What is it about Chinese society that makes you say that? Not having a go here, I legitimately know nothing about it. If stranger-trust is so low, what societal branches does trust hang on? Is it family, business, political, local..? Is it mediated through technology like WeChat?
There were a lot of reports in the Chinese news a while ago about people being taken in by scammers that pretended to be injured, had the mark help them, and then claimed that the mark's help proved they had a guilty conscious and was responsible and owed them monetary reparations.
This sort of came to a head when a small child was run over and many pedestrians passed without helping.