In the US, in many places, it’s perfectly acceptable to entirely ignore the strangers going about their business around you. Take the hustle and bustle in NYC and other major cities.
If you greeted everyone who walked past you, you’d lose your voice. But in some places, including France, it can be seen as rude to not say “hello” to someone when they’re in your vicinity. A quick, “bonjour,” will do the trick.
Smiling at strangers may be customary, and the polite thing to do in many circumstances in the US, but the same can’t be said about a lot of other countries. In fact, it can be very off-putting and considered rude. In Russia, smiling in public makes you appear foolish or worse like you’re a sneaky person.
Smiles are reserved for intimate moments between friends and family, and smiling at strangers, as often done in the US, is seen as phony and insincere – and a lot of times, they definitely are.
Finishing Your Plate
In many places in the world, including some cultures in the US, not finishing your plate can be rude. After all, many cooks want to know that you’ve enjoyed their food so much, you ate every bite. But in some other countries, the opposite can be true. Take China, for example.
If you find yourself eating in a Chinese restaurant, or with the locals, and you finish all of the food on your plate, they will take it as a sign that you’re still hungry, which can be seen as offensive.
While it can be seen as rude to refuse a gift you’re given in the US, the opposite can be said of some other cultures. Just as in many Asian cultures where it’s seen as rude to open gifts in front of those who’ve gifted them to you, it can be seen as rude to even accept them in the first place.
You may be coined as greedy if you’re quick to take it off the giver’s hands. Many times, it's also seen as offensive to hastily rip off the wrapping paper instead of taking time and care.
Talking About Careers
Just like in many cultures, it’s rude to simply walk up to a stranger and spark up a conversation, it’s rude to ask someone about what they do for a living. It’s taboo in a lot of countries, including the Netherlands, where it will make you appear like a classist to locals. If you do find yourself having an ice-breaking conversation with a stranger, avoid any job talk.
It can also be seen as offensive, especially in Arab countries, to ask your male colleagues about their wives.