Thursday 9 February 2012

Music Training and IQ

No one doubts it: Parents have a hard job.  In addition to all the day-to-day cooking, cleaning, cajoling, and ferrying kids about, parents have to make big decisions about what’s best for their child.  We all want our kids to be well-adjusted, happy, and living up to their potential.  And one of the trickier minefields to maneuver through is the choice of extra-curricular activities.  Dance, swimming, drama, a multitude of team sports, martial arts, chess club, scouts, Mandarin class, gymnastics, the list goes on.  Oh, and did I mention music?  The parent has to weigh out the time involved, the child’s eagerness to participate, and the potential benefits to the child.

Does music training make you smarter?
Which is, of course, where I’m going with this.  It’s hard to nail down all the benefits of musical training, but one that keeps coming up again and again is the idea that musical study makes people smarter.  But does it?  A few weeks back I advised you to take research about music and IQ with a grain of salt.  Ask around, and you’ll hear that people who study music are smarter overall than people who don’t, and the common assumption is that the musical training itself contributes to the increase in IQ.  But the causation could run the other way too:  people who are smarter are more likely to take and stick with music lessons.  The basic question is this:  Does studying music make people smarter OR do people study music because they are smarter already?

The only way to really test this question is by a longitudinal study, where people are randomly assigned to either receive music lessons or not, and the effects on IQ are studied.  In the last decade, there have been a couple of good studies that have investigated this question.

Figure from Schellenberg (2004).

Music training leads to a greater increase in IQ
The first, a study by Glenn Schellenberg at the University of Toronto was published in 2004.  In this study, 6-year-old children were placed into four different groups:  piano classes, voice classes, drama classes, or no classes.  The children were given IQ tests at the beginning of the study, and at the end, after 36 weeks of classes.  All groups showed an increase in IQ, which is expected, because they were 9-10 months older, and had been attending school during that time.  But here’s the key result:  children taking music (piano or voice) classes had a slightly larger increase in overall IQ compared to control or drama students.  The researchers made sure there were no overall differences in the parent’s socio-economic status between the four groups, and included the drama class control group to prove that it was specifically music and not extracurricular activities in general that improved IQ.

Music training causes structural brain changes
In 2009, a similar study was published by a group of scientists in Boston. In this study, there were only two groups:  one group received 15 months of keyboard lessons, and the second group received no lessons.  The children were given a set of behavioural and IQ tests before and after the 15 months and it was found that keyboard training increases performance on finger fine-motor tasks and melodic and rhythm discrimination tasks.  However, this study found that there were no significant differences in IQ between the two groups of children.  This result may be due to the small number of children in this study.  Only 31 children were studied, compared to 144 in the Schellenberg study.  When the differences to be observed are small, a large number of test subjects is required.

The Boston researchers went one step further and performed MRI brain scans of the children before and after the 15 months of training.  Amazingly, they were able to show that musical training causes structural changes in children’s brains.  Children who had 15 months of keyboard lessons had more growth in the following areas (compared to children with no music training):
  • The corpus callosum, which connects the two sides of the brain
  • The right primary auditory cortex, which processes sound information
  • The right motor cortex, especially the hand area, which controls the left hand
  • The left and right frontal cortex, involved in working memory and the processing of harmony and tonality
So musical training causes changes in the brain, but for the most part, these changes occur in the places that one would expect, the parts of the brain that are involved in music processing and production.  Does growth in these parts of the brain lead to improvements in overall intelligence?  I would argue that it could, especially growth in the frontal cortex.  As I reported back in November, the frontal cortex is involved in a variety of general-intelligence skills known as “executive functions”, and these have been shown to improve in preschoolers taking music classes.  Increased connectivity between the two sides of the brain through an enlarged corpus callosum could also contribute to improved mental processing.  And a more finely-tuned auditory cortex could allow for improved verbal skills.  In sum, structural changes in the brain caused by musical training could certainly underlie a small increase in general intelligence.

But is this really the main benefit of musical training?
I should reemphasize that this 2009 study did not find any overall increases in IQ.  I think most researchers believe that the enhanced brain growth and rewiring caused by musical training results in an increase in overall intelligence, but the effect is small.  If we only focus on the benefits of musical training on intelligence, I think we are missing the boat.  Music offers so much more than this:  a vehicle for self-expression, training in self-discipline, solace, an opportunity to stand up in front of people and perform, a chance to be really good at something.

Personally, I want my children to study music simply for the joy of making music.  There’s nothing like it.

  • Schellenberg EG.  (2004) Music lessons enhance IQ.  Psychological Science 15(8):511-514.
  • Hyde KL, Lerch J, Norton A, Forgeard M, Winner E, Evans AC, Schlaug G. (2009) Musical training shapes structural brain development.  Journal of Neuroscience 29(10):3019-3025.

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