Americans have a morbid familial and culinary fascination with foods that defy gravity and good taste during the holiday season: Fruitcake, Oreo Salad, 7 Up Salad, Ambrosia, Hanukkah Jell Rings.

In my family it was ambrosia — which should not be confused with "the food of the gods," from ancient Greek for which it was named. Considered a Southern holiday staple, I always watched as cans of Mandarin oranges and pineapples, huge bags of marshmallows and boxes of gelatin were combined in a bowl with drops of food coloring to make our holiday table complete. But, though my family was supposedly dedicated to not wasting food, I must admit that I never really saw anyone eat it.

One of the things you'll often hear about these holiday staples-from-a-can — with the possible exception of the ever-so-slightly more natural green bean casserole, comprised of canned cream of mushroom soup, frozen beans and topped with prepackaged fried onions— is that people don't eat them as much as they display them. They are, at their best, gelatin-based delicacies that twerk for your viewing pleasure more then your gastronomical delight.

Is it a salad, a dessert or both? KabordaM / Getty Images/iStockphoto

The key ingredients in most gross American holiday foods are gelatin and canned fruit. In her excellent 1986 work, "Perfection Salad," Laura Shapiro uses the eponymous recipe as a means to view the 20th century set foods that put science and convenience at the fingertips of homemakers. Colorful and chemically wondrous, the new foods were aesthetically pleasing (if deliberately bland) and, unlike the foods of the past, they were easy to make — a few bowls, and busy wives were done.

And with each dish, as Shapiro noted, you could tweak things to make it a part of you. Recipe cards and contests immortalized home cooks with their favorite dishes, either in their communities or in magazines aimed at increasingly literate women.

Scientific-inspired cooking only became more endemic in the post-war era, as gelatin became more widely and cheaply available and convenience foods became a way of life. Take the aforementioned 7-Up Salad — a green nightmare in which mayonnaise, marshmallows, gelatin and soda pop met maraschino cherries, cookies and non dairy whipped topping — to see how a popular dessert qualified as a "salad" because of the inclusion of "fruit" (and then it's not terribly hard to imagine why, in the early 1980s, someone thought ketchup should count as a vegetable in school lunches).

This is not actually delicious. Brian Hagiwara / Getty Images

But don't strictly chalk our jiggly table decorations up to the 50s and 60s; the problem isn't a collective desire for the delights of the nuclear age. We pretend to collectively need dishes like green bean casserole (and nobody needs green bean casserole) because we are trying to feed two things deep inside us — nostalgia and memory — that have many recipes.

We long for recipes with names and stories, relics that look like meals that delighted us as children, dishes with sights and smells that remind us where we are, when it is and who we come from. Besides it's not just any 7-Up Salad, it's Aunt Sylvia's world-famous 7-Up Salad (and it's "world famous" because it won a potluck prize in 1962).

The original. Envision / Getty Images

In reality, we claim that these mostly modern dishes are nostalgic because the majority of us have no living memory of the foods of the colonists, pioneers, enslaved or indigenous people that preceded us, let alone from earlier waves of immigration. The food we claim to need to eat on holidays might well have its roots in tradition, heirloom and historic foodways. However, for most of us, what we think of as "traditional" holiday foods are the ones passed down in written form by our grandmothers and great-grandmothers in the last 100 years, rather than orally, from one generation to the next, as they were for hundreds of years before .

Our holiday foods changed when how we cooked changed, and they will change again as our children and their children seek to recreate the memories of our own tables. Get ready for Sriracha green beans or kimchi latkes, or "perfection salad 3.0" with chipotle (but sans aspic) or festive sushi.

In food, the beat goes on. It's always gotta have something to twerk to.