Why should generations be interesting? There are two questions here, because generations have two kinds of interest. They have historical interest: a succession of generations from Lost to Greatest to Silent to Boomer to X to Millennial. And they have personal interest: the generation in the first person, what separates us from our parents and divides us from our children – “my generation,” “our generation.”

As a unit of historical analysis the generation is worse than useless. The biologist’s refutation of race applies: since variability within a generation equals or exceeds the variation supposed to divide generations, generations are supposititious.

Of course generations really are different. Every generation has its own distinctive patterns of behavior – but distinctive is not the same as characteristic. Nothing is more distinctive of a generation than its common names – but, remember, the fact that some names are common does not mean that most people have common names.

The generation is unreal, but unreal is not absurd; unreal things can exist formally, like lines on a map. The generation is likewise formal: consensual, not demonstrable. But why this consensus?

It is a pleasure to be sorted into a particular generation because being sorted, if it is not discriminatory, is inherently pleasant. Advertisers know this. They know that offering to tell “Which X are you?” or “What kind of X are you?” tempts you, for all x.

And something loves to displace the faults of human nature to contingent aspects of it. Sentences that begin by naming “these days”, “this country”, or “our society,” generally become intelligible only once they are universalized, and referred to human beings as such. The generation provides another means for such displacements. Then such awful questions as “Why are we here?” can be rephrased in cozier terms like “My generation has no sense of purpose.”

What is it that we share when we share a generation?

Sharing a generation is the least two people can have in common (who have anything in common at all): thus we are most attached to our generation when we have few other attachments. Those who have something more definite to be loyal to – nation, religion, community, cause – they would never number their generation among the things that define them. And, inversely, those who expect their generation to define them tend to lack particular loyalties.

Sharing a generation is the weakest hold two people can have on each other, who have any hold on each other at all. It is because it is so weak that is so hard to shake off. Say: my generation is my blind spot. I think there is nothing so utterly mysterious to me as my own generation. Because I must draw lovers and friends from it, I want to believe it is better than it is, and when it disappoints me, I see mystery rather than accepting the fact of disappointment.

If it is to take hold at all, generational solidarity takes hold in childhood. Sometimes I would have to explain and defend to adults the things that I and my friends did – defend them to members of other generations. At these times I did not feel as if I were speaking for myself: I felt like an ambassador, charged with a heavy responsibility and answerable to my peers. Suddenly I was not only included, but important. Under threat of scorn from another generation people who would not otherwise speak to me leaped to my defense; people who hardly spoke at all surprised me with the capacity to form complete, reasonable, and persuasive sentences on my behalf.

To embrace the undemanding solidarity of the generation, to build life and work around this experience of inclusion and importance, is understandable. We writers are most susceptible. The generation is our fallback – once we have, for fear of prejudice, abstained from everything else. The temptation is always present: why speak for yourself, when you can speak for your generation? Why stand alone, when you can recruit their implicit support behind everything you say, or make, or do? Why be objective when at last, after everything, you could have them all on your side?