Nano Girl Michelle Dickinson: There's no one gene to outsmart them all

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Over the last week downtown Auckland was filled with long black gowns and stiff mortarboards as another university graduation ceremony took place, the students - along with their families and friends - rightly proud of what they have accomplished and excited to see what the future holds.

As a university lecturer, celebrating the successes of students is a genuinely joyous occasion. During the ceremony this week, I started wondering what sets graduates apart.

What has seen them successfully pursue higher education, where others have not? Is it nature - some sort of innate ability - or a nurtured skill more related to our environment and upbringing? This week one of the largest studies of the human genome was published in Nature, and it offers some interesting insights.

Previously, research into twins and other siblings estimated that around 20 per cent of the differences in educational achievement between individuals could be accounted for by genetics. Building on that estimate, numerous studies have attempted to identify the specific genes responsible for traits like intelligence, raising questions around whether you would make different life choices knowing you were genetically "pre-programmed" to be academic.

The idea of a single "intelligence gene" brings up future ethically-challenging considerations around designer babies; Would you, for example, be willing to increase the academic potential of your future child by carrying out an artificial gene tweak on conception?

Thankfully the idea of a single intelligent gene was quashed by this week's new study which found that the largest effect of any one genetic variant was a tiny 0.035 per cent. This means there is no one gene that outsmarts them all, instead several thousand different genes work together with combined responsibility for academic success.

Analysing results from nearly 300,000 European adults, the study identified 74 genetic variants that were associated with the number of years spent in formal education. Although the effect of these variants was too small to predict the educational abilities of an individual, the data was useful for looking at big picture population correlations of the relationship between personality traits such as grit and contentiousness with education attainment.

The scientists went on to analyse 9 million sections of DNA to create a polygenic score - which reflects how many genetic variants an individual carries and how they relate to health, development and personality traits.

One of the most important polygenic studies is the Dunedin Multidisciplinary Health and Development Study, internationally renowned as one of the most significant long-term health projects ever conducted. Tracking the lives of 1037 New Zealand babies born in the 1970s, the study has helped identify genetic variants involved in prenatal brain development as it follows how its volunteers learn, helping us to understand the biology behind neural development and academic intelligence.

Although this study was looking for genes associated with educational attainment, the research also uncovered a new perspective on previous research which found that having more education reduces the risk of Alzheimer's. The new hypothesis is that these variant genes associated with education success might also be the same genes connected to certain brain diseases.

So as a new set of students go out into the world, it's nice to know genetics played only a very small part in how studious they were. Their hard work, supportive social network and determination played the biggest role in their educational success.