system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why we laugh

What's the point of laughing and where did it come from? It just seems like an unnatural response in nature - for instance, dogs don't laugh. ELI5 please!
gpt
Back in man's early days, it was used to signal that everything was okay. Laughter's supposed two main components are incongruity and safety. Incongruity means something isn't right. Safety obviously means you are far from harm.