Why do letters look the way they do?

What do the shapes on the left all have in common? What about those on the right? (Pictured, from top: Roman, Greek, Hebrew, Arabic, and Devanagri scripts.)

When you look at this image, do you know what all of the shapes on the left have in common? How about the shapes on the right?

If you know how to read more than one of those languages, then you may think the answer is that they represent the same sound, or have the same name. While that’s not a bad answer, what would you think if I told you that what all of the shapes on the left have in common is that they all came from a drawing of an ox? And on the right, a drawing of a house?

The shapes above on the left originally were a representation of an ox, and those on the right a house! Can you see the resemblance?

This is true because of how many of the world’s writing systems evolved—through a process where the earliest written symbols were pictographic or ideographic. That basically means that the most ancient forms of writing represented an idea by drawing an image to represent it… the shape of an ox’s head to represent “ox”, or the outline of a house to represent “house”.

Although the details are lost to history, researchers do know that over time these shapes became abstracted away from their origins as obviously visual representations. Instead of a symbol representing a whole word or an idea, they started to represent the smallest units of human language: “phonemes”, the basic pieces of our words. It is this evolution that allowed a drawing of an ox, which was called “alep” or “alef” in ancient Semitic languages, to represent just the first sound of that word—and why the language you are reading right now calls this letter “A”!

A drawing of an ox’s head (“alep”) becomes more abstract, and stands in for just the first sound–“a”. If you turn this familiar letter, “A”, upside down, you can still see the ox’s head.

Of course, this evolution of what written symbols represent does not explain why our shapes look the way they do—while it’s pretty easy to see how an “A” looks like an ox, it’s not so obvious for other letters. And indeed, some letters (or entire writing systems, like Korean Hangul) never began as depictions of real objects. While it’s hard to say with certainty why the shapes of our letters are what they are, some fascinating research suggests a couple of probable factors that drove our distant ancestors to create the shapes that they did. 

In Mesopotamia, the cuneiform writing system was produced using a stylus on clay tables (top), whereas in Egypt hieroglyphs were carved into stone or inked onto papyrus (middle), and in China free-flowing forms developed with the use of brushes (bottom). Notice that early shapes (top rows) look like pictures of the actual objects, but with time (lower rows) they became more abstract–in both appearance and meaning.

One of those historical factors is the medium in which the language was written. If you’ve ever tried to sign your name on a painting using a brush, or chisel it into a sculpture, you know that the tools you use have a major impact on what you are able to create. Cultures that prominently used clay or stone to write were likely influenced by those media in a way that lead to very different types of shapes than those that used ink and brushes—and the advent of the printing press or, in more recent times, computers, lead also to fundamental changes in typography.

Intersecting lines and curves are all around us. Can you see the T’s, L’s, V’s, Y’s, etc., all over this scene?

Another possible factor that may explain the shapes of our letters comes from nature. Some researchers have argued that the prevalence of certain shapes across different languages, like L-shapes and T-shapes, are a reflection of what shapes we encounter naturally in our environment (Changizi et al., 2006). Think about how a tree trunk meets the ground to form an upside-down T-shape, or how the shoreline of a lake creates a C-shape. It turns out that such intersections which naturally occur more often are also more common in writing systems across the world and history (so for example, shapes like L are very common, but shapes like A are less so).

Watch a short clip of Hubel and Wiesel’s classic experiment.

One last clue as to why our shapes look the way they do comes from what we know about brain activity in response to viewing letter-shapes like this. In visual cortex (the occipital lobe), there are neurons that respond preferentially to certain types of stimulation, which we call “visual features”. Pioneering experiments by Hubel & Wiesel in the 1960’s helped pave the way for understanding this basic phenomenon. There are groups of neurons that become particularly excited when they see lines of certain orientations, for example responding much more to a line at 45° then a line at 0° (horizontal); other neurons may prefer lines that intersect each other like in an X; still others, to closed circles like O as opposed to open ones like C. This property of visual cortex most have evolved not for the purposes of reading, but rather for recognition of objects and scenes—and it is consistent with the possibility that our letters tend to use the same shapes as those we see frequently in our environment!

References/Further reading:

• Changizi, M. A., Zhang, Q., Ye, H., & Shimojo, S. (2006). The structures of letters and symbols throughout human history are selected to match those found in objects in natural scenes. The American Naturalist167(5), E117–E139.

• Hubel, D. H., & Wiesel, T. N. (1968). Receptive fields and functional architecture of monkey striate cortex. The Journal of Physiology195(1), 215–243.

• Daniels, P. T., & Bright, W. (Eds.). (1996). The world’s writing systems. Oxford University Press on Demand.