The Predictable Evolution of Letter Shapes

Abstract

A familiar story about the evolution of alphabets is that individual letters originated in iconic representations of real things. Over time, these naturalistic pictures became simplified into abstract forms. Thus, the iconic ox's head of Egyptian hieroglyphics transformed into the Phoenician and eventually the Roman letter A. In this vein, attempts to theorize the evolution of writing have tended to propose variations on a model of unilinear and unidirectional progression. According to this progressivist formula, pictorial scripts will tend to become more schematic while their systems will target smaller linguistic units. Objections to this theory point to absent, fragmentary, or contrary paleographic evidence, especially for predicted transitions in the underlying grammatical systems of writing. However, the forms of individual signs, such as the letter A, are nonetheless observed to change incrementally over time. We claim that such changes are predictable and that scripts will in fact become visually simpler in the course of their use, a hypothesis regularly confirmed in transmission chain experiments that use graphic stimuli. To test the wider validity of this finding, we turn to the Vai script of Liberia, a syllabic writing system invented in relative isolation by nonliterates in ca. 1833. Unlike the earliest systems of the ancient world, Vai has the advantage of having been systematically documented from its earliest beginnings until the present day. Using established methods for quantifying visual complexity, we find that the Vai script has become increasingly compressed over the first 171 years of its history, complementing earlier claims and partial evidence that similar processes were at work in early writing systems. As predicted, letters simplified to a greater extent when their initial complexity was higher.

Simplification Is Not Dominant in the Evolution of Chinese Characters

“…Following previous studies (Garrod et al, 2007 ; Kelly et al, 2021 ), we define the visual complexity C of an image as its perimetric complexity (Arnoult & Attneave, 1956 ; Pelli et al, 2006 ): where P is the sum of the interior and exterior perimeters of the image, and A is its area. Perimetric complexity has been shown to predict several aspects of human perception including the efficiency, accuracy and speed of recognizing letters and characters from multiple scripts including modern Chinese (Chang et al, 2016 ; Pelli et al, 2006 ; Wang et al, 2014 ; Wiley et al, 2016 ; Zhang et al, 2007 ).…”

“…If we focus on visual complexity in particular, experimental work (Garrod et al, 2007 ) and a prior analysis of the Vai script (Kelly et al, 2021 ) both suggest that written symbols tend to be relatively complex when first created but become simpler as they are repeatedly used. These results led us to anticipate similar changes in written Chinese, but in retrospect we see two important differences between our work and the studies of both Garrod et al ( 2007 ) and Kelly et al ( 2021 ). First, both previous studies trace the evolution of symbols from their moment of birth onwards, but the earliest forms in our analysis are drawn from a time at which Chinese characters had already been in use for hundreds of years.…”

“…However, few palaeographers subscribe to a strictly deterministic view of script evolution whether in terms of scribal media, social function or contact. For example, technological shifts in the production of the Vai script, from reed pens to modern pencils and digital fonts, do not account for any substantial changes in visual complexity, nor indeed did standardisation campaigns or shifts in genre (Kelly et al, 2021 ). The reality that the Egyptian hieroglyphic script was transformed into the much simpler hieratic script is in no way negated by the continued and concurrent use of the hieroglyphic script for monumental display.…”

“…This idea is compatible with a broader literature on signed, spoken and written language that emphasizes ways in which linguistic systems are shaped by the need to support efficient communication (Gibson et al, 2019 ; Keller, 2005 ; Kirby et al, 2015 ; Tamariz & Kirby, 2015 ; Zipf, 1949 ). Just as speakers simplify and shorten words in order to communicate with greater efficiency (Kanwal et al, 2017 ), written symbols undergo comparable transformations that remove superfluous graphical details and reduce visual complexity (Changizi & Shimojo, 2005 ; Dehaene, 2009 ; Garrod et al, 2007 ; Kelly et al, 2021 ; Pauthier, 1838 ; Trigger, 2003 ).…”

The stranding of the ideography: A nonnegligible role of the spoken language

“…Ideography can also teach us about the human brain's difficulties in dealing with visual codes such as writing. Our brains' visual areas can be recycled to process letter shapes by repurposing hardwired circuits that evolved to treat other stimuli (Dehaene, 2010;, helped by the fact that letter shapes are optimized to fit our visual brains' native constraints (Changizi, Zhang, Ye, & Shimojo, 2006;Kelly, Winters, Miton, & Morin, 2021;Morin, 2018). In spite of the flexibility of human neural and cultural resources, learning to read never became as natural as learning to speak, and remains a tall order for around 5% of the schooled population (Ramus, 2004;Wagner et al, 2020).…”