What do genes really mean? / by Gia & Danielle

By Dr. Danielle Keenan-Miller

It seems like everything is “genetic” these days—from having a sense of purpose in life[1] to political affiliation[2], and it’s a term that often gets mentioned when describing the causes of psychological disorders. But what does it really mean to say that a psychological problem is genetic? Does that mean that it’s our fate, passed down in our DNA from our ancestors, some kind of self-fulfilling prophecy? Should we give up on trying to prevent or treat these problems and instead view them as an unfortunate part of our biological programming?

Luckily, no. The picture is much more hopeful than that, particularly when you understand what scientists mean when they say something is “genetic.”

When the human genome project started in the 1990s, scientists and public officials believed that we would find the “codes” that created all sorts of human traits, good and bad. It was assumed that the risk for all sorts of diseases would be found like typos in our genetic code. And that was true for some diseases-- like Cystic Fibrosis (CF). A certain kind of mutation on the CFTR causes Cystic Fibrosis[3]. If you have that kind of mutation, you have CF. If you don’t have that type of mutation, you don’t have CF. Simple, right?

But nothing similar has ever been found like that for a psychological problem. It’s widely believed that lots of genetic mutations may cumulatively have small effects on various aspects of our mental health, but no one gene or even series of genetic changes are enough to cause mental health problems. For example, schizophrenia is the psychological disorder most strongly tied to our genes. However, if one twin has schizophrenia, the chance that his identical twin—with 100% of the same genes—has schizophrenia is only 50%. [4] And that’s for the most “genetic” of all mental health concerns! That means that our environments, the experiences we have in our everyday life, and the choices we make have a BIG impact on our mental health outcomes.

So what do genes do? Your genetic code might mean that you’re more likely to have the same kinds of problems that others in your family have. Genes might make us more susceptible to certain kinds of stressors[5] or predispose us to traits like impulsivity[6]. But they aren’t genetic fate. They’re more like a nudge, but one that doesn’t have to set you off course as long as you’re mindful of it and take active steps to promote your own health. Just because binge eating has a genetic component[7] doesn’t mean that you’re stuck with a lifetime of compulsive overeating. One of the goals of this website is to help you understand how to use the newest discoveries in psychological science so to take charge of your own mental health and happiness. Read on for our tips on how to build the best life you can, regardless of your DNA.  

[1]  (http://onlinelibrary.wiley.com/doi/10.1111/j.1467-6494.2012.00787.x/abstract)
[2] http://www.sciencedirect.com/science/article/pii/S0191886913001384
[3] https://ghr.nlm.nih.gov/gene/CFTR
[4] http://www.sciencedirect.com/science/article/pii/S0006322399002899
[5] http://www.annualreviews.org/doi/abs/10.1146/annurev.clinpsy.1.102803.143938
[6] http://rstb.royalsocietypublishing.org/content/368/1615/20120380
[7] http://www.ncbi.nlm.nih.gov/pubmed/18095307