Humor

Humor is the quality of something being amusing or comical, especially as expressed in literature or speech. It can also mean a mood or state of mind of a person.

Empath: The Luckiest Smurf stories
In the EMPATH: The Luckiest Smurf story series, humor is a concept that is known among many races, including Smurfs, but is completely alien to the Psyches, who are taught by their society to be emotionless in their daily expressions and communications. Thus Empath during his first visit to the Smurf Village was confused when he received what he perceived to be a harmless gift from his fellow Smurf Jokey, only for it to turn out to be one of his "surprise presents". Over time Empath became used to humor being one of the ways that Smurfs express themselves and even learned to express it in his own personal way, with his most current expression being his flirtations with Smurfette before they were married. Polaris Psyche learned about humor through Empath's experiences and eventually became able to express it through his usual emotionless communications with other Smurfs.