Humour comprehension and use of mental state language in William Syndrome and Down Syndrome

Good humor comprehension and mental state language use is reported to be associated with good theory of mind (ToM) capabilities. There is limited research on humor comprehension in Williams Syndrome (WS) and Down Syndrome (DS), but related research in non-literal language and humour comprehension in people with intellectual disabilities suggest humor comprehension may be impaired in these populations. Furthermore, there is mixed evidence for ToM in WS and DS and limited research exists on the use of mental state language in either WS or DS. So far, the literature suggests that people with WS have are good at inferring emotions, however both WS and DS individuals have difficulties with producing cognitive language (e.g., thinks, believes). The current study sought to examine humour comprehension and use of mental state language in WS and DS relative to one another and relative to neuro typical controls, as well as the relationship between humour comprehension and mental state language use. Participants (30 WS; 18 DS; 27 CA; 30 MA controls-17 MA matched to WS; 13 MA matched to DS) were shown 23 cartoon jokes and were asked to explain what was funny. The results revealed poor humour comprehension in WS and DS relative to CA matched controls, but WS and DS individuals showed a comparable performance to each other and to MA matched controls. Furthermore, the groups only differed on the use of physical emotion words (e.g., laughing, crying, screaming) and cognition words (e.g. thinks). WS used fewer physical emotion words than DS and CA matched controls, but their frequency of use was equal to MA matched controls. The DS group did not differ relative to either CA or MA matched controls. Regarding use of cognition words, both WS and DS groups used fewer than CA controls, but performed similarly to each other and to their relative MA matched controls. Lastly, humour comprehension was not associated with humour comprehension for WS or DS individuals, only CA and DS MA matched controls. The study provides unique findings and evidence for humour comprehension in WS and DS that is similar to MA levels, but below CA levels. Results highlight the importance of intellectual ability in processing humour. Social implications and avenues for future research are discussed.

Humour is an important aspect of daily human life across the world. Laughter is a pattern of vocalizations in response to a humorous stimulus, and is one of the first social vocalizations produced by an infant, after crying McGhee [1]. We encounter humour in many different forms in our day to day lives, including interpersonal joking and banter, comedy films and TV shows and cartoons in newspapers, books, or on the internet Martin [2]. Humour is considered an essential phenomenon for successful social interaction Yip & Martin [3], as it aids in communicating ideas, feelings and opinions Nezlek & Derks [4].

To produce humour, one needs to be able to process information from the environment or from memory and manipulate ideas, words and actions to generate a funny action or comment. Understanding humour involves processing the meaning of the humorous stimuli that has been heard or viewed, and appraising it as humorous and non-serious Martin [2].

Although there are many theories of humour comprehension, one of the most widely accepted is the incongruity-resolution theory Suls [5].The theory states that in order to understand humour, one first needs to detect an incongruity, which is usually an outcome that does not conform to the prediction the recipient made. Then the next step is to resolve the incongruity by finding a rule that makes the ending follow from the rest of the joke. Accordingly, understanding humour is viewed as a problem solving task.