It’s the most wonderful time of the year, or the worst depending, in part, on whether you’re a fan of Christmas songs. I’ve been keeping my earbuds in when I go to the supermarket to avoid the wave of holiday cheer that is surely blaring from the omnipresent speakers. I’m hardly alone in my vulnerability to these thunderous tunes where snowmen talk and reindeer fly.

Psychologists have found that playing Christmas music too early in the year can wreak havoc on one’s mental health (particularly if they’re constantly exposed to it, as those in certain retail environments may be). And there’s extensive neuropsychological reasoning as to why these carols have such a profound effect on us.

What Happens When We Hear Christmas Music

“Our response to Christmas songs depends on the association,” says Dr. Rhonda Freeman, a clinical neuropsychologist. “Many of us associate this music with childhood and a happy time of presents and traditions and all the specialness that happens around that time of year. When the brain makes these associations with something very positive and pleasurable, the rewards system is being activated [which triggers] a number of chemicals including dopamine.”

There are two sides to the coin, though. Just as our brain can fire up joy in light of a positive association, it can also spark a flood of sadness and anxiety upon a bad one.

“Some people had abusive childhoods, or they experienced a loss of some kind or a person someone passed away,” says Freeman, adding that music in general impacts the amygdala, which unlocks our emotions and reactions to stressors. “The reward system can also be associated with pain. For that population, Christmas songs can be very painful to hear.”

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Freeman’s point about childhood is key. Certainly, we may become sad if we dealt with a difficult time while hearing Christmas music as an adult, but it’s probably more intense for us if we experienced that hardship as kids hearing the music. Why? “Because our prefrontal cortex is less developed when we are children, so we are more emotional beings when we are little. That becomes a part of our memory.”

Certainly this is the case for me. My twin brother died when we were nine years old, exactly one week before Christmas day. But Christmases up until then were always hysterically happy times. This is probably why I feel like I need to protect myself against Christmas music because it could go either way: my brain could take me to one of the buoyant Christmases, or to that very terrible one and the lonely ones that followed. This also explains why, as Freeman points out, it’s important that the listener has control over how and when they hear Christmas music.

Retail Workers’ Brains May Be Working Overtime

“If you don’t want to hear a song, or are hearing it on repeat for three hours [with no say in the matter], your prefrontal cortex is working hard to filter it out so you can focus,” Freeman says, adding that though she’s not familiar with the aforementioned research about Christmas music being harmful when it’s played too early in the year, it makes total sense that anybody forced to hear a song they’re not a fan of on repeat would start to suffer. “Also, environment is everything. If you’re in a store and you don’t want to hear it, that’s stressful because your brain has to work harder to focus.”

Phil Gentry, a musicologist based at the University of Delaware, notes that while there is a strong psychological component to how Christmas music (or perhaps any songs with which we’re very familiar) affect us, it’s important to understand that aside from subject matter and seasonality, this ever-growing batch of songs don’t really have anything in common.

“There's no one secret chord that unlocks it,” Gentry says of the genre. “It’s a very diverse set, with everything from Mariah Carey to Silent Night. What makes it so unusual, at least in the U.S, is that it’s really the only set of songs we hear widely at the same time of year, every year. We don’t really have that with anything else, which is partly why it can make us so nostalgic.”

The Last Remnant Of Oral Tradition

Christmas songs are also formidable because they’re among the last remnants of what used to be common practice among humans: the passing down of an oral tradition.

“You learn it as a child, and it’s one of the few bodies of songs that people have deep inside their memories,” says Gentry. “When I ask my students what are songs you could teach without referencing any [document]? The answer is often a Christmas song.”

Keep in mind also that Western music, as Gentry points out, was “designed to elicit emotional responses.” There are some pretty corny Christmas songs (sorry, Jingle Bells), but even if you hate them, you must admit that songs like Silent Night and Carol of the Bells are ridiculously poignant. Perhaps that’s another reason these tunes can be so maddening: How many times can we feel this intense emotional pressure before we beg for it to stop? Well, we’ve got the whole holiday season to find out.

Holiday Survival Guide

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