Modern American children have become so disconnected from the source of their food that many kindergarteners think bacon comes from a plant, not a pig, according to a small new survey.

This fundamental misunderstanding also seems to extend to cheese, hot dogs, chicken nuggets, shrimp, and hamburgers, all of which were deemed to be plant-based by a significant number of kids surveyed.

Testing 176 children in the United States between the ages of 4 and 7, researchers found "pervasive errors in their basic food knowledge".

Meat was the most misunderstood, but some vegetables, like deep-fried potatoes, also caused confusion. In the end, nearly half the group sorted french fries into the 'animal-based' category, while about 41 percent placed bacon in the 'vegetable-based' category.

"One reason that children may lack basic food knowledge is because so many of them have very little exposure to how food is grown," the authors suggest.

"With fewer and older Americans farming, the number of children in the United States who live on working farms has dwindled."

At the same time, meat consumption in the US has hit an all-time high, with the average person consuming more than 200 pounds of poultry and red meat in 2018.

Compared to research on a child's understanding of food nutrition, surprisingly little has been done to test their understanding of where food actually originates. Indeed, some past research has indicated young kids have a limited grasp on food production, especially for foods that look quite different from their original ingredients.

In 2014, for instance, a large national survey in the United Kingdom found a third of kids aged 5 to 8 did not know how bread, cheese, or pasta were made.

But there's another explanation, too. Parents might be reluctant to honestly tell their children how animal products get on their plates.

"Parents may deliberately withhold information about animal slaughter in an attempt to safeguard children's innocence," the authors of the current study explain "viewing the realities of meat production as too gruesome for children to know at a young age."

Telling a child, for example, that a hamburger comes from a cow is an elusive way to impart information. A kid might think a cow makes hamburgers like a tree makes apples, the authors say. Even when a kid hears that milk comes from cows, they might not understand how.

That might sound ridiculous to an adult, but a 2003 study interviewed kindergarteners about their food and found that many did not realize meat was the flesh of dead animals. Some kids that did know this thought the flesh was harvested from animals that died of natural causes.

"Together, these results indicate that meat may comprise a unique gap in children's food knowledge," the authors write.

"Failing to understand the link between animals and meat may support early dietary preferences that have grave environmental impacts, particularly as they become resistant to change later in life."

When researchers conducted the same surveys among 78 kids between the ages of 6 and 7, they found these slightly older kids were much better at categorizing food items into 'animal-based' or 'plant-based' than the 4- to 5-year-olds.

This suggests a child's food knowledge takes a considerable step forward between the ages of 4 and 7, and yet even older kids still do not appear to fully understand the idea of animals as edible food.

When all the children in the survey were asked to classify foods as either "OK to eat" or "not OK to eat", two-thirds of the younger group incorrectly classified a cow and pig as "not OK to eat". The kids may not realize that beef and pork, respectively, come from those animals.

Researchers suspect young humans start out placing a high value on mammal lives, but as they grow up, those values begin to decline in favor of food.

So if we can figure out how to honestly convey food in ethical and environmental terms to children, we could change how they eat for the rest of their lives.

This is important, as replacing meat is one of the most powerful ways an individual can reduce their carbon footprint.

For kids to understand that, however, they need to know where their food is coming from. And in that department, it seems we have a lot of room for improvement.

The study was published in the Journal of Environmental Psychology.