Nature versus nurture. These words have been drilled into us ever since we attended our first biology lecture. Not everything can be predicted by our genetic makeup nor is everything an outcome of our environmental exposure. Some things are a result of the environment while other traits are embedded in our genes. And then there’s epigenetics. An entire field of science dedicated to studying the interplay of genes and environment. We now know that genes and environment cannot be studied in silos, rather, the environment itself affects how genes are expressed and it is the interplay of these two characteristics that make up our very being. Yet despite our understanding of epigenetics, scientists are still trying to determine just how much of our development can be explained by nurture and how much has been left to nature.

In the latest mega-study, researchers at King’s College London, followed over 13,000 pairs of twins over a period of 12 years and came up with a genetic and environmental hotspot map showing that the weighting given to genetics versus environment in one’s development is strongly influenced by one’s geographic location. At first blush, these findings sound fairly obvious. After all, isn’t the whole point of nature versus nurture to show that environment plays as much of an important role in development as does genetics? Not so, explain the researchers. Popular theory contends that all facets of development are influenced by both genetics and environment. However, according to the KCL team, exactly how much of your development is determined by genetics and how much is determined by environment may be largely attributed to where you live.

Confused? Let me try to explain.

Take, for example, hay fever allergy. If a set of genetically identical twins were to have the hay fever gene, then their susceptibility to developing hay fever should be genetically equal. Place one set of twins in a region with lots of pollen and the other set in a pollen-free region and you will find that only the set of twins in the pollinated region will develop hay fever. Therein lies the concept of the genetic hot spot. A region with a lot of pollen is a genetic hot spot for hay fever since people hat are genetically susceptible to hay fever will only get it in the pollinated region.

Still confused? So am I! All this study says to me is that if you are genetically susceptible to reacting to an environmental condition, the reaction will only appear if and when the environmental condition are present. Isn’t that obvious?

Have a look at the article on the Wellcome Trust page and let me know if I am missing something.