history. However, in China, many of these have been instituionalized. For example, you must specify your age and have a photograph on your resume. Some jobs even specify the age limit above which you cannot apply, and it's not obvious at all age would make any difference on such jobs. These are just small examples, and there are many more that are both implicit and explicit.
In China, thousands of years of hierarchy lead to a culture of worshiping power and wealth. Stepping on the less fortunate is a cultural practice and national pasttime, as 魯迅 so adeptly poited out nearly a centry ago. Disrimination is deeply ingrained and reinforced by these practices.