Spock and Doug high five.
A high five was the Human act of slapping another individual's raised (five-fingered) hand as a gesture of greeting or celebration. An invitation to high five was "up top" or "give me five", which could optionally be followed by the acts of "down low" (lowering the hand and slapping again) and "too slow" (dodging the other person's slap).
In 2261, Commander Pelia invited Captain Christopher Pike to high five during a briefing for a mission to Tezaar. A short time later, Spock taught Doug how to high five. (SNW: "Four-and-a-Half Vulcans")
In 2382, a couple of Harry Kims from the multiverse high fived each other. (LD: "Fissure Quest")
In 2383, a holographic version of Spock explained to Dal R'El, who had attempted the Kobayashi Maru scenario the meaning of the no-win scenario and the importance a captain must have in understanding and listening to their crew. He then bids Dal farewell with the Vulcan salute, which Dal misinterprets as a high five. (PRO: "Kobayashi")