Here is a good summary of Generations: The History of American's Future, 1589 to 2069, which I read 10-15 years ago. The authors' historiographic technique consists of after-the-fact generalizations that lead them to conclude that there are four basic generational personalities, which occur in repetitive cycles. It is those cycles that dictate the course of American history -- according to the authors.
The generational analysis is of dubious value, because of its reductionism. Human nature and history just aren't that simple. But the analysis does provide a hook on which to hang a neat summary of American history. The book is worth reading for its unique perspective on that history, not for its pseudo-scientific explanation of it.