As divisive as Miley Cyrus may be, the small tattoo on the back of her arm is of a subject even more so: Vegemite. While it's unconfirmed whether or not the American pop star is a fan of Australia's beloved sticky-brown condiment, her beau Liam Hemsworth is quoted in Australia's Sunday Style saying that he lived on "after-school Milo and Vegemite on toast" as a kid, and his nostalgic admiration of it is unsurprising. He's Australian, and Australia notoriously loves the pungent paste smeared on buttered toast. What would be surprising, though, is if Miley loved it, because to be born outside of Australia and have a voracious appetite for the condiment is rare.

"Vegemite may be the best predictor of national identity of any food in the world," Kay Richardson writes in Gastronomica. "That is, if you eat Vegemite, you are almost certainly Australian."

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Originally labeled "Pure Vegetable Extract," Vegemite was born in a Melbourne laboratory in 1922 out of necessity. World War I had just ended, disrupting the global trade market and causing a panic in Australia; the continent had developed a taste for Marmite, Britain's yeasty paste with the slogan "Love it or hate it," since it had landed on their shores in 1908, and they no longer had access to it. To alleviate the imbalance between supply and demand, Fred Walker, an entrepreneur involved in Australia's food industry, tasked scientist Dr. Cyril P. Callister of Fred Walker Company to concoct a replacement. Using brewer's yeast, celery, onion, salt, and some top-secret ingredients, the cultural food icon was born.

But by the time the product hit the markets in the summer of 1923, Marmite had once again become available, making Vegemite obsolete. Desperate to increase their sales, Fred Walker Company temporarily changed the name of the product to "Parwill" as an attempt at rebranding, which did not work. However, in 1939, the product was graced with the one thing that typically ensures an immediate increase in demand: medical endorsement. Advertisements touting its high concentration of B vitamins appeared in the British Medical Journal, and, during World War II, the paste became a staple in soldiers' rations packets and cupboards back home. Today, the Vegemite sits in nine out of every 10 pantries in Australia. Most commonly eaten on toast with butter or margarine, the salty, bitter paste can be eaten at any time of the day.

Image by Janeen via Flickr

But how did such a beloved product completely fail to find a market outside Australia? According to What's Cooking America, 22 million jars of Vegemite are produced every year, but only a mere three percent of them are shipped outside the continent. And it's not just that non-Aussies don't have a taste for it—it's that they hate it. In a Youtube video with nearly seven million views_,_ American kids try the paste for the first time, making quick comparisons to poop and alleging that the paste "makes you want to barf." Vegemite tops American lists on disgusting foods you find abroad. Even President Obama thinks it's "horrible."

Like the best of intense adulthood obsessions and repulsions, it turns out the source of your love or hatred of the condiment likely begins with your parents. Alison K. Ventura, Ph.D., a professor at California Polytechnic State University who has researched and written about how children develop food preferences, traces your sentiments about Vegemite all the way back to before your first breath.

Though you're not conscious of it, you start forming your food preferences in utero, mostly thanks to your mother's diet. In short, the flavors your mom tastes in her mouth when pregnant with you get passed to you through her amniotic fluids. If breastfed, you'll develop those preferences even more through her breastmilk.

"With cultural foods like Vegemite that a mother eats often when she's pregnant and breastfeeding, the baby forms a familiarity with the flavor," Ventura says. And while newborns are born with strong negative reactions to bitterness, which is present in the Vegemite, introducing the spread with toast can help young children acclimate themselves to the flavor. It's called associative conditioning—pairing something familiar and generally liked, such as bread, with something more unfamiliar.