Could Jack-O’-Lanterns Work?

Creating Jack-o’-lanterns is part of both Irish and Christian tradition, with the controversial claim that these carved vegetables ward off evil spirits.[1] Such wary evil spirits are supposedly afraid of the scary faces carved into the vegetables (currently pumpkins in the U.S.). The same protective benefit is said to also come dressing up like a ghost for Halloween[2] or having stone gargoyles on the exterior of a building[3], though gargoyles tend to be out all year round. Is there something to the claim of Jack-o’-lanterns providing protection from evil spirits, or are these carved vegetables just fun Halloween decorations?

Where do Jack-o’-lanterns even come from? The origin of the term Jack-o’-lantern itself is somewhat uncertain. On the one hand, the term is said to originally refer to an occasional faint glow seen in bogs in England.[4] On the other hand, the term is said to come from an unsavory character in Irish legend named Jack, who tricked Satan at least once. Upon Jack’s death, he was not welcome in either Heaven or Hell, so his spirit supposedly wanders the Earth. As the story goes, Satan gave Jack a hot coal from Hell to light his way, which Jack placed into a hollowed turnip or rutabaga to serve as his lantern. Somehow it became a traditional part of the Irish festival Samhain, to carve scary faces into turnips (or rutabagas) and light them from the inside with a candle. The purpose of the scary faces carved into the vegetables is to scare away Jack or evil spirits that wander by. Christians reportedly adopted the tradition for All Hallow’s Eve (Halloween). For our purposes, the most important piece of the history is the traditional claim that a Jack-o’-lantern can protect from evil spirits.

While it might be interesting to test this protection claim with the same scientific rigor as (e.g.) testing a new drug, there are unfortunately many unknowns that would make such testing difficult or even impossible. How do we know when an evil spirit is lurking about and causing trouble? Have there actually been any modern credible sightings of evil spirits? How do we know when the absence of unfortunate events is due to the protective power of a Jack-o’-lantern? How can we perform a placebo test – put the Jack-o’-lantern in a closed box? Can evil spirits see through the box? Must the candle be lit? Would using an electric light in place of a candle affect the protection from the Jack-o’-lantern?

Possibly the biggest problem here is the elusive concept of evil spirits, but maybe that concept can be avoided. After all, someone can test-drive a car without knowing technically how it all works. If we assume that evil spirits could potentially be anywhere, then we might very well blame them for any negative event that occurs. Following this reasoning, a simple test would be to see if a Jack-o’-lantern helps avoid negative outcomes. Some of those negative outcomes could be caused by evil spirits – to the extent such things exist. (Keep in mind this is a STEM blog.)

So far we have simplified the task to determining whether a Jack-o’-lantern could protect from negative consequences. While I don’t know of anyone with the resources and inclination to investigate this question in a scientific manner, I’m sure we can speculate. We just need to consider some possible negative outcomes and whether a Jack-o’-lantern might make them less likely. Really we could just consider outcomes that can become less likely when possessing or displaying a Jack-o’-lantern, and technically we need only one such possible outcome.

Jack-o’-lanterns could potentially help avoid negative outcomes involving people with bad intentions. For example suppose some teenagers are interested in vandalizing someone’s house. Before Jack-o’-lanterns became common, a glowing face may have acted as a deterrent. While it may not scare the teenagers themselves these days, it may scare the younger children that the teenagers were asked to look after, by their parents, especially after a scary movie. A lit candle by itself may even deter them, since whoever lit the candle may still be home. In that case, it could even deter burglars from visiting that particular house. In more superstitious times, if either kind of troublemaker carried out their plans and no one saw them, the respective negative outcomes might be attributed to evil spirits. After all, “surely” no one the residents know would cause them such trouble.

It’s also possible that a Jack-o’-lantern may deter troublemakers from nature as well. Suppose someone living in a house has a garden or even a farm with crops that some deer are fond of eating. A glowing Jack-o’-lantern may resemble a predator and discourage the deer from staying very long. After all, resemblance of a predator is a common use of protective coloration in nature. It seems to work well enough for moths with large spots on their wings resembling eyes. So lit Jack-o’-lanterns could act as nighttime scarecrows.

Here are just a few examples of how a Jack-o’-lantern may help protect from negative outcomes. Since I don’t know much about evil spirits, I can’t say for sure that they aren’t the cause of such negative outcomes. If we assume that they are the cause, then, yes, Jack-o’-lanterns could actually work as claimed. Just to be safe, I still lock the doors and windows of my house at night, especially around Halloween. And, yes, I carve a pumpkin into a Jack-o’-Lantern just before Halloween. Don’t underestimate (or tempt) the power of evil spirits, even if they “don’t really exist.”

References

[1] https://www.merriam-webster.com/words-at-play/the-history-of-jack-o-lantern

[2] https://en.wikipedia.org/wiki/Samhain

[3] https://en.wikipedia.org/wiki/Gargoyle

[4] https://en.wikipedia.org/wiki/Jack-o%27-lantern