For many centuries, long before
the discovery of DNA, psychologists and biologists alike have debated over how
much of who we are is controlled by the environment. This “nature versus
nurture” debate has now gotten much more intricate as it has expanded to include
the influence of external and internal environments on how our DNA is read and
interpreted by our bodies. With all the new information available to us today,
it is easy to focus on the genetic basis of life. However, studies looking at
the links between our DNA and specific conditions make it clear that the role
of our environment cannot be overlooked. For example, recent research shows
that about 50% of the factors that influence intelligence are inherited.
This means that half of the factors controlling intelligence are NOT inherited.
In fact, it has also been shown that especially for children, education,
nutrition, and even a peaceful, nurturing home environment all contribute to intelligence. Similarly, the heritability of depression is at about 38%,
meaning that 62% of factors leading to depression are under the control of our
environment.
Several studies conducted on the
heritability of diabetes put this number between 25-80%. These same studies are
quick to point out, however, that the effects of genetics versus those of living
in the same environment are not completely separable.
Researchers agree, though, that the
interplay between the environment and genetics is crucial to the development of
this condition. Similarly, interactions between genetics
and the environment are responsible for heart disease and asthma.
Obviously, there are some illnesses that are purely inherited, and knowing your
family history is important as it tells you what conditions you may be at an
increased risk for. Still, it is nice to know that by trying to live a
healthier life physically, mentally and emotionally, I can influence whether or
not I develop certain conditions and to what extent.
What, then, is my most important contribution
to my children’s lives? Probably not their DNA. Creating a healthy environment
for them to grow and thrive, helping them develop good eating habits, teaching
them to value themselves and others, and to be kind, and showing them that they
can make a difference in the world are all just as important, if not more important
than genetics. Our
DNA is an inheritance given to us without our consent, one which we pass on to
our children without asking for permission. Luckily, we have a significant
amount of control over the external factors that influence our make-up, and we can
help build the best versions of ourselves, and of our families, upon the
foundations laid by our DNA.
