Laughter can be healing and transforming, helping us to let go of anxiety and fear and anger. I recall being in a rather intense argument with a patient who was not at all happy that I didn't want to give him the medications he thought he should have. He became quite loud and threatening. I tried to remain calm, but I was aware that my responses were becoming more edgy, irritated, and a little fearful of what might happen if the argument escalated any further.
There was a pause as we reached an impasse, and we looked at each other. Then we started to laugh, he first, and then me. The tension was broken. We didn't immediately agree but we agreed to discuss the situation again later. We've got on well ever since.
But laughter can also be cruel, as when people laugh at another persons misfortune. The more deliberate it is, the more cruel it can be. If we inadvertently make someone smile at something we've done and they're struggling to hide a laugh, we can learn to laugh with them and diffuse the situation. But deliberate taunting laughter makes us want to go away and hide. It's shaming, embarrassing.
Those who laugh at our misfortune, particularly if they have caused it, are sadistic. Think of those who laughed as they watched their victims walk into the gas chamber, or who laugh as they rape and torture and starve their victims. Such laughter is demonic.
Does Satan have a sense of humour? It's not something I've ever seen discussed. I've seen references to God's sense of humour. (I've made them myself). One of the psalms refers to God laughing at his enemies' plans in derision. But I've never thought of Satan having a sense of humour. Perhaps that's because he laughs only at others' misfortune. He laughs to increase others' suffering, not to reduce it.
But shared laughter can bind people together. It can break down barriers. Laughter between friends or family members over shared experiences is bonding. The laughter itself becomes an event to be recalled and smiled about later.
People from different cultures are amused by different things, although slap-stick humour tends to be universally a cause of laughter. Even different age groups find different things funny. Children apparently laugh hundreds of times a day, whereas adults laugh less and less as they grow older. Is that because we lose our sense of humour as we age, or because laughter involves incongruity and surprise? As experience increases with age, less and less surprises us.
The humour of many comedies comes in taking a well known situation and twisting it slightly. We think we know what to expect and then it happens differently. People don't do what we were expecting. Which raises the question of whether the gospel is really great comedy. Something which should make us laugh out loud. Not because it's ridiculous, but because it's ridiculously funny that God would do something so unexpected. (See Psalm 126.2.)