Icelandics are descendants of Norwegians. For a thousand years they lived in relatively harsh environment. In the end only those with strong genes survived.
“Without an environment that we call tobacco smoke, you’re not going to develop lung cancer in Iceland,” he said. “But you inherit compulsion to seek the environment.
“Your brain is hard-wired by genetics. And it decides in many ways what you do and how you do it. So there’s very little free will,” Stefansson said.
“There is no God, there is only DNA,” he added with a laugh. “There is a lot you can do, but you have to realize you are always battling yourself in everything you do to try to prevent your genetic destiny from becoming a reality.”
The harsh conditions of life in Iceland in past centuries — unheated homes, agricultural hardship, widespread poverty — may have mean those with tough genes were more likely to survive, reproduce and pass that hardy DNA down the line, Stefansson said.