About a year ago I absent-mindedly searched for ‘Mozart for babies’ on YouTube. I can’t actually remember why I did it — it was probably something to do with my nephew having just been born — but I immediately regretted it. I was presented with tens of videos with some of the most annoyingly search-optimised titles I’ve ever read. Things like Mozart for Babies brain development -Classical Music for Babies-Lullabies for Babies (that’s just one title) and Baby Sleep Music, Lullaby for Babies To Go To Sleep #020 Mozart for Babies Intelligence Stimulation (that’s another). But maybe more annoying than the titles themselves were the view counts. That first one — I won’t repeat the name — had nineteen million views when I last checked. Mozart has become a sort of God in the child development world, a go-to genius to give your baby the leading edge in the race to become the most intelligent toddler. But what fascinates me more than these view counts is how we got to this point. Can playing Mozart to your unborn child actually make them smarter? Well, to work this out, we need to go back nearly thirty years, to the study that initiated this decades-long craze.
In 1993, a group from the University of California decided to investigate the relationship between cognition and music, looking, in particular, at the effect of Mozart’s music on the performance of some students in a handful of spatial reasoning tests. They took thirty-six undergraduates and asked them to complete three tests after experiencing three listening conditions — ten minutes of silence, ten minutes of a spoken relaxation tape, or ten minutes of the Sonata for Two Pianos in D major by Wolfgang Amadeus Mozart. And what they found seems unbelievable. After listening to the relaxation tape, students gained, on average, one spatial IQ point as compared to taking the test after ten minutes of silence. But after listening to Mozart’s sonata, the students performed considerably better, scoring eight to nine IQ points higher than the silence benchmark. The music seemed to have unlocked a ‘hidden’ intelligence. So, maybe this was the secret to being smart all along? All we needed to do was find a way of listening to Mozart’s Sonata for Two Pianos in D major all day long! Obviously, I’m being flippant here — although I wouldn’t mind listening to the piece for a whole day — but considering what happened in the years after this study, my suggestion might not seem that extreme.
In August 1994, music critic Alex Ross wrote a very tongue-in-cheek article for the New York Times about the so-called Mozart effect, which opens with the following inimitable line:
‘Beethoven is no longer the world’s greatest composer…His place has been taken by the one beloved by God, the supreme artifice of music, the sublime Mozart, who was also a more reliable worker and a nicer guy.’
I have no idea how you would not take the article with a pinch of salt, but people can be pretty tunnel-visioned when it comes to drawing the conclusions they want.
Later in the piece, whilst talking about the 1993 study, he says that ‘researchers have determined that listening to Mozart actually makes you smarter’ and, of course, this is what people latched on to. Major news outlets published articles suggesting that listening to Mozart could improve your IQ — even though the original study focused specifically on spatial reasoning — and soon everyone started to believe the myth. Studies were commissioned to validate the original findings, tapes and CDs featuring Mozart’s music became bestsellers, Don Campbell published two books all about how Mozart can make you and your children more intelligent — each with their own accompanying CDs and merchandise, of course — and at the peak of Mozart-madness in 1998, Georgia Governor Zell Miller proposed a $105,000 annual plan to provide every child in the state with a CD of classical music. ‘Now, don’t you feel smarter already?’ he said to some legislators whilst playing them the Ode to Joy from Beethoven’s Ninth Symphony. Somehow, despite the original study focusing on college-aged students, the Mozart effect had become all about children, and even children who hadn’t been born yet. Possibly one of the worst things to appear out of all of this was the so-called baby belts — loudspeakers that wrapped around a mother’s belly, allowing them to pipe Mozart directly into their uterus.
But in the 2000s, the Mozart effect began to lose its potency. Few studies were able to reproduce the huge spatial IQ boost seen in 1993, and, maybe a little suspiciously, the teams that got closest to the original results were ones affiliated with the researchers who led the original study. It’s now generally agreed that the effect was caused by increased arousal. Mozart’s Sonata for Two Pianos in D major is a crystalline and blazing work — it’s athletic, agitated, and alive, and it’s no wonder the students performed better after listening to it for ten minutes. They were high off Mozart’s music. And this effect can be recreated using any type of music that causes increased arousal levels and can even be achieved with other forms of media. One study found that listening to a Stephen King audiobook can lead to the same boost in performance, as long as you like Stephen King, of course. And as for those baby music belts, well a study in 2015 showed that, at best, these are ineffectual — most frequencies emitted from the small speakers don’t even get to the foetus — and, at worst, playing music directly into the womb could cause potentially long-term damage to your baby’s ears.
So, where does that leave parents-to-be? What part can, and should, music play in the development of their unborn son or daughter? Well, for this, we need to look at a slightly more credible study that used slightly less credible music. Music is often used to study foetal development and learning because sound is one of the only ways we can interact with a developing child. The thick layer of skin, fat and muscle tissue between the outside world and the womb does a very good job at filtering out most high frequencies of sound — acting like a natural low-pass filter — but a lot of the subtleties of music and speech are preserved, and so heard by the growing foetus. Studies have shown that in the last trimester of pregnancy, a child’s movement and heart rate will change when they hear their mother’s voice, and their mother’s voice only. A lot of the substance of that voice — the hard, high frequency consonants, clicks, and noise — is lost, but the melody, the rhythm, and tone colour of the voice can all be heard, and learnt by the child. Newborn children will respond to their native language, but interestingly, they struggle to distinguish similar-sounding languages. In 1998, Thierry Nazzi and his colleagues found that French infants can easily discriminate English from Japanese, but not English from the phonetically similar German. A child learns what’s called the ‘prosody’ of the voice — the rhythm, the tone, and the stress. And the same works for music.
In 1991, a group led by Peter Hepper from the University of Belfast investigated foetal learning by seeing how both unborn children and newborns responded to a specific piece of music. Hepper wanted to assess ‘natural’ learning of the music, and so chose a tune which he assumed the vast majority of pregnant British mothers would have been exposed to in the early 90s — the theme tune from the classic Australian soap opera, Neighbours. It really is quite difficult to overestimate just how popular Neighbours was in the UK at the time, but to make this a fair experiment, Hepper did also need to find mothers who, somehow, hadn’t watched the soap at all. Of those mothers that did regularly tune into the show, Hepper estimated that during pregnancy, their unborn child would have heard the theme at least 360 times — more than enough for the baby to, in theory, ‘learn’ the music.
And so, once the child was born, it was then time to test whether they had learnt the theme tune whilst in the womb. Two to four days after birth, the newborn infants in both the learning and control groups — the mothers who had and hadn’t watched Neighbours respectively — had their first opportunity to hear the music outside of the womb, and whilst they were listening, Hepper observed and recorded the child’s response. He noted down their movement — looking at the legs, arms, and head — their behaviour — from sleepy, to alert, to crying — and he measured their heart rate. And he found remarkable differences between the two groups of children. Infants in the learning group had a reduced heart rate, they moved less and tended to be more alert, a state associated with deep learning and focus. And this learning was highly specific. When two-day-old infants from a new set of mothers were played either the Coronation Street theme tune or the Neighbours theme tune backwards instead of forwards, none of the changes in movement, behaviour, or heart rate from the first experiment were observed, even if the mother had regularly watched Neighbours during their pregnancy. Despite the significant filtering of frequencies and information between the external world and the womb, the babies had heard, internalised, and learnt the melody, rhythm and contours of this upbeat theme tune from the 1980s.
But there’s still one question which hasn’t been answered here. How long does this learning effect last? In one experiment as part of the same study, Hepper recorded that after twenty-one days, the infants in the learning group responded as if they had never heard the theme tune before. So, maybe the learning was only temporary? Maybe any music or sounds learnt in the womb needed to be reinforced through further exposure once the child was born? Well, this conclusion has been challenged by a 2013 study conducted by Finnish researchers. Similar to Hepper’s study, Eino Partanen and his team tested newborn’s response to a piece of music after their mothers had listened to that music multiple times during their pregnancy — in this case Twinkle, Twinkle, Little Star. But in Partanen’s study, the mothers were asked to actively listen to the music, instead of passively as with the Neighbours theme, and instead of analysing the child’s response using heart rate and observed behaviour, they used an EEG, measuring the brain’s response to the music. Similar to the Neighbours theme tune, the children who were exposed to Twinkle, Twinkle, Little Star during pregnancy exhibited a significantly stronger response to the music than those that hadn’t, but unlike the prior experiment, this response was still present and significant when they were tested an astonishing four months later.
Melodies heard in the womb and music played in a child’s environment during pregnancy have the potential to form long-lasting neural maps in the brain — a set of powerful, interconnected pathways formed at a time when the organ is undergoing seismic changes. Mozart might not make an unborn child smarter, but music, even Mozart’s music, has the power to change the wiring in a foetus’ brain — they can learn music and sounds long before they’ve seen, smelt, tasted, or touched anything in the outside world.
So, what should parents play to their unborn child and how? Well, I don’t recommend you buy a baby belt and blast Mozart at them, but you could play Twinkle, Twinkle, Little Star through a set of speakers, or you could even just turn on their favourite soap opera or sitcom. But the most powerful tool at a parents’ disposal is something that’s been around for a lot longer than all of these things — the human voice. If I were to give new parents one piece of advice, it would be this. Don’t go onto YouTube and play Mozart for Babies brain development -Classical Music for Babies-Lullabies for Babies. Sing to them. As to what you sing, well that’s up to you.