OTOH Dominicans (together with other Latin Americans) are more polite when it comes to greetings and introductions. You say 'saludos' or 'buenas', or 'buen d?a' or 'buenas tardes/noches' to complete strangers, upon entering a lift, a bus, a carro p?blico, a shop - even when passing strangers in the street, in certain circumstances. Do that in any big city in Europe and North America and people think you're on day release from a mental facility.
Then there's the whole 'buen provecho'/'a buen tiempo' rituals - non-existent in English-speaking cultures.
When you arrive at a social gathering, even if there are twenty people present, you are expected to greet every single one individually, even if you don't know them, and introduce yourself - fulana, fulano, encantada, igualmente, un placer... In English-speaking countries at least it's often acceptable enough to wave and greet the group vaguely, ignore the people you've never met until introduced, and home in on the ones you do know.
There may be exceptions, I can't speak for the entire English-speaking world, but this is generally speaking.
So, they don't say please, thank you and sorry as much as Brits and other anglos. We think they're rude, but they also think we're rude when we walk into a restaurant and don't say buen provecho to the strangers who are already eating, or greet the people in the lift or in the bus when we get on.
Then there's the whole 'usted' thing, that also doesn't exist in the English-speaking world, although this is not always polite in a respectful way. It can also be a distancing device, and is sometimes even used in a passive-aggressive way.