If someone provided me with a good researcher, I might undertake to write a book called something like "A Nation of Cowards: Raising Our Children in Fear". It would compare how Americans addressed risk fifty years ago with how we do it today. Of course, research might find some exceptions to the rule -- were we more germ-phobic in the late 1950's than we are today? On the whole, though, I expect one could document that my now-middle-aged generation was expected to accept many more everyday risks without a second thought, and society as a whole was more prepared to undertake risky endeavors (e.g. going to the moon).
But maybe there are several books like this out there already. Names, anyone?