A thing to remember in this are the sizes of the various markets.
NYSE, the largest in USA, has a combined market value of 20 trillion dollars, whereas the largest in China (Shanghai Stock Exchange) has a combined market value of 4 trillion. This is for two economies of about the same size.
This means that when the Chinese market drops (or raises) the overall impact for the wealth of the country is much smaller than a similar change would cause in the American markets.