• Posted June 24, 2026

Belly Laughs Spring From The Primitive Brain, Researchers Say

Ever bark with laughter when something funny hits you out of left field? Or get a case of the giggles so bad you can’t stop, even though your sides ache?

That sort of spontaneous laughter might originate from a more primitive part of the human brain, researchers reported June 23 in the journal Trends in Neurosciences.

What’s more, the brain region associated with those belly laughs is completely different from the region that produces a chuckle in response to a joke from your boss or witty repartee at a social gathering, researchers found.

This dual-system model of laughter might shed new light on psychiatric conditions that can cause uncontrollable laughter, including seizure disorders, mood disorders, Alzheimer’s disease and schizophrenia, researchers argue.

It also might help explain why laughter is described as the best medicine.

The brain regions linked to spontaneous laughter also are involved with emotional regulation, researchers noted. Stimulating them produces laughs accompanied by enhanced mood, euphoria and mirth.

And one of those regions — the anterior cingulate — is an important player in the brain’s pain-dampening system.

“The role of these circuits in pain modulation is also intriguing,” lead researcher Fausto Caruana, a senior research scientist with the National Research Council of Italy, said in a news release. “We are interested in further investigating the analgesic role of laughter and the neural circuits that support it.”

In the study, researchers teased out the differences between spontaneous laugher and volitional laughter, or the more controlled laughter that happens during the course of interaction with someone.

“Think about the last time you were laughing and you could not stop,” senior researcher Sophie Scott, a senior research fellow at University College London in the U.K., said in a news release. “Something set of you off and you are helpless with mirth.”

That’s spontaneous laughter. The other type, volitional laughter, is anything but spontaneous, researchers said.

“That’s most of the laughter you encounter,” Scott said of volitional laughter. “It’s timed incredibly precisely. If you look at people having a conversation, they will laugh together at the end of a sentence and then breathe together.

“When people are talking to each other, volitional laughter starts and stops really quickly,” Scott added.

To better understand these differences, researchers turned to reports of pre-surgical brain stimulation in epilepsy patients.

During these procedures, clinicians electrically stimulate different parts of a person’s brain while they are awake, to identify which regions are causing seizures. This stimulation often unintentionally evokes laughter in the patient.

Based on those observations, researchers argue for the existence of two distinct brain networks underlying laughter:

• The spontaneous network consists of regions involved in motor control and emotions, including the pregenual anterior cingulate cortex, nucleus accumbens and the temporal pole.

• The voluntary network consists of areas involved purely in motor control of laughing and smiling, like the rolandic operculum, globus pallidus and presupplementary motor area.

Stimulation of the voluntary network regions will produce laughter in patients, but without the positive emotions that come from stimulation of the spontaneous network.

Researchers think the spontaneous network is a more evolutionarily ancient pathway that arose in animal rough-and-tumble play, which produced laughter-like vocalizations meant to prevent aggression and promote social bonding.

On the other hand, the voluntary network overlaps with brain regions that produce speech. Researchers said that supports the notion that it controls conversational, purpose-driven laughter.

Caruana hopes that these findings can serve “as a kind of Rosetta stone for decoding multiple aspects of communication and the social use of vocalizations.”

More information

Case Western Reserve University has more on the benefits of laughter.

SOURCE: Cell Press, news release, June 23, 2026