Every Memorial Day reminds me of our big household paradox. My spouse and film production partner, Amy Gerber, is only three years younger than I am, and yet we are a generation apart. How about that for a slice of “This American Life”?

So what’s in a generation?

Social scientists and demographers define a generation as “a group of people living together at the same time” and measure it by its duration—20 to 22 years—when children grow up and have children of their own. By that definition, Amy and I appear to be marching in step, although we had our first child well into our thirties.

Recently, though, after working many years on a film about World War II and the Cold War, we’ve discovered that age isn’t the biggest factor shaping the identity of our generation. Nor are the defining moments we share together, especially in wartime. Sure, those are powerful forces. We acknowledge them this weekend, honoring the American war dead from present-day armed conflicts, honoring all our forebears who ever fought and died in wars leaving families behind, and grieving them in the same breath.

As it turns out, the defining moments that shaped our parents’ generation have just as much (if not more) to do with how we fit into the world around us. Why? Because they stamped our families indelibly, and we grew up with that imprinting. Every generation is just as much a collection of families, by definition, as it is a collection of individuals. What else, besides family, travels with us from cradle to grave?

As Amy and I both know, when a parent experiences war firsthand and relives it with a young child, the child makes sense of a chaotic, frightening and often senseless world by studying and learning how the parent coped with that hardship. These are the lessons the child never unlearns. These are the stories the child never forgets. This is the worldview the child will carry into adulthood.

These are things Amy and I both learned, growing up in households where both our fathers had vivid boyhood memories of starvation and war….only they were boys in different eras, and they were on opposite sides of the same war.

Two dads on opposite sides

My father remembered the Depression. He served in the U.S. Navy during World War II, fighting against Nazi perpetrators. Amy’s father was held hostage in a German POW camp as a boy of six, the son of a Nazi scientist watching Allied “liberators” become perpetrators overnight in the hunt for German assets to be plundered. My father said he nearly died of boredom during his mostly uneventful tour of duty in the Pacific. Amy’s father nearly died of starvation. World War II made a man out of my father. It robbed my father-in-law of his childhood. He had children early; my father waited until he was 40 to have his first child.

What shapes a worldview?

My father was proud of winning a war of battles that he framed as a struggle of freedom against tyranny. He measured himself against his distant grandfather John Hart, who signed the Declaration on July 4, 1776, escaped British occupation of his farm, and lost everything he owned in the fight for independence. To win was to pool common resources, to form the best organization, and to engage the enemy out in the open. Like Cincinnatus, my father went back to his farm and his brewing business after the war, and paid little attention to its aftermath.

When Amy’s grandfather was taken away by US Army intelligence officers in Operation Paperclip, her father saw with his own eyes that the real winner of that war had yet to be declared in 1945. Whoever ended up with the most technology would be the true victor. To win was to sequester resources, to steal secrets and keep them, to work behind closed doors, and to engage the enemy in the shadows. The boy’s first challenge was simply to survive captivity. He was proud of that—proud of his wartime role as an asset to be plundered for the benefit of his new country, the US. He measured himself against his distant grandfather, Goethe, and went on to play his own part in the family tradition that had spawned generations of scientists in his paternal line.

These men had completely different worldviews. We, their daughters, discovered them by asking, “Dad, what are you proudest of? What did you risk in the war? What would you be willing to risk in the future, and why?” As a result of those intimate conversations and early imprinting, Amy and I will always hail from different generations.

Und trübte: our new documentary

The story of what Amy’s German grandfather did in the war; how he was smuggled into the US to continue his top-secret physics work in New Jersey even though he was convicted as a Class II war crimes offender back in Germany; and why her dad ended up in captivity with his mother and siblings, is told in Amy’s fearless documentary film, MY GRANDFATHER WAS A NAZI SCIENTIST: Opa, von Braun and Operation Paperclip, which we produced together. (Amy’s father, a physicist like his father before him, has now spent a lifetime working for the US government as an American citizen.)

We decided to release the film this weekend on DVD because it seemed like the perfect time to intrigue our core audience, made up of the World War II buffs and the Cold War aficionados among the so-called “Greatest Generation.” War was the defining event in the lives of our fathers born on opposite sides, men who raised American daughters the same age of different generations. As parents, Amy and I will spend the rest of our lives bridging that gap to establish our own identity as a German-American family that World War II brought together. Maybe that’s why Amy dedicated her film to our daughter.

Buy the DVD now on Amazon. Follow events on Facebook. Have a great holiday weekend.