Punch in “Christmas song” and “earworm” into a search engine and you’ll probably be unsurprised by the results.

Mariah Carey, WHAM!, Jingle Bell Rock – these are the true enemies of retail workers across the world at this time of year.

Hear it once, and they just seem to get stuck in your head.

Why? Have our brains rewired in the last century so that a catchy Christmas jingle finds it easy to poke its way into our heads?
Credit: Francesco Carta fotografo via Getty Images

The science behind your earworm

Earworm comes from the German word ‘ohrworm’ (for earwigs because apparently they crawl into your ear…) and most people have experienced one (the repetitive song, that is) at least once in their life.

While there’s an auditory prompt – you’re choosing between two toys on the shelf and ‘Last Christmas’ starts up on the department store loudspeakers – it’s actually the memory centre of the brain that is responsible for music like ‘All I Want for Christmas is You,’  ‘sticking’ in your mind.

The temporal lobe is part of the brain that’s closest to your ears (convenient, eh?) and processes sounds – birds chirping, car horns, people talking or weepy yuletide tunes – and is responsible for encoding it into memory.

This was tested in 2005 by a group from Dartmouth College in the US. They played two well-known tunes – ‘Satisfaction’ by the Rolling Stones and the ‘Pink Panther Theme’ – to participants undergoing a functional MRI. It showed the auditory cortex inside the temporal lobe ‘lit up’, but when the music stopped, it remained active, as if the brain was filling in the musical gaps. This, they suggested “offer a neural basis for the spontaneous and sometimes vexing experience of hearing a familiar melody in one’s head”.

Basically, if you’ve heard a song before, the parts of the brain that ‘hear’ the music can recall it, whether it’s playing or not.

And it’s those encoded memories that are essential to an earworm returning time and again: the more you hear a song, it seems the more likely it is to ‘stick’ and we can all attest to the Christmas classics getting a workout on high street speakers.

But there might be something else to earworms, beyond the brain, that makes them particularly memorable.

What makes music ‘sticky’?

Memory plays a role in being able to recall music, so it shouldn’t come as a surprise that familiarity is an essential ingredient for a song to lodge itself in our minds.

But are there characteristics that might make a song more likely to be recalled?

In 2016, Dr Kelly Jakubowski led a study into the features of a memorable melody. 3,000 UK participants were asked to name memorable songs, most of which were recently successful in the music charts. The tunes were analysed and it was found that earworms were more likely to be up-tempo; follow a typical melodic shape (they rise in pitch, they fall in pitch, and so on); but also use unique sounding intervals or repetitions to catch your attention.

It was also found that high-play radio songs were more likely to feature, though this might be a chicken and egg situation – do earworms naturally rate higher on the charts, or do they become earworms because they’re popular to begin with?

This year, the University of New South Wales found repetition that “catches the ear” of the listener is key.

“The implication [of the research] is that earworms might not have anything to do with the musical features at all,” said study lead Professor Emery Schubert, who researches music psychology at UNSW. “It largely doesn’t matter what the music is, as long as repetition is part of the music structure.”

How to shake it off…

So, you need to know how to get ‘All I want for Christmas is You’ out of your head? Are their science-certified ways to kill that earworm?

Researchers exploring the phenomenon have tried to answer this question over the years, with some solutions including:

Listening to the entirety of the tune, causing you to avoid looping the chorus, which tends to be the most repeated segment of music in an earworm.
Think about another song, which is the most common remedy people use, according to research from 2014.
Chew gum, which research from the University of Reading found disrupts motor processes used to ‘hear’ the music in your head.

The lists of earworms (don’t read past here if you don’t want one to crawl into your brain)

For what it’s worth, Lady Gaga’s ‘Bad Romance’ was the most reported earworm in the 2016 study, followed by Kylie Minogue’s “Can’t Get You Out Of My Head”.

Others included:

“Don’t Stop Believing” by Journey
“Somebody That I Used To Know” by Gotye
“Moves Like Jagger” by Maroon 5
“California Gurls” by Katy Perry
“Bohemian Rhapsody” by Queen
“Alejandro” by Lady Gaga
“Poker Face” by Lady Gaga

And for those gluttons for punishment, the most common Christmas earworm, at least according to BBC Science Focus, is Mariah Carey’s “All I Want For Christmas Is You”.