Dr Michael O'Neill (2010) parses US society into five distinct generational cohorts based on differing beliefs and values as follows:
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Note that Baby-Boomers are divided into two sub-cohorts: Traditionals (born 1945-1954), and Generation Jones (born 1955-1964). This attitudinal break within the ranks of baby-boomers has major implications for generational marketing and politics in the US. Follow the link below to read the entire report.
Source: O'Neill, M (2010), Generational Preferences: A Glimpse into the Future Office, Knoll.