Jokes don't necessarily make the atmosphere friendly or relaxed. Lots of jokes are in some way cynical or sarcastic, which works much better amongst friends tha

Jokes don't necessarily make the atmosphere friendly or relaxed. Lots of jokes are in some way cynical or sarcastic, which works much better amongst friends than amongst strangers. Jokes also make the policy of acceptability much more blurry. It's relatively easy to find broad agreement on whether a comment is true/useful/kind, than it is on whether the comment is funny.