When I moved to Switzerland, our relocation package included a class to help me acclimate to my new culture. The instructor used a helpful analogy in understanding the differences between Swiss and US communication and relationships.
She described Swiss relationships as a pineapple. The outside is very difficult to penetrate, but once you have passed that difficult, thin layer the remainder of the experience is quite sweet and refreshing. Swiss tend to be difficult to approach, but once you do the relationship is open and warm.
She described US relationships as a peach. The initial approach is fuzzy, soft, and easy to penetrate but as you get deeper the center is hard. Americans tend to have lots of friendly casual relationships, while genuine deep relationships are few and highly prized.
The Swiss culture is one that is neutral, while the US culture is one that is affective.
At any time -- a meeting, guest interaction, or a simple conversation with a Colleague - both reason and emotion play a role. Members of affective cultures readily show emotions by laughing, smiling, grimacing, scowling - even crying, shouting, or walking out of the room. People who are from cultures that are emotionally neutral in their approach do not telegraph their feelings, but keep them carefully controlled and subdued.
This doesn't mean people in neutral cultures are cold or unfeeling, they are simply more careful to monitor the amount of emotion they display. It also doesn't mean that affective cultures do not apply reason, but in their world, passion indicates value.
In addition to Switzerland and the US, communication research has shown that emotional reactions were least acceptable in Japan, Indonesia, the UK, Norway, and the Netherlands - while most accepted in Italy, France, Latin America, and Singapore.
Something to keep in mind the next time you wonder why someone seems to not care... or is behaving "over the top".