Humour is a universal human phenomenon that can evoke positive emotions and social bonding, and even produce therapeutic effects. But what is the science behind humour? How does the brain process and respond to humorous stimuli?

The neurobiology of humour is complex and multifaceted, involving multiple brain regions and cognitive processes. At its core, humour involves the recognition of incongruity, or surprise, which creates a cognitive conflict that is resolved through laughter or other positive emotions. And what happens in the brain when we encounter something funny?

Humour in the brain

Humour, or its manifestation as laughter, is universal. In infants, laughter is one of the first social vocalizations. For the longest time, it was thought to be a simple behavioural reflex response to certain situations — but it turns out that it is more complex than that. Humour is a higher-order cognitive process that involves both perception and creativity, as well as the integration of affective stimuli. 

One of the key brain regions involved in humour is the prefrontal cortex, which is responsible for executive functions such as attention, working memory, and inhibitory control. Studies have shown that humour comprehension recruits activity in the prefrontal cortex, suggesting that humour requires cognitive resources and mental effort. 

Humour also involves the amygdala, a brain region that is involved in emotional processing and the generation of emotional responses. When we encounter something funny, amygdala activity increases, leading to the release of dopamine and other neurotransmitters that generate positive emotions and reward signals. 

Other important brain regions involved in humour are the ventromedial prefrontal cortex and temporoparietal junction, which are associated with social cognition and theory of mind, and are associated with activation during self-related processing. 

Theory of mind is the phenomenon and ability of one to empathize with others and put themselves in someone else’s shoes. The activation of the brain regions implicated in theory of mind suggests humour is a social and communicative phenomenon that involves understanding other people’s perspectives and intentions. Changes in the oxygen levels in the blood, which signal to reward system areas such as the mesocorticolimbic pathway, are also observed in subjective funniness ratings.

The cognitive component of humour is thought to rely on visual, auditory, and language areas, as humour can be processed both verbally and visually. Language areas such as Wernicke’s area, which is important for comprehension, and Broca’s area, which is used for speech production, play a key role in the semantic processing and production of humorous stimuli.

Do we need humour?

Interestingly, humour does have an evolutionary, functional role in society. Its fundamental basis in evolution is its ability to create, facilitate, and maintain social bonding and interactions by allowing people to express their sometimes negative and tense feelings in a more positive light. This is also known as the tension-relief theory, which identifies humour as a physiological mechanism for tension release. Hence, people who engage in humour and laughter experience a sense of relief by releasing tension. 

Another evolutionary function of humour relates to sexual selection. Laughter is an indicator of fitness, signalling an attractive quality in mates for women choosing their partners. This explains why so many women find funny men attractive!

Research has also shown that humour can have therapeutic effects on mental health by reducing stress, anxiety, and depression, and improving subjective well-being. This is thought to be due to the activation of the mesolimbic reward system, which is involved in the generation of positive emotions and the regulation of stress responses.

The neuroscience behind humour is a complex and fascinating area of research that involves the integration of a plethora of sensory and semantic elements. By understanding the neural mechanisms that underlie humour, we can gain insights into the nature of human cognition and social behaviour and develop new approaches for treating mental health problems.