> Why do people, invited for a dinner party at 7.30, think its cool to arrive at 8.30? It’s rude. It’s inconsiderate. And it’s selfish...

Some people here are saying that dinners are different than parties: that you really do need to be on time. I also tended to believe that. Especially, one would imagine, for "particularly special dinner occasions" such as organized holiday events. Hence, when I was invited to Thankgiving dinner this year, and was tasked with bringing the stuffing, I considered it horrible of me that I was arriving ten minutes late--due to my oven's starter stopping working halfway through my preparations I had to find a candle-lighter, delaying some of my cooking preparations--and sending notices to the other people by SMS.

However, when I got there, no one was there but the host, and he was nowhere near done cooking anything. No one else arrived for a half hour, and that was just one person. Most people didn't arrive until a couple hours later, and some people didn't arrive until a few hours later. If anything, the host was concerned that he had confused me into taking the time of the event too literally.

It isn't like there was a bunch of time wasted: we were having a get-together... the goal is to spend time with a bunch of people and have fun, and everyone's schedules are going to be somewhat different from each others. It isn't actually critical that everyone eats at the exact same moment, and it certainly isn't important that everyone hears every moment of every single conversation.

I thereby want to say that this is more of a culture thing than anything else. Here's one way to tell: when that person who was late tries to make a plan with you, come late next time and see if they get angry. Frankly, I bet they don't, and that they don't even seem at all phased: they ended up doing something else to keep the time passing, and weren't even closely paying attention to when you would arrive. Yet, I bet you will still be angry; in fact, I further bet you will even be angry that the other person isn't angry ;P.

Yes: to you this is really important. Maybe for the kind of event you want to have it actually is important (carefully prepared food will be ruined if people didn't eat it at the right moment, you are putting on a play and you actually need the actors to be there, etc.). However, that doesn't mean it is important in all circumstances or that even in the same circumstance it is considered important to all people.

It doesn't even mean that that kind of event is optimal, or that everyone else wants to have that kind of event. If it is actually important to you, be prepared to defend why it is important, be prepared to only be able to make that case occasionally, and keep an open mind to compromising with others who do not share your opinion that every event is better if everyone arrives at exactly the same moment.

A term that is sometimes used for this phenomenon is "cultural cross-talk", and a classic example is how long you wait before someone else is done talking before it is no longer considered you "butting in" when you start to speak. Different people from different backgrounds and different cultures have different expectations of how this should work, and if you aren't aware of this you end up getting really angry.

As a concrete example, the way this would apparently work in American Indian societies would involve very long silences: just because no one is now talking it is not to be assumed that the person who was speaking before isn't just collecting their thoughts to continue to speak again. To presume otherwise would be very rude, and it isn't like you need to be in a rush: you thereby should continue to wait until it is clear that the other person has ceded the floor.

On the other hand, in some places (I believe New York is the typical example; I'm from Chicago, however, and also have this tendency) you see a negative amount of time before the other person is supposed to start talking: yes, people seriously are predicting in their minds what the other person is saying so when it seems like they are coming to the end of a thought they can start speaking while that other person is still talking.

Both of these are normal and neither are "rude": they are just cultural expectation. However, one can easily imagine people from a culture expecting patience and clear turn order to write a massive rant claiming that "no, you are not 'anticipating my sentence final intonation'; you are rude and selfish", making the argument that the other person "isn't listening to me and just wants to hear themselves speak... they even talk over what I'm saying, and I can't get a word in edgewise".

But no, it really is just a difference in expectation. You see these same differences in situations like whether it is rude to ask for things, whether it is rude to deny people asking for things, whether it is rude to presume you can share something, whether it is rude to look at someone, whether it is rude to talk to someone, and whether it is rude to make any form of physical contact at all with someone (or even to stand close enough to someone that physical contact could be possible). People are simply different: that doesn't make them "rude".