How do you feel when you hear Christmas music? Joyful and happy? Or so frustrated at the looming holiday season that you want to scream?
Here's some scientific reasons why you might be inclined to crack out the Michael Bublé as early as November 1 or bah humbug any hint of a jingle bell.
Stop me if you've heard this one before
Dr Amanda Krause is a senior psychology lecturer at Queensland's James Cook University.
She says Christmas music can feel unavoidable because it is, by nature, cyclical. Like clockwork, as Christmas trees begin to fill stores, carols and contemporary Christmas tunes fill our ears.
Since 2004, when Google started collecting data, Mariah Carey's All I Want For Christmas Is You has seen a massive spike in searches every year in December.
The returning nature of the tune is in juxtaposition to the fact that it really only gets played — albeit quite a lot — during one or two months a year.
This kind of short-but-intense period of listening could affect how much we enjoy Christmas music.
According to Dr Krause, when considering music, in terms of how much we do or don't like it, it's helpful to imagine it in the shape of an upside down U.
"The theory relates to how complex a song is and how much we like it," Dr Krause says.
"Something that's really simple, we don't like very much. It's at the bottom. Something that's very complex and hard to understand is at the other bottom of the U and we don't like it.
"But something that's moderately complex is at that sweet spot at the top."
However, where a song sits on the upside down U is not static: it's consistently changing. Which is where Mariah's annual Christmas invasion comes in.
"If you take Mariah Carey's Christmas song, you've heard it a million times, you know it inside and out, maybe, it's tipping towards the end of it's not very complex because you know it so well," Dr Krause says.
"But the same thing could be true of: 'Oh, it's been a year since we heard this and it's so nice to hear it again'."
The power of nostalgia
According to Dr Krause, one of the most powerful aspects of listening to music is the associations that we make.
"Beyond the notes and the melodies are the memories that we attach to them and those can be quite individual," Dr Krause says.
It's partly because listening to music stimulates almost every part of your brain's limbic system, the set of structures that control emotion, arousal and memory.
"Those memories are quite long-lasting and that's what gives music the ability to prompt memories, and nostalgia is a big part of that."
Dr Krause says research shows that you're most "open-eared" — or receptive — to music in your adolescence and early adulthood.
So, if you spent this time creating warm memories while listening to Jingle Bell Rock, there's a good chance you'll enjoy the song in the future.
"When we're much older, later in life, music from that time period prompts a lot of memories and nostalgia," Dr Krause says.
"It's why there's a strong lane of music therapy dedicated to help people with dementia by using music to trigger movement and memory."
However, the memories we attach to certain music are not always good ones.
For example, if your Christmases have all been disasters, set to a backdrop of Wham, it's possible that when you turn on Last Christmas, bad memories can be triggered, even if you're not upset in the moment.
"Sound is an extremely powerful trigger for memories but they're not all good memories. So we have to take care and think about people's preferences," Dr Krause says.
Your body on music
It's not just your brain that's lighting up when you listen to carols.
Music also triggers physical responses in your body, too, according to Dr Sandra Garrido, a senior psychology lecturer at the MARCS institute for brain, behaviour and development at Western Sydney University.
And, like the double-edged sword of nostalgia, these physical responses have the ability to both soothe and to irritate.
"Everyone has an optimal level of stimulation, when you're feeling under-stimulated and bored, that's not a pleasant feeling," Dr Garrido says.
"When you're feeling over-stimulated, that's not pleasant either."
Dr Gurrido points to studies that have shown that certain types of beats in music can increase heart rate and breathing.
"Music, because it influences our physiological systems, which are related to our alert and arousal levels, it can put us over our level of optimal stimulation," Dr Garrido says.
"If you're busy running around doing Christmas shopping, you've got to pick up the kids, you've got a deadline at work and you're hearing Jingle Bells, Jingle Bells, over and over again, that might put you in a position where your brain can't cope with the stimulation."
