During my studies in clinical psychology I often run across a theory called the biopsychosocial model of mental health. In a nutshell, this theory says that mental well-being (and mental illness) is affected by a combination of biological (genetic), psychological, and social factors.
What this means is that just because you have a genetic predisposition to a particular mental illness, such as schizophrenia or depression, does not mean you will necessarily develop the illness. Whether or not you actually develop schizophrenia depends not only on your genetic makeup, but also on other factors in your environment.
This theory is widely accepted by psychologists and psychiatrists alike, and is supported by a variety of research, including studies of twins separated at birth. As you may or may not know, twins have identical DNA. Yet, twins that are separated at birth and live in distinctly different situations often bear little resemblance to each other. The obvious explanation is that genes are not the end all be all of behavioral development, and something else is at play. That something else is the environment.
Which leads us to epigenetics…
What I have described above is an example of epigenetics at work. In a nutshell, epigenetics is the study of what happens to our genome’s (DNA sequences) over our lifespan. Not so long ago – like before the 1970’s and even into the 80’s and 90’s – scientists were reasonably convinced that the human genome had the final say in who we become in life. Genes governed everything from mental well-being, to personality, to physical appearance, to what we liked to eat for dinner. You could not escape your genes.
Fast forward to today, and what scientists are finding is that the genome – while important – is not the end all be all of human development. We now know that there is another player – the epigenome. The easiest way to think about how the genome and the epigenome work together is to think of the genome as the hardware, and the epigenome as the software that tells the hardware what to do.
So while you may share a lot of the same genes with your parents, you are not necessarily going to develop the same traits, because you may have different epigenetic tags (software) telling your genes whether or not to activate, and to what degree.
Here is how epigenetics works
As I mentioned above, the epigenome is like software that controls the hardware of a computer; i.e. the genome. But who or what is programming the software? That is where the environment comes in. Your environment – the people you hang around, the situations you find yourself in, the food you eat, etc. – is the programmer of the epigenome.
And this is awesome news. Because even though scientists now believe that many of the epigenetic markers are in fact passed from one generation to another, you can control and change those markers by making healthy choices about your environment and lifestyle.
In other words – your past is not necessarily your future. Even if you are in your 50’s or older, you can still influence your epigenetic markers by making changes in your environment and lifestyle, and reduce the risks of developing certain diseases, or even extend your life by years.