Why do we need to identify "generations"?

There were three articles in today’s Washington Post that talk about the millennials. I am really getting tired of hearing about them every time I turn around.

  • Luxury car companies are manufacturing lower-end models to attract millennials, who apparently want the cachet of the nameplate without spending the big bucks

  • There is a resurgence of traditional horror movies, in part fueled by the tastes of millennials

  • Millennials report high rates of satisfaction with government jobs, but leave those jobs after an average of just 3.8 years.

I think it makes sense to talk about an age group as a demographic: Those who are 18-25, or 25-25, at this moment. Because those groups tend to have certain behaviors in common regardless of what year they were born. But I don’t think it makes sense to talk about a group of people born between two arbitrary years as they march through life as though they were in lock step.

There are a couple of exceptions that I do think make a difference, which are people who lived through some traumatizing event or era:

People who grew up (ages 5-20) in the Great Depression. These people tend to have a set of values and sense of frugality that were burned in and persisted into good economic times
People who fought in WWII (or were the same age as those fighting)
[The two above encompass a big overlap]
Anyone who was old enough on September 11, 2001, to understand the enormity of the event

Otherwise I think there are just too many generalities.