[3][4][5] Wang has made contributions to the genetic classification of Sinitic languages and their typological peculiarities, including the study of its tones.
An important early paper outlining this theory was "Competing Changes as a Cause of Residue" published in the journal Language.
[22] In an article titled “Tone change in Chaozhou Chinese: A study in lexical diffusion,”[23] he disputed the Neogrammarian assumption of “sound laws” in the ways that the phonetic inventories of languages evolve, with the changes putatively applying swiftly and across the board to classes of sounds.
Consistent with his later position that grammars leak, he pointed out exceptions to sound classes in the spread of changes.
"[31] In 1984 he published a commentary critiquing Bickerton's "Language Bioprogram Hypothesis" target article[32] in the journal Behavioral and Brain Sciences, arguing against the Chomskian perspective that language was largely independent of other aspects of cognition:"...the fact that language involves biological equipment does not necessarily lead to the "highly modular task-specific cognitive devices" and "equally modular and task-specific processing component" that Bickerton advocates.
The devices used in language are surely involved in the more global (and evolutionarily prior) tasks of cognition, memory, and perception.
To posit anything specific to language, in the sense that it serves no other non- linguistic function, seems to me not called for at this point"[33]In 1996 Prof. Wang co-authored another commentary in Behavioral and Brain Sciences arguing that syntax was not likely an independent cognitive module:"The belief that syntax is an innate, autonomous, species-specific module is highly questionable.
Syntax demonstrates the mosaic nature of evolutionary change, in that it made use of (and led to the enhancement of) numerous preexisting neurocognitive features.
In 1986 Wang and Cavalli-Sforza co-authored a paper showing a strong correlation between geographic distance and lexical difference among Micronesian languages.
[44] Wang collaborated with several geneticists on a study of Y-chromosome DNA variation as a means to infer population history of East Asia.
[45] Wang was co-author on a paper on brain structure/function with the biochemist and anthropologist, Vincent Sarich, who was a pioneer in molecular evolution.
He is among the first to have conceived of languages as complex adaptive systems, with emergent patterns in constant state of flux and in search of equilibrium, a position that makes it easier to account for the actuation of the so-called “internally-motivated change.”.
Wang argued that linguists should try to understand the phenomenon of complexity itself, in light of modern research on the subject matter in other disciplines, especially cybernetics.
[52] Another study involved assessing the strength of associations between a variety of cognitive tasks - including several tapping linguistic functions specifically - with brain size and some basic brain subcomponents measured using structural MRI on a set of sibling pairs (to control for between-family environmental effects).
[46] In collaboration with Paul Kay and others he investigated the activation of language regions during color perception using functional MRI.
[53] He co-authored a functional MRI study exploring the neural bases of congenital amusia in tonal language speakers.
[54] He has also co-authored research using EEG event-related potentials to study the time course of context-dependent talker normalization in spoken word identification,[55] and has also contributed to work investigating EEG delta, theta, beta, and gamma brain oscillations during different levels of auditory sentence processing.
[57] He helped found the Research Centre for Language, Cognition, and Neuroscience at the Hong Kong Polytechnic University in 2019.
(23 papers in English and Chinese, 271 pages) 2005: POLA Forever: Festschrift in Honor of Professor William S-Y.
(25 papers in English and Chinese, 419 pages) 2013: Eastward Flows the Great River: Festschrift in Honor of Professor William S-Y.
(17 articles in English and Chinese, 237 pages) William Shi-Yuan Wang will be awarded an honorary doctorate at the University of Macau on December 2, 2023.
In 1996 he was Principal Investigator of a Chiang Ching-kuo Foundation grant to do research on the Yao languages of South China.