Balok laughing
Data laughing
Laughter was a physical reaction in sentient beings for expressing mirth, satisfaction, or derision. The act of making laughter was called laughing.
In humanoids, laughter was a movement of certain muscles of the face, especially around the mouth, resulting in a lighting up of the face and eyes. It was accompanied by the emission of explosive or chuckling sounds from the chest and throat.
After suspending his relationship with T'Pring in 2259, Spock attempted to engage more with his Human side, which included laughing. This effort would ultimately prove to be short-lived and was largely forgotten by history. (SNW: "Those Old Scientists")
In 2365, Commander William T. Riker served as first officer on the Klingon vessel IKS Pagh as part of the Officer Exchange Program. He found himself the subject of various ribald jokes and later expressed that in all of his dealings with Klingons, including Lieutenant Worf, the thought never occurred to him of Klingons laughing. (TNG: "A Matter Of Honor")
In 2366, Q granted Data a bout of laughter in gratitude for his assistance when Q was briefly made mortal. (TNG: "Deja Q")
After installing the emotion chip in 2371, Data gained the capacity to laugh of his own accord, but then began to do so in uncontrollable fits when the chip malfunctioned. (Star Trek Generations)
In 2374, the Dream Aliens trapped members of the crew of the USS Voyager in nightmares, prior to snaring them in a collective unconsciousness. Although several of them chose to share the contents of their nightmares, Lieutenant Commander Tuvok was not among them. Vulcans not being known for outward displays of emotion, B'Elanna Torres wondered just what a Vulcan nightmare would be like. Neelix then speculated "Alone, exiled on a planet where the only form of communication is laughter." (VOY: "Waking Moments")
In 3189, the USS Discovery computer suggested that one way Captain Saru could heal the crew was through laughter. According to the computer, sentient beings found laughter to be both healing and meaningful. It then recommended the 20th century comedians Buster Keaton and Charlie Chaplin, who were known as "communal unifiers without the burden of language".
Later that day, the computer showed the Buster Keaton movie Sherlock Jr. in the ship's shuttlebay for the crew. Watching the film, they were healed and unified through laughter. (DIS: "Forget Me Not")