At the end of the 20th century, there was a lot of
excitement around the unveiling of the secrets of the human genome. But
one of the results of all the excitement was a rather grim view of
human beings as victims of our genes. People became frightened at the
prospect of discovering they might have the dreaded gene for cancer,
dementia, or some other horrible disease for which there was no cure.
Also according to this view, if you were unusually gifted at something – like music, sports, or academics – you deserved little if any credit for it. You just happened to be born with good genes.
And if you were lazy, overweight, anxious, or depressed – well, that had very little to do with you as well. It was just your unfortunate genes.
But it turns out that was a mistaken view.
We are not the helpless victims of our genes. In fact,
there’s a whole new area of genetics, called “epigenetics,” that tells a
far more hopeful story.
You may be born with a scary-sounding gene, but whether or not that gene becomes activated depends a lot on you.
Our genes are located along strands of DNA. If you think
of the DNA strand as a piano, then the genes are like individual piano
keys or notes you can play. On a piano, it’s only the keys that are
actually being played that make the music we hear. In the same way,
it’s only the genes that are “played,” or activated, which affect our
physical and mental makeup – including everything from eye color to
height, intelligence to physical health, and various aspects of our
What determines whether or not a gene is active?
There are chemical reactions within our cells that act like switches, turning a gene on or off at specific times for specific reasons.
So for example, we have genes that cause cancer, and genes that prevent it. Whether or not we actually get cancer depends on which of those genes is switched on and which is switched off. Epigenetics is the science that studies the factors that influence when and how particular switches are turned on and off.
There are some factors that affect our gene switches that we have no control over - things like the degree of nurturing we received as kids, or the level of toxins in the air we breathe and food we eat.
However, there are many factors over which we potentially have a great deal of control – meaning there’s a lot we can do to affect which of our genes get activated. For example, how much exercise we do, or what kind of food we eat can affect whether certain genes are turned on or turned off. What’s perhaps more surprising is that even our thoughts, our moods, and our ability to focus our attention can influence whether or not the genes for diseases like autism, diabetes, asthma, schizophrenia, and heart disease get activated.
To give a specific example, say you have a gene, which when active, would cause you to have ADHD (attention-deficit/hyperactivity disorder). By learning to focus your attention through breathing and related techniques, the activity of the “ADHD” genes can be reduced or turned off altogether.
But epigenetic factors not only have the power to make us healthier, they can also make us sick.
Stressful situations – like losing a job or being in a war
– often cause the release of stress hormones. If the stress is
long-lasting, these hormones can negatively affect both our physical and
mental health. The hormones also act as epigenetic factors that
influence our gene expression. Even after a stressful event is over,
its effect on our genes can continue for months or even years.
So does that mean the effect of stress on our genes dooms us to long-term physical and mental suffering?
Some people who have genes for dementia actually develop
the disease, whereas others with the same genes do not. Why the
difference? Research hasn’t yet come up with a definitive answer, but
early results clearly point to the likelihood that epigenetic factors
like smoking, psychological trauma, diet, exercise, and the way we
manage stress all play a role.
So if you want to greatly increase your odds against getting dementia as you get older, it’s a pretty safe bet you can do so by increasing your stress tolerance, eating well, exercising moderately – and perhaps most important, developing your MPFC. And that’s true even if you have genes that predispose you to developing it.
Science writer, Sharon Begley, sums up the field of
epigenetics this way: “The genes in our cells don’t matter one iota if
they’re not turned on, and there are many things in life that can turn
off bad genes (such as those that raise the risk of breast cancer) . . .
It really is time to stop thinking of our DNA as immutable. Even
thinking can change it.”
Most people accept the idea that childhood experiences can
influence how we turn out as adults. And you probably don’t need
scientific research to tell you whether the outcome will be better or
worse when kids are treated with love and care. But scientists are now
discovering some of the specific biological mechanisms by which loving
care can change the way our genes are expressed.
Dr. Michael Meaney, a neurologist at McGill University, observed that rats who received extra licking and grooming as babies grew up to be more intelligent and less susceptible to stress than baby rats who received less attention. He then discovered that the well-nurtured rats produced less of a stress hormone called cortisol, and that their hippocampus – a part of the brain involved in mood stress regulation – was more developed.
It’s helpful that scientific research has now confirmed what we already knew – that it’s good to love and care for your children. It may also be helpful to know that a number of scientific disciplines have now identified specific qualities which you can develop by training your brain that promote optimal gene expression – qualities like self-awareness, self-regulation, persistence in the face of failure, compassion, and optimism, among others.
If you’ve gotten this far reading through the brain pages on this site, you’ll have no trouble recognizing these as qualities of a balanced, integrated brain!
And now there’s overwhelming evidence that these qualities are also better predictors of future academic and occupational success than a person’s IQ score!