Dr. Bartels, could you tell us about you’re the years of your growing up, and when and how you decided to pursue your education in the areas of genetics and well-being and behavioral genetics?
When I was young, I was determined to become a medical doctor. So, my school career was focused on going to medical school. Medical school in the Netherlands, however, has a numerus fixus system ,and even after trying three times I was never the lucky one who got in.
To fill the time, I started to study Pharmacy, which I liked, especially the lab work. But I did not have a perspective as to my future. In my second year at university I became aware of the existence of the Netherlands Twin Register, which operates under the Department of Biological Psychology. So, I switched to Psychology and graduated in that department. I stayed there and completed my PhD with a focus on child psychopathology. At the end of my PhD studies I realized that the focus in the field of genetics is mainly on those who are ill, while the most people are not. So that is where I shifted my focus to happiness and well-being.
In lay person’s terms would you tell us about genetics and behavior in individuals?
We are all born with our genetic code in every cell of our bodies. Fifty percent is transmitted from the mother and the other 50% from the father. When genes are transmitted, they code for proteins that have all kinds of psychological functions. So a large part of the behavior of each individual is driven by genetic predisposition.
The title of your PhD thesis is extremely interesting. Could you please tell us about the associations that link behavior problems, cognitive abilities, and hormones?
Well, I studied these topics rather independently. So, I looked at the causes of individual differences in psychopathology throughout childhood and the causes of the differences in cognitive functioning in the early phase of life. I also investigated the daily pattern of cortisol secretion to find out if this was driven by genes or the environment.
Although it’s difficult to quantify, could you please tell us about how dependent our behavior is on the genes we inherit and the environment in which we grow up and, of course, the environment we live in during the years after we have grown up?
On average, about 50% of the differences in behavior between people are accounted for by genetic differences. There is variation in the heritability estimates. Differences in ADHD, for example, are about 70% accounted for by genetic differences, while differences in depressive symptoms are about 40% accounted for by genetic differences. The remaining variance is accounted for by environmental differences. There is, of course, also interplay between genes and environment. Genes can make you more or less sensitive to environmental influences or genes can influence your choice of environmental exposure.
According to other research, scientists have found that meditating just 20 minutes each day can change genetic responses and also the cognitive abilities of a person. Do you subscribe to this?
I don’t know, since I do not know which study you are referring to. You will not be able to change your DNA sequence, but you might be able to change your gene expression. These effects are person specific, so meditation might change gene expression in some but not in others. But once again, it’s hard to judge without the details of the paper.
Our readers would be interested in knowing about your journey to the illustrious position you have reached.
What do you mean by my journey? Like any scientist, I am driven by curiosity and I am fascinated by the differences between people when it comes to well-being and happiness. So every project contributes a small piece to a big, complex, and extremely fascinating puzzle, while each project also brings about new research questions.
Before we conclude, Dr. Bartels, our readership consists mainly of young people in different parts of the world who look up to the educated elite. What would your advice to them be?
Do what you like! Pursue what fascinates you! Life treats you better when you invest your energies into being who you are.