[laughing women cornish]Matt Cardy / Getty You might have learned a few local phrases, stashed your ball cap, and congratulated yourself on not sticking out like a sore thumb abroad. But culture goes deeper, and there are a number of customs and gestures that Americans use without thinking twice. When traveling, these customs will not only out you as a tourist, but could get you in hot water in other countries. Inspired by this Quora thread, we’ve rounded up some of the most common things Americans do that are seen as offensive elsewhere. 1. TIPPING [TIPPING CHECK BILL TIP]MATT CARDY / GETTY A contentious issue even here, both over- and undertipping can quickly make you the least popular person at the table. But in Japan and South Korea, tipping is seen as an insult. In those countries, workers feel they are getting paid to do their job, and take pride in doing it well; they don't need an added incentive. 2. SITTING IN THE BACK OF A CAB While it's customary for Americans to hop into the back of a cab, in Australia, New Zealand, parts of Ireland, Scotland, and the Netherlands, it's considered rude not to ride shotgun. Whereas cabbies in the US will sigh and reluctantly move their newspapers and lunches from the front seat, in other countries it's a matter of egalitarianism. 3. THROWING A THUMBS-UP In a lot of countries, especially in the Middle East, Latin America, Western Africa, Russia, and Greece, a thumbs-up basically has the same meaning as holding up a middle finger does for Americans. 4. LAUGHING WITH YOUR MOUTH OPEN In Japan, laughter that exposes your pearly whites is considered horse-like and impolite — sort of like noisy, open-mouthed eating is considered rude to Americans. 5. CALLING THE USA "AMERICA" [american flag]Matt Cardy / GettyIn South America, claiming you're from America, rather than the United States, is seen as being politically incorrect, as it implies that only the US should be considered America, and that South America is unworthy of the title. 6. BEING FASHIONABLY LATE Americans often make appointments for "around x" or "x-ish." Being a few minutes late, or, as we even call it, "fashionably" late, is standard to Americans, but unacceptable in many other countries (like Germany) where leaving people waiting is taken as you thinking your time is more valuable than everyone else's. 7. BEING ON TIME On the other hand, many Latin American cultures, notably Argentina, would consider it bad form if you showed up to a dinner party right on time, akin to someone arriving an hour early in America. 8. HAVING ONE HAND IN YOUR POCKET This is considered arrogant in Turkey, as well as some Asian countries, like South Korea. 9. USING YOUR LEFT HAND FOR ANYTHING Not all cultures have or use toilet paper, and tend to use their left hand in lieu of it. Accepting gifts, eating, or doing pretty much anything with your left hand in much of Africa, India, Sri Lanka and the Middle East is like a (disgusting) slap in the face. 10. OPENING A PRESENT IMMEDIATELY [WRAPPING GIFTS PRESENTS]MATT CARDY / GETTY In most Asian countries, most notably China and India, tearing into a gift in front of the gift giver is poor form. It looks greedy. 11. WEARING SWEATPANTS, FLIP FLOPS, WRINKLY CLOTHING, OR BASEBALL CAPS IN PUBLIC Sure "athleisure" (stylish sportswear worn outside of the gym) is a hot new trend stateside, but in most countries, notably Japan and most of Europe, this sort of sloppy appearance is considered disrespectful. 12. ALTERING YOUR MEAL In foodie cultures like France, Italy, Spain, and Japan, asking for ketchup, hot sauce, soy sauce, or salt to alter your meal may raise some eyebrows. Before you ask for a condiment, see if there are any on the tables — if not, you should probably refrain. 13. SHOWING THE SOLES OF YOUR FEET In many Arab, Muslim, Hindu, and Buddhist countries, showing the soles of your feet is a sign of disrespect, as they're considered the lowest and dirtiest part of the body, since they touch the dirty ground. Men should cross their legs with caution. 14. KEEPING YOUR SHOES ON While you probably think you're doing the world a favor by keeping your socks under wraps, in most Asian and Caribbean cultures it is expected that you take your shoes off when entering someone’s home. 15. DRINKING SOMEONE ELSE'S ALCOHOL [party drunk binge drinking alcohol shots]Matt Cardy / GettyApparently, it's rude to drink alcohol you didn't personally bring to a party in Norway. In the US, on the other hand, bringing a six pack of beer to a BBQ allows you access to anything else at the event. 16. MEN SHOWING SOME SKIN It's rare to see topless men in South Korea, where men even keep their shirts on at the beach. 17. EATING ANYWHERE THAT DOESN'T SERVE FOOD In Rwanda and Japan, it is considered rude to eat anywhere that isn't a restaurant, bar, or hotel. Eating a banana on the bus? Ice cream outside? All no-nos. 18. TELLING PEOPLE TO HELP THEMSELVES While you think you're being a host extraordinaire by opening up your home to someone and essentially telling them to feel right at home, in some cultures (like in Asia) this hands-off approach is uncomfortable. To them, hosting guests is a little more involved. 19. TOUCHING Americans are notoriously friendly, but hugging and touching others, even if only on the arm, is offensive in places like China, Thailand, Korea, and the Middle East. Respect that personal space varies from country to country. 20. KEEPING YOUR CLOTHES ON IN SAUNAS AND STEAM ROOMS [Sauna]Matt Cardy / GettyWhile not offensive per se, people from Scandinavian countries and Turkey will think you're prude if you keep your clothes on in saunas, spas, and steam rooms. 21. ASKING CERTAIN QUESTIONS Asking "what do you do" is a common American icebreaker, but is often considered insulting, especially in countries with social-welfare systems, like the Netherlands, where people feel that it's a way of pigeonholing them, and of being classist. You might as well just ask someone you just met what their salary is. 22. REFUSING FOOD Americans often refuse food to make it easier for their hosts, but in most Arab countries, like Lebanon, it is considered incredibly rude to reject anything offered, especially food. 23. NOT DECLINING GIFTS Americans are quick to accept gifts, favors, and invitations, and often without offering something in return. However, many cultures (like in Japan) expect you to decline things a few times before ultimately accepting them. In China, you're even expected to refuse a gift three times before accepting it. 24. POLISHING OFF YOUR MEAL To Americans, finishing a meal shows the host how much they enjoyed the meal. In other countries, like China, the Philippines, Thailand, and Russia, it signifies that you're still hungry and that they failed to provide you with enough food. 25. BLOWING YOUR NOSE In countries like China, France, Japan, Saudi Arabia, and Turkey, blowing your nose in public is not only rude, but considered repulsive. NOW WATCH: 8 travel hacks even frequent fliers don't know