The Laughing Brain: The Neuroscience Behind Comedy 

Imagine yourself sitting in front of your television watching Saturday Night Live (SNL). Michael Che just blurted a line on the Weekend Update segment “the CDC [is] warning people not to eat raw cookie dough because it may contain germs that cause diarrhea, but on the bright side, you can eat cookie dough without gaining weight!” [1].  Not much thought goes into your laughter– as it is an innate physical reaction that comes as naturally as crying [2]. But, have you ever wondered why that line evoked such a reaction from you, but not from your mom who was also watching the show alongside you? In the neuroscientific community, there is a dearth of knowledge on the science behind comedy [3]. Following that intrigue, this article will investigate the neuroscience behind laughter and comedy by utilizing existing research to foster a strong understanding of this topic and potential areas to be investigated in the future. 

To explore comedy, we must first understand the science behind it, beginning with what are known as the four existing humor styles [4]. The first being self-enhancing (SE) humor, which is defined as good-natured humor that enhances the self at no expense of others [4]. The second humor style is affiliative (AF) humor, which fits the same criteria as self-enhancing, but it is meant to enhance relationships with others rather than oneself [4]. The third is aggressive (AG) humor, which is humor meant to enhance oneself at the expense of others. Finally, there is self-defeating (SD) humor, which is humor meant to elevate relationships with others, [4] but at the expense of oneself. With that understanding, one can dive into the parts of the brain involved in this comedy journey. 

In multiple studies, brain activity has been found in areas associated with the varying types of humor styles [5,6]. For example, SE and AF humor types are associated with activation in the nucleus accumbens (NAc), which is located in the forebrain and is part of a reward circuit [7]. They are also affiliated with activation in the midbrain, which is also associated with reward [8]. Finally, activation has been found in the ventromedial prefrontal cortex (vmPFC) in the prefrontal lobe, which is associated with emotional responses [9]. These structures are involved in the mesolimbic and mesocortical pathways, which play a role in reward, pleasure, and cognition [10]. The mesolimbic and mesocortical dopamine pathways utilize neurotransmitters (e.g., dopamine), which are chemicals released in the brain that help transmit signals and messages, to relay information responsible for motivation, reward, attention, and various other functions [10]. Thus, activation in these reward systems can result in laughter [11]. AG and SD humor are associated with activation of the subgenual anterior cingulate cortex (sgACC), located in the frontal lobe, and the amygdala, located in the medial temporal lobe, with both regions contributing to emotional regulation [6,12,13].

The findings above indicate there are slightly different neural regions mediating cognitive processing of benign (SE & AF) versus more aggressive (AG & SD) humor [6]. The limbic-frontal activity is highlighted in aggressive types of comedy (SD & AG), indicating that humor activity is presented more broadly within the brain. However, the connectivity highlighted in benign humors (AF & SE) are narrowed down more to the midbrain areas with mesolimbic-temporal-frontal connectivity [6]. Both types of humors are involved in reward systems within the brain – just different regions! Now that there is an established understanding of the four humor styles’ brain functions, one can now look towards understanding the state of mirth/humor and laughter they produce. 

Beyond humor-style lies the physical mechanism of mirth and laughter. Mirth can be defined as a state of humor or happiness that is generally accompanied by laughter [14], whereas laughter is simply a motor behavior [5]. Therefore, when one is in a state of mirth, the areas of the brain described above (e.g., vmPFC, sgACC, etc.) may be activated depending on what style of comedy is being consumed [5]. Separate, yet deeply connected to mirth, is laughter. Laughter is thought to occur from activation in the anterior cingulate cortex (ACC), which as previously discussed is involved with emotion regulation [12]. Although, it should be noted that laughter is not dependent on mirth to produce a humor response in the brain [5]. Following this understanding of these brain mechanisms and components comes the exploration of the cognition of comedy. 

Cognition, defined as thinking, reasoning, judging, problem-solving, awareness, and more, is the conscious part of comedy [15]. Understanding the neural mechanisms of comedy is far easier than understanding why comedy exists and its cognitive development. A proposed theory from Matthew Hurley and colleagues is that humor and mirth are “cognitive events” resulting from an unconscious realization that a mistake has been made in social norms (e.g., eating soup with a fork, the wrong way on an escalator, saying ‘have a good meal ' to a waiter, etc.) [16,17]. While the resulting good-feeling is “humor is the brain’s reward for discovering unexpected errors” [16]. Essentially, the brain detects non-threatening errors, such as the ones mentioned above, and in turn, it has developed to release pleasurable feelings (via dopamine) to indicate that that danger is not present [17]. 

Beyond comedy serving as an indication of an all-clear from danger, lies theories that humor developed as social capital [11]. There is speculation and hypotheses that humor may have evolved, and may continue, to serve as a mechanism for socialization and choosing a suitable partner or friends rather than just serving as an error detector [11,17]. Findings from a partner desirability study indicated that “individuals desired a partner high in humor production and receptivity” [18]. In this social capital theory, humor is serving as an indicator of higher intelligence, as it is difficult to fake this form of intelligence because people will not fake laugh just so one can gain their partner or friends of choice [11].

There is still no definitive answer as to why comedy and laughter exist, but progress is being made towards a greater understanding of these processes. Areas of comedy research that could use further exploration are: generational changes in comedy; the social and evolutionary advantages of comedy additionally, the link between comedy and intelligence. What is certain is that comedy and laughter serve an important role in people’s everyday lives and will not be going anywhere anytime soon. So, next time you find yourself laughing at SNL you may find yourself thinking “what type of comedy is this?, why am I laughing?” you may actually be able to answer those questions.

References:

[1] Saturday Night Live. (2018, December 16). Weekend Update: Colin Jost and Michael Che Swap Jokes - SNL [Video]. Youtube. https://www.youtube.com/watch?v=YRfN-UGoKJY

[2] Kappas, A. (2009). Mysterious Tears: The Phenomenon of Crying from the Perspective of Social Neuroscience. In T. Fögen (Ed.), Tears in the Graeco-Roman World (pp. 419-438). Berlin, New York: De Gruyter. https://doi.org/10.1515/9783110214024.419

[3] Libera, A. (2020). The science of comedy (sort of). AMA Journal of Ethics, 22(7), 602-607. https://doi.org/10.1001/amajethics.2020.602

[4] Martin, R. A., Puhlik-Doris, P., Larsen, G., Gray, J., Weir, K. (2003). Individual differences in uses of humor and their relation to psychological well-being: Development of the Humor Styles Questionnaire. Journal of Research in Personality, 37(1), 48-75. https://doi.org/10.1016/S0092-6566(02)00534-2

[5] Caruana, F., Avanzini, P., Gozzo, F., Francione, S., Cardinale, F., Rizzolatti, G. (2015). Mirth and laughter elicited by electrical stimulation of the human anterior cingulate cortex. Cortex, 71. 323-331. https://doi.org/10.1016/j.cortex.2015.07.024 

[6] Chan, YC., Hsu, WC., Liao, YJ., Chen, HC., Tu, CH., Wu, CL. (2018). Appreciation of different styles of humor: An fMRI study. Scientific Reports. https://doi.org/10.1038/s41598-018-33715-1

[7] Know your brain: Nucleus accumbens. (2014, June 13). Neuroscientifically Challenged. Retrieved November 14, 2021, from https://neuroscientificallychallenged.com/posts/know-your-brain-nucleus-accumbens

[8] Midbrain. (n.d.) Neuroscientifically Challenged. Retrieved November 14, 2021, from https://neuroscientificallychallenged.com/glossary/midbrain

[9] Ventromedial prefrontal cortex. (n.d.). ScienceDirect. Retrieved November 14, 2021, from https://www.sciencedirect.com/topics/neuroscience/ventromedial-prefrontal-cortex

[10] Mesolimbic pathway. (n.d.). ScienceDirect. Retrieved November 14, 2021, from https://www.sciencedirect.com/topics/neuroscience/mesolimbic-pathway

[11] Hurley, M. M., Dennett, D. C., Adams, R. B. Jr. (2011). Inside Jokes. The MIT Press. https://ebookcentral.proquest.com/lib/templeuniv-ebooks/reader.action?docID=3339581

[12] Anterior cingulate cortex. (n.d.). Neuroscientifically Challenged. Retrieved November 14, 2021, from https://neuroscientificallychallenged.com/glossary/anterior-cingulate-cortex

[13] Amygdala. (n.d.). Neuroscientifically Challenged. Retrieved November 14, 2021, from https://www.neuroscientificallychallenged.com/glossary/amygdala?rq=amygdala

[14] Merriam-Webster. (n.d.). Mirth. In Merriam-Webster.com dictionary. Retrieved September 29, 2021, from https://www.merriam-webster.com/dictionary/mirth

[15] American Psychological Association. (n.d.). Cognition. In American Psychological Association dictionary. Retrieved November 14, 2021, from https://dictionary.apa.org/cognition

[16] Rodden, A. (2011). Neuroscience: What makes us laugh. Nature, 473. 450. https://doi.org/10.1038/473450a

[17] Miller, G. (2001). The mating mind: How sexual choice shaped the evolution of human nature. Psycholoquy, 12(8). 

[18] Tornquist, M., Chiappe, D. (2015). Effects of humor production, humor receptivity, and physical attractiveness on partner desirability. Evolutionary Psychology, 13(4). https://doi.org/10.1177/1474704915608744