (rather than a combination of light sources in different wavelengths) is called monochromatic. It is natural to assume that whenever a source of light looks yellow to us, this is because it consists only of wavelengths around 580 nm, like the monochromatic yellow light of the rainbow. And it is equally natural to assume that when an object appears yellow to us, this must mean that it reflects light only of wavelengths around 580 nm and absorbs light in all other wavelengths. But both of these assumptions are entirely wrong. In fact, color vision is an illusion played on us by the nervous system and the brain. We do not need any light at wavelength 580 nm to perceive yellow. We can get an identical “yellow” sensation if pure red light at 620 nm and pure green light at 540 nm are superimposed in equal measures. In other words, our eyes cannot tell the difference between monochromatic yellow light and a combination of monochromatic red and green lights. Indeed, television screens manage to trick us to perceive any shade of the spectrum by using different combinations of just three monochromatic lights-red, green, and blue. Finally, objects that appear yellow to us very rarely reflect only light around 580 nm and more usually reflect green, red, and orange light as well as yellow. How can all this be explained?