Australasian Science: Australia's authority on science since 1938

The Soul of Wit

By Tim Hannan

Laughter may be the best medicine, but some jokers may be incurable.

Just in time for the Melbourne Comedy Festival, a new study has explored the phenomenon of incessant joking by patients with brain injuries. First described in the 1880s, the pathological compulsion to tell jokes is known in the scientific literature by the German term Witzelsucht. Patients with this affliction are relentless in their attempts to make humorous remarks, which include puns, slapstick or other forms of lowbrow humour. Some repeatedly utter sexual or scatological comments in socially inappropriate situations.

Sufferers appear unaware that their behaviour is abnormal, and do not modify their joke-telling in response to feedback. While finding their own jokes and stories immensely amusing, they generally don’t find other peoples’ jokes funny at all.

In February clinicians from Los Angeles described two cases of Witzelsucht in the Journal of Neuropsychiatry and Clinical Neurosciences ( One was a 69-year-old man with a 5-year history of compulsively telling jokes to his wife. To prevent him from repeatedly waking her during the night to tell jokes, she persuaded him to write them down, resulting in 50 pages of chiefly sexual or scatological humour such as:

Q. What is a pill-popping sexual molester guilty of?
A. Rape and pillage; and

Q. What did the proctologist say to his therapist?
A. All day long I am dealing with a**holes.

His compulsion to joke was attributed chiefly to the effects of damage to both the left caudate nucleus and a lesion to the right frontal cortex, both caused by cerebrovascular accidents.

The second case described a 57-year-old man whose joke-telling increased over a 3-year period, accompanied by the development of childish or inappropriate behaviour. Like the first patient, he found his own jokes hilarious while the jokes of others didn’t amuse him. On investigation he was found to have atrophy in the frontal regions as a result of Pick’s disease, a form of frontotemporal dementia.

The leading contemporary approach to understanding humour is the “incongruity-resolution model”, which suggests that humour appreciation requires the integration of multiple pieces of information. In most cases, a joke involves conflicting propositions that the person must detect and then resolve. Thus “getting the joke” involves appreciating the incongruity of the punchline with what precedes it, and the discovery of a way to make these congruent gives rise to emotionally pleasurable responses experienced as humour.

Damage to specific brain regions is presumed to disrupt these cognitive mechanisms. Previous experimental studies conducted with neurological patients had found that those with right frontal damage regions preferred punchlines that are simplistic and don’t require the integration of multiple pieces of information. The present study’s authors propose that those with Witzelsucht also have a problem integrating information, so they cannot readily resolve incongruities in complex jokes. This explains their preference for simple humour such as children’s riddles and puns, and probably results from damage to the right frontal regions.

The compulsive nature of the joke-telling in Witzelsucht is thought to result from a second deficit in inhibition systems mediated by connections between the frontal lobes and sub­cortical systems. This explanation is consistent with the brain damage documented in the recent cases, with both having right frontal damage along with frontal-subcortical involvement.

The authors note that appreciating humour is not the same as laughing, and that Witzelsucht is to be distinguished from pathological laughter, a condition in which patients start laughing in the absence of any discernible cause, are unable to stop, and where the laughter is incongruent with their apparent mood. In Witzelsucht, patients are amused by their own jokes, even if not by the jokes of others.

A/Prof Tim Hannan is Head of the School of Psychology at Charles Sturt University, and the Past President of the Australian Psychological Society.