China is a very diverse place with large variations in culture, language, customs and economic levels. Indeed, it has 56 officially recognized ethnic nationalities, 55 of which enjoy affirmative action for admission to university, exemption from the one-child policy and other benefits. The economic landscape is particularly diverse, although only 10% of all land is arable. The major cities such as Beijing, Guangzhou, Hong Kong and Shanghai are rich and modern. However, more than half the population, some 800 million rural residents, still farm with manual labor or draft animals. The government estimates for 2005 report 90 million living on under ¥924 (US$112) a year; 26 million were under the official poverty line, ¥668 (US$81) a year; the poorest are well below that. 
The cultural landscape is unsurprisingly very diverse given the sheer size of the country. Of the 56 ethnic groups recognized by the PRC government, the Han Chinese comprise about 91.5% of the population, although the Han are far from homogeneous and speak a wide variety of local dialects, with customs and divinities specific to individual villages. Indeed even the lunar new year and other nationwide festivals are celebrated in drastically different ways in different parts of the country. After the Han, the Zhuang, Manchu, Hui and Miao round out the top five. Other notable ethnic minorities include: Koreans, Tibetans, Mongols, Uyghurs and Russians. In fact, China is home to the largest Korean population outside Korea and is also home to more ethnic Mongols than Mongolia. Some foreigners find certain Chinese manners to be unrefined, coarse or inappropriate. However, these behaviors are usually benign in nature. The lesson is this: keep an open mind; if you do this, you'll find that people tend to be warm and friendly. Besides, they think as much of some of your behavior.
- Spitting: in the street, shops, supermarkets, hotel lobbies, hallways, or even in restaurants, on buses and in hospitals. Traditional Chinese medical thought believes that it is unhealthy to swallow phlegm. This has declined dramatically since the SARS epidemic of 2002.
- Anyone who does not look Chinese will find that catcalls of "hello" or "laowai" are common: lǎowài (老外) literally means "old (and thus respected) outsider", a colloquial term for "foreigner"; the more formal term is wàiguórén (外国人). Calls of "laowai" are ubiquitous outside of the big cities (and even there, occasionally); these calls will come from just about anyone, of any age, and are even more likely from the very young and can occur many times in any given day. They just should not in any way be considered aggressive and if anything reflect excitement or respect on the part of the Chinese at your presence!
- Staring: This is common through most of the country. The staring usually originates out of sheer curiosity, almost never out of hostility. In certain situations (e.g., on the train), the person may be hoping you'll acknowledge them and start a chat. Of course this is difficult for those who don't speak Chinese. Non-Caucasian people may be treated or seen in a different regard in rural areas.
- Loud conversations, discussions or public arguments: These are very common and sometimes take place at inappropriate times and/or at inappropriate places. Full-blown fights involving physical violence are less common but do occur. Domestic violence can be an issue in public. If you witness such an event, leave the vicinity, do not get involved or look for help. Speaking on the mobile phone can be at very loud levels in public.
- Pushing, shoving and/or jumping queues: This often occurs anywhere where there are queues, (or a lack of), particularly at train stations.
- General disregard of "No Smoking" signs and road signs, Around 60% of adult males smoke.
- Dangerous Driving: Given the high proportion of relatively inexperienced drivers on the roads today, China leads the world in traffic accidents. Be careful!
Some long-time residents say it's getting worse, others say the opposite. The cause is usually attributed to the thousands of new migrants from the countryside who are unused to city life. Some department stores put attendants at the foot of each escalator to keep folks from stopping to have a look-see as soon as they alight - when the escalator behind them is fully packed. In the same department store, others gape at that row of magic steel doors that open and close - and every time they open, it's never the same people.
On the whole, however, the Chinese love a good laugh and because there are so many ethnic groups, they are used to different ways of doing things and are quite okay with that. They are often very used to sign language and quick to see a non-verbal joke or pun wherever they can spot one. (A laugh doesn't necessarily mean scorn, just amusement.) If you have children, bring them! 