Can you tell us about your background and how you ended up doing musicality research?
I did my PhD at the Biological Psychology department at the Vrije Universiteit Amsterdam where I investigated genetic and environmental risk factors for childhood psychopathology. After I finished, I was asked to join Fredrik Ullén and Miriam Mosing for a year at the Karolinska Institute in Stockholm to do genetic research on music acquisition. I love music, so I took the job with enthusiasm. I ended up staying longer and over the years I became more interested in the connection between music and mental health. Continuing this line of research, I am currently employed at the Max Planck Institute in Frankfurt, which is in collaboration with the Amsterdam UMC location AMC, where I am mainly located. I also work one day a week at the Vrije Universiteit Amsterdam, where I do the genetic analyses for the department of Social Psychology.

What made you use genetic approaches to study musicality?

During my PhD, I became quite aware of the importance of genetics. However, most music research does not take into account that there could be individual differences due to genetic variation. This really biases the results. Take for example the common belief that you need to practice 10,000 hours to become proficient in anything. This would suggest that expertise is entirely environmental and that genetic influences are negligible, which we know is not true. In fact, studies have even found that the act of practice itself is highly heritable, even more so than musical skills. Moreover, practice effects differ among individuals; for instance, individuals with a stronger genetic predisposition for cognitive abilities experience amplified benefits from practice. Neglecting all these genetic influences can bias research findings, making them counterproductive or misleading. I think we should be very aware of the influence of genetics.

Your main focus is on the relationship between music and mental health, can you tell us about what you’ve learned thus far?

I am very intrigued by the relationship between music and mental health because the results have surprised me a lot. When I first started analyzing music and mental health in a dataset of 10,000 Swedish twins, I actually expected to find a positive relationship. People who play music do so because it makes them happy, right? However, I found that when you play a musical instrument you are more prone to mental health problems, especially burnout and depression. This relationship exists for both the amateurs and professionals, meaning that the enhanced risk of mental health problems is not just due to the stresses of being a professional musician. However, the relationship disappeared when I did a co-twin control analysis, which controls for genetics and family environment. So playing more music does not seem to cause mental health problems. I did a follow-up study where I found that polygenic scores for psychiatric disorders could predict musical engagement, even in mentally healthy individuals. So this confirmed that there are shared underlying genetic influences. On average, people with a predisposition for ‘music-related behavior’ also seem to have a predisposition for depression. But I am still convinced that music can be good for you, by allowing you to cope with mental health issues or just to relax and have fun.

Is there a critical period to learn music?

It is indeed often said that you should start before the age of seven to become very good at music, which is probably inspired by the fact that many famous artists and composers started practicing very early on. But these associations are biased by familial and genetic confounding. I did a twin study on this question of whether there is a critical period and we saw that an earlier starting age was associated with musical achievement later in life, which was still the case after correcting for years of extra practice. However, the whole association disappears when you control for genetic and shared environmental factors using twin analyses, which implies that starting at an earlier age does not causally increase the musical achievement, but that people with a genetic predisposition or a familial music-enriched environment just start at an earlier age. So there does not seem to be a critical time window.

Have there been large GWASs of musicality?

There are no large GWASs yet on musical talent or musical ability. But there has been a GWAS three years ago using 23andMe data, which is slightly music-related. The phenotype was “Can you clap to a beat – Yes or no?” Obviously, this phenotype definition is very limited, but it seems to tap into some general music behavior. I did a study in a Swedish twin cohort, which has rich information on music behavior, and I found that polygenic scores based on this GWAS can (weakly) predict music-related behavior and -skills.

If the ability to clap to a beat is not a good measure of musicality, what is?

I am part of the Musicality Genomics Consortium, which was recently founded to run a meta-GWAS on music training and talent. There is a group in our consortium that tries to answer this exact question of how to define musicality. I have listened to their discussions and got completely overwhelmed by how incredibly complicated it is. In our research we mostly look at two main components to musicality: lifetime musical achievement and music skills. Where the latter is composed of three basic elements, melody, pitch, and rhythm discrimination. They are all affected by innate abilities or talent, but also by practice and other things. Musical achievement, on the other hand, is about how good you become and whether or not you have a career in music. But you could also measure musicality in terms of how much people enjoy music. Related to all this is the question of whether musicality is uniquely human or not. We all know that songbirds produce music – but is it really music or is it communication? The same can be said about music in humans. As you see, I can’t give you a simple answer as to what musicality is. There are many ways to look at it and it is complex.

We heard that you are researching Beethoven’s DNA. How did you get his DNA and what are you investigating?

Beethoven died about 200 years ago after having been very sick his whole life. Before he died, he expressed the wish that he wanted someone to find out what had been wrong with him. Fortunately, his hair and parts of his skull were preserved. Recently they used this to sequence his DNA, which has been made public. He scored very high on polygenic scores for some diseases, but nobody checked his DNA for anything related to his musical achievements. So we are in the process of making polygenic scores for musicality, using the 23andMe beat clapping GWAS. The main aim of this project is actually to write about the practical and ethical implications of conducting such analyses on a historically significant individual, who lived in a very different society over 200 years ago.

If you weren’t a geneticist, what other field might you have pursued and why?
I would have become a primary school teacher (in classes of 6-12 year-olds), because I love to be around children, and I love to teach. I think it would be extremely rewarding as you can really make an impact and help to get the best out of children and see them grow and develop.