Send to

Choose Destination
Am Nat. 2006 May;167(5):E117-39. Epub 2006 Mar 23.

The structures of letters and symbols throughout human history are selected to match those found in objects in natural scenes.

Author information

Sloan-Swartz Center for Theoretical Neurobiology, California Institute of Technology, Pasadena, California 91125, USA.


Are there empirical regularities in the shapes of letters and other human visual signs, and if so, what are the selection pressures underlying these regularities? To examine this, we determined a wide variety of topologically distinct contour configurations and examined the relative frequency of these configuration types across writing systems, Chinese writing, and nonlinguistic symbols. Our first result is that these three classes of human visual sign possess a similar signature in their configuration distribution, suggesting that there are underlying principles governing the shapes of human visual signs. Second, we provide evidence that the shapes of visual signs are selected to be easily seen at the expense of the motor system. Finally, we provide evidence to support an ecological hypothesis that visual signs have been culturally selected to match the kinds of conglomeration of contours found in natural scenes because that is what we have evolved to be good at visually processing.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for University of Chicago Press
Loading ...
Support Center