Laughter has been extensively studied by Darwin (1890). Van Hooff (1972; 1989) traced the phylogeny of smiling and laughter to non-human primate “grin-face” and “play face”, which signals non-serious attacks. Human cognition evolved beyond primate “play”, with human laughter expanding to a wider range of social contexts (Gervais and Wilson 2005). Henceforth, smiling/laughter has been considered an expression of joy at varying intensities. The universality of this expression was studied by Ekman et al. (1982; 1990), identifying two universal kinds of smiles/laughs: felt (Duchenne) and fake (non-Duchenne)—the latter appearing in uncomfortable situations. Ekman and Friesen’s (1976, 1978) Facial Action Coding System distinguishes 44 action units, with AU6 and AU12 being the Duchenne smile marker (Martin et al., 2017), while AU12 alone signals a non-Duchenne smile (Ekman, 1990). Preliminary observations noting signs of discomfort such as non-Duchenne smiles, and gaze aversion (Tangney 1999), showed Tunisians exhibiting such signs when speaking in Modern Standard Arabic (MSA). In diglossic Tunisia, Low (Tunisian Arabic) and High (MSA) varieties coexist (Ferguson 1959), whereby code-switching may be appraised as incongruous, a source of humour for observers (Ferguson, 1959). This may elicit hearer amusement (even laughter) and speaker embarrassment for violating sociolinguistic norms (Goffman, 1956). This paper hypothesises that switching to MSA, results in embarrassment, manifesting through non-Duchenne smiles (AU12 only; Ekman, 1990), an expression associated with social discomfort, along with other embarrassment signs. This social emotion may relate to a broader negotiation of an ethno-cultural pan-Arab identity, prompting a re-evaluation of MSA pedagogy.
Lilia Ben Mansour (2026) studied this question.