General Social survey respondents have been asked the following question each survey year since 1972: "Generally speaking, would you say that most people can be trusted or that you can't be too careful in life?"
The graph shows that trust among Americans has been slipping for four decades (sample size = 34,790). The red section shows the percent who say that people can be trusted: this has dropped from around 50 percent in the early 70s to less than 40 percent currently. The trend has paralleled the post-1965 ethnic diversification of the country.
Falling trust is not a good sign since a flourishing society depends on a certain amount of confidence that contracts can be made and will be honored.
I'm putting together a cross-national data set and plan to identify the social correlates of ethnic diversity. I predict the results will not be pretty.
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be." ~ Lord Kelvin