Kindred strokes for different folks

Natural History, April, 2005 by T.J. Kelleher

Greek or Latin, Hebrew or Mongolian, Tagalog or Tamil, most of the writing systems devised throughout human history are at heart surprisingly similar--and the similarities are probably not coincidental, say two neurobiologists, Mark A. Changizi and Shinsuke Shimojo of Caltech.

Writing is orderly mark making. In nonpictographic writing systems (such as the alphabet you're reading right now), lines, loops, and other strokes are combined to form individual characters--letters and numbers. Characters that are hard to write and (probably more important) hard to read are unlikely to catch on. In contrast, characters made of just a few simple strokes stand a far better chance of surviving.

Changizi and Shimojo studied more than a hundred writing systems, and what emerged was a consistent economy of expression. Each character, on average, is made up of three strokes, no matter how many characters occur in the writing system. Such economy might be explained by earlier findings that people can store roughly three objects at a time in visual short-term memory. Even more astounding is the redundancy of the average character: even if half of its constituent strokes are removed, it remains potentially recognizable. (Proceedings of the Royal Society of London B 272: 267-75, 2005)