Humor is theorized to have started out as an early signal between primitive humans that there was no danger present and could therefore relax and interact with each other socially, making it an evolutionary strength that certain humans possessed and others didn’t.
Our ancestors had different vocalizations that signaled a wide range of things, but the main two that are important here were “danger” and “play”. Individuals who could determine that they were safe and make the noises that signaled “play” were thought of to be ‘funny’ in a way. In the same vein, these noises were an early form of laughter, which is most likely the reason why most people today laugh when presented with something humorous.
The early humans who couldn’t pick up on the cues of safety would lash out or react in strange ways, which wouldn’t help them find mates and pass on that gene. Vice versa, those who thought a “danger” signal was the opposite easily became casualties from their inability to be serious in a serious situation, which also led to that gene not being passed on either.
Humans who could differentiate between danger and safety passed on their genes, eventually leading to us taking pleasure in jokes today. Instead of humor being thought of as a form of safety now, it’s more used for bonding and fun and we’re able to understand more complex jokes than millions of years before.
For instance, we could use a joke about a fly walking into a bar. First of all, we know that flies don’t walk into bars, providing us with a small puzzle that our brains want to make sense of. It creates a small underlying sense of anxiety because we want the situation to be resolved in a logical way.
That’s where the punchline of the joke comes in, which is that the fly goes up to a man at the bar and says, “I like the stool you’re sitting on.” The word “stool” can have two meanings: the object we sit on, and poop. Our brains were able to make an understanding of the initial part of the joke (but not directly because of the double meaning of “stool”), which eases the sense of anxiety from the set up and amuses us.
As a whole, humor is associated with positive emotions and making social connections with others, making it a huge part of human nature and a key part of life.