Transformation of a metaphor: semantic shift in a Cantonese term 'Chi Sin' denoting insanity.

OBJECTIVES The historical evolution of the existing terms used to describe insanity may be able to shed light on the formation of stigma towards psychosis patients. In Hong Kong, a widely used Cantonese term for insanity 'Chi Sin' provides a unique example because of its neutral original sense, as it literally means misconnection in a network circuit. We attempt to trace the origin and subsequent evolution of the term 'Chi Sin' from its early use to the present day to understand how local Hong Kong people have attached increasingly negative connotations to this scientific term since the mid-20th century. METHODS We sampled as many newspapers and magazines published in Hong Kong from 1939 to June 2014 as possible, and sampled 7 popular local movies from the 1950s and 1960s. We also searched all the newspapers published in Hong Kong, Macau, Taiwan, and Mainland China from January 1998 to June 2014, and searched several other local historical resources. RESULTS In one early use of 'Chi Sin' in 1939, the term was only used in a technical sense to describe 'short circuiting'. We found that the development of the telephone system, the Strowger system, in Hong Kong is closely related to the evolution of the semantics of the term 'Chi Sin'. CONCLUSIONS The original meaning of short circuitry of the term 'Chi Sin' is no longer used, and it has become a dead metaphor through repeated use with negative emotional connotations. This illustrates some of the factors facilitating the emergence of a metaphor with subsequent semantic drift.