Here's what got me thinking about this: Barack & Michelle Obama. Whatever your political leanings are, you have to admit that this couple does not represent the Babyboomer generation like the Clintons or the Bushs. Yet they were born in 1961 and 1964, respectively, officially making them Boomers.
The thing about generations is that the lines are drawn based on birth rates. And yet birth rates do not affect the way we are as adults as much as formative cohort experiences - what was happening when we were coming of age. Going to college in the 1980s (like the Obamas) was not all that different than finishing up in the 1990s (like me). Sure there were differences, but not as drastically as the difference of finishing up college in the 1960s.
Even now, I look at someone who is going into her senior year of high school and think, "How different is her experience from mine 20 years ago?" Not nearly as different than the experience my parents had versus what I had. I remember looking back at photos of my parents when they were in high school - always black and white film, always looking like they were from another planet. I look back at my high school snap shots and it's not the same. Sure we had stupid haircuts, but it wasn't like girls weren't allowed to wear pants to school - or boys had strick rules regarding hair length.
Even looking to the entertainment industry: Gidget (Sally Field) versus Molly Ringwald versus Miley Cyrus. Molly and Miley as teens are equally worldly. Not so much with Gidge.
Which brings me back to the Obamas. What do you think - Boomer or Xer? Is it the year they were born - or the years they came of age - that determined their generational characteristics?