“Christmas Shoes,” the holiday dirge about a kid buying a pair of sweet kicks for his dying mom, still gets airtime each December. Ditto the Elvis classic “Blue Christmas” and Joni Mitchell’s unusually miserable even for Joni Mitchell “River.” Though another notable seasonal tune argues that it “‘tis the season to be jolly,” that doesn’t always seem the case. Sad Christmas music is inevitable because, it turns out, humans aren’t great at pure positivity.

Over the years, scientists attempting to explain our apparent emotional masochism, like USC’s Matthew Sachs, Ph.D., have hit on a crucial point: Sometimes, experiencing sadness just feels good. “It’s generally accepted that there are several reasons why sadness, when expressed through art, can be enjoyable,” he told Inverse. “If you’re the kind of person who listens to sad music during the holidays, you’re more likely to be an empathic person, but more generally you get some kind of psychological benefit from sadness.”

According to Sachs, who authored a paper on the pleasures of sad music earlier this year, mixed emotions are a hallmark of Hallmark season — the end of year prompts reflection, nostalgia, and, for some, seasonal affective disorder — and sad music could be used as a tool for dealing with these issues. Whereas “Rudolph the Red-Nosed Reindeer” asks us to sweep unpleasantness under a rug and buy into the existence of a physiologically improbable Caribou, “Fairytale of New York” deflates the holiday a bit so we can get our hands around it.

Broadly speaking, says Sachs, sad holiday music offers two strategies for dealing with negative emotions. “One would be to purge yourself to move past them or get rid of them,” he says. “The other would be to strengthen them and go more deeply into them.”

This is where personality differences come into play. When conducting his studies, Sachs finds it helpful to ask participants one question: When you’re feeling sad, do you want to feel better immediately, or is it okay to prolong your sadness a little bit? People who take the former approach might listen to a song like Taylor Swift’s “Christmases When You Were Mine” as a means for Aristotelian catharsis — that is, an emotional purge. Others, going all in, might find more psychological value in allowing themselves to revel in Tay’s heavy-handed misery (“When you were putting up the lights this year, did you notice one less pair of hands?”).

Of course, when it comes to something as complicated as human emotion, to think in binaries is to massively oversimplify. Sachs admits there are multiple other theories that attempt to explain how we derive pleasure from sad music: Some researchers suggest that it encourages us to address whatever caused the sadness in the first place, which feels good in the long run. Others think it’s enjoyable because we can differentiate between the sadness we perceive and feel. Still others think it feels good to be reassured we can feel anything at all.

Holiday emotions are as difficult to avoid as the family and friends that cause them. Mitigation is a much more productive strategy. The fact that sad music can trigger emotional responses that happy music can’t, says Sachs, is valuable in itself. Even though he doesn’t do Christmas, he can’t deny that he takes pleasure in the poignant beauty of the melancholy Peanuts classic “Christmastime is Here.”

“I’m Jewish,” he laughs. “But I’m almost lamenting the fact that I’m not celebrating it.”