What makes children smart: genes or environment?

A UCD professor sparked controversy when he claimed top students from affluent backgrounds do better due to genetics. We asked experts for their views

Do children from more affluent backgrounds do better in school because they have more resources, or because they’re genetically superior?

In a recent letter to this newspaper Dr Michael O'Connell, associate professor of psychology at University College Dublin, sparked debate and controversy when he claimed that high-performing students do better not predominantly because of wealth, but because they "inherit higher cognitive ability" from their parents.

His letter followed a new study from the Higher Education Authority which showed that students from wealthier backgrounds are more likely to study high-points university courses and earn more within months of graduation.

The findings, which back up nearly 20 years of data from The Irish Times feeder school lists – which measure the proportion of students who progress to third-level by individual school – are not surprising. But why do children from wealthier backgrounds do better?


“Once parental ability is accounted for, social background of their children plays only a very modest role – so long as the threshold into extreme poverty is not crossed – despite the widespread assumption that social background must be decisive in such matters,” O’Connell wrote.

Speaking to The Irish Times, O’Connell says that he is not trying to write off chunks of the population.

"There is greater variability within schools than between schools. The evidence I have seen from geneticists such as Prof Robert Plomin and Dr Emily Smith-Woolley of King's College London suggests that "public schools" in the UK [the equivalent of fee-paying schools in Ireland] perform well in league tables because schools' reputations are used to attract higher-ability cohorts the schools themselves aren't doing anything that special."

O’Connell is among a group of geneticists and psychologists who believe that 50 per cent or more of intelligence is determined by genetics.

“Genes do depend on a person’s environment: you may have the gene for height but, if born in a famine, that won’t express itself,” he says.

“We know from adoption studies that children have similar traits to their birth mother, more so than traits they pick up from their environment.”

Others are skeptical of these assertions and say a focus on whether intelligence is more influenced by genetics or by environment might be largely pointless.

At Maynooth University, Dr Bryan Roche has been leading a team on the development and testing of Smart (Strengthening Mental Abilities with Relational Training), a computer programme which, they say, can dramatically boost IQ.

“The stability of IQ is a statistical illusion,” he says. “It is the default position of unambitious science. The better the education system, the less genetics matters.

“We know that IQ can rise or fall due to sleep and diet, by about five points. But our team is now on the seventh replication of our study which shows that, with intensive and focused educational intervention, you can improve IQ by up to 15 points – though still we have found it difficult to cut through the noise that IQ is fixed for life.”

Like a marathon runner at their peak, a child with an IQ of 120 may have already maxed out – there are no more variants left in the system.

"When we intensify education and deliver programmes to enhance a child's cognitive ability, we see the scores of the lower-performing group rise more than those with higher scores. Ireland, however, has a one-size-fits-all education system and we are not investing enough."

Educational interventions can change educational outcomes – reducing the proportionate effect of genetics, Roche claims.

“Science is only now learning the significance of relational reasoning: that how we understand the relationships between things is central to how humans understand the universe. Intelligence is a form of relational reasoning, which is easily taught, and so IQ can be raised.”

Dr Kevin Mitchell, associate professor in developmental neurobiology and genetics at Trinity College, is the author of Innate, which looks at how genetic differences play out in our personalities, intelligence and psychiatric conditions.

“We do not start as blank slates,” he says. “We are born different from one another. There is a correlation between intelligence and socioeconomic success, but to claim that this explains unequal third-level progression rates ignores the other factors that we know are at play: some schools have more resources, and some parents have more resources to invest in their child’s education.”

Genetics accounts for more differences in wealthier schools, but where people have lower socioeconomic status, the variations are more influenced by environmental differences because not everyone has been given the same potential to flourish, says Mitchell.

"I am currently the dean of undergraduate studies. College admissions is one of my briefs. Our Trinity Access Programme brings in students from disadvantaged schools which don't have the same resources.

“It takes work to get them into college but, once they are here, they do just as well as other students. It is clear that there is an unequal distribution of resources and that this is reflected in Leaving Cert results.”

“Psychology is a caring profession and we should be helping people,” says Roche.

“But if attainment is limited by genes, why bother? There’s a real ethical danger in this viewpoint; in the past, the idea of ‘genetic superiority’ has been abused by eugenicists and white supremacists.”

O’Connell, for his part, points out that he was once involved in organising a public discussion opposing The Bell Curve (1994), a hugely controversial book that claimed there were racial differences in intelligence and which has been used – including by its co-author – to justify cuts to education and welfare.

But he says that we should move away from a narrative that social class determines everything and we must acknowledge the influence of genetics.

Mitchell says that this debate is potentially problematic. “There’s an idea in the US, popularised by [author] Ayn Rand, of a pure meritocracy: that I am rich because of my abilities and genetic endowments but that you are poor because you deserve to be poor.

“It can be used to support a status quo and ignore the social privilege and capital that people inherit along with their genetic capital.”

Nature vs nurture: ‘The intelligence of people of privilege is assumed ... whereas I have to constantly prove I am intelligent’

Senator Lynn Ruane grew up on a council estate in Tallaght and, at the age of 15, left school as a single mother.

She returned to education through An Cosán, a community education project founded by Katherine Zappone (now Minister for Children) and her late wife, Ann-Louise Gilligan.

She went on to Trinity College through its access programme, became president of the Students’ Union on a platform of access to education, student activism and opposing fees, and became a senator in 2016.

She is a member of the Oireachtas committee on education and skills.

“This debate can feed into a narrative whereby some classes people are perceived as superior to others,” she says.

“Intelligence is very reliant on environment, and to say it is all down to genetics ignores your family and professional background. People do well because they can more easily navigate a system which they were born into.

“When I was in school, I would never have dreamt I would be writing legislation. I know I am intelligent and can pick things up quickly, but if I had not found that pathway, I could be marked as ‘genetically weaker.

“In my job, I regularly see people of privilege where their intelligence is assumed, whereas I have to constantly prove I am intelligent. There are intelligent people from all social groups, but I know of lecturers refusing to teach students who came through a non-traditional route, such as access. Snobbery abounds.”