Why do human being laugh?

That is a question the human race has been asking forever and we still don't know the answer cold turkey there a Lot of theory's though we laugh at something that remind us that were human mistakes and so after a hard day of work watching some one slip on a banana peel ( making us reamber that were not work machines) make us laugh. (so laughing is a way of rejoicing in our life's in a way the way we jump back from a fire, its a reflex! and most people agree with this theory hope this helped