Strauss–Howe generational theory

The Strauss–Howe generational theory, devised by William Strauss and Neil Howe, describes a theorized recurring generation cycle in American and Western history in which historical events are associated with recurring generational personas called archetypes. Each generational persona unleashes a new era (called a "turning") lasting around 21 years, in which a new social, political, and economic climate ("mood") exists. They are part of a larger cyclical "saeculum", a long human life, which usually spans around 85 years, although some saecula have lasted longer.

The theory states that a crisis recurs in American history after every saeculum, which is followed by a recovery ("high"). During this recovery, institutions and communitarian values are strong. Ultimately, succeeding generational archetypes attack and weaken institutions in the name of autonomy and individualism, which eventually creates a tumultuous political environment that ripens conditions for another crisis.

Academic response to the theory has been mixed, with some applauding Strauss and Howe for their "bold and imaginative thesis", while others have criticized the theory as being overly deterministic, unfalsifiable, and unsupported by rigorous evidence. The theory has been influential in the fields of generational studies, marketing, and business management literature. However, the theory has also been described by some historians and journalists as pseudoscientific, "kooky", and "an elaborate historical horoscope that will never withstand scholarly scrutiny". Academic criticism has focused on the lack of rigorous empirical evidence for their claims, as well as the authors' view that generational groupings are more powerful than other social groupings, such as economic class, race, ethnicity, sex, religion, culture, and political affiliation.