Moderating influence
“People may turn probability into prophecy.”
Approach with caution” has been a common – and expected – response to Robert Plomin’s Blueprint thesis. But local scientists say it has its uses. Tony Merriman, a professor of biochemistry and genetics at the University of Otago, respects Plomin’s approach and points out that he is careful to talk about genes influencing, rather than determining traits.
Merriman says genetic comparisons of human populations are a “no-go area” when it comes to intelligence but “very useful for a researcher like me studying diseases such as diabetes, gout and malaria, which some populations are more vulnerable to.”
Hamish Spencer, a professor of zoology at Otago and a eugenics historian, says we mustn’t lose sight of the importance of environments to how people turn out.
“Knowing your genetic make-up can be useful to warn you about your susceptibilities to, for example, breast cancer, but it could just blight your life with worry about things that may never happen and that you can’t do anything about,” Spencer says. “People may turn probability into prophecy.
“We must concentrate on what we can do to create environments and lifestyles that enhance our genetic advantages and minimise any disadvantages.
“We’re not going to be able to edit out the hundreds, if not thousands, of genes that contribute to autism, for example, but we can prevent known triggers for depression or schizophrenia. For example, some people have a predisposition to develop schizophrenia if they smoke cannabis at a young age.
“And a mother-to-be’s poor nutrition can precondition a fetus to develop diabetes and cardiovascular diseases later in life by moderating the function of genes. The fetus is trying to anticipate its ex-utero environment by adapting its physiology and getting it wrong. It seems that even obese fathers can have an influence on their offspring.”
We mustn’t lose sight of the importance of environments to how people turn out.