As a parent, I’d like to believe that I’ve played some part in crafting my daughter’s future. Maybe it is egotism, but I like to think I’ve done more for her than just fed her, watered her, provided shelter for her and footed an ever-growing electronics bill. And I like to hope that will be partly my input, my guidance that will send her out safely out into an uncertain world, armed with degrees and academic accolades ready to fight off an uncertain economy, a changing employment landscape, and abundant overseas labor.
A study carried out by scientists at Florida State University, and published in the journal Intelligence came to the following conclusion: “The way a child is parented ‘will not have a detectable effect on their IQ.”
The research provides the latest twist in a controversial field. Some previous studies have claimed that parental behavior toward their children can influence how intelligent they will be in adulthood but the Florida researchers didn’t buy this. They believed the previous results were simply hadn’t accounted for genetic transmission.
For their research, the Florida scientists examined the link between parental behavior and later-life intelligence among a nationally representative sample of youths and a second group of aged-match adopted youths who were part of the National Longitudinal Study of Adolescent Health.
The behaviors of participants’ parents were assessed, and participants completed an IQ test that measured verbal intelligence—the Picture Vocabulary Test—while at middle and high school. They completed the IQ test again when they were between the ages of 18 and 26.
The researchers say they found that—among both groups—the influence of parental behavior on child intelligence during adolescence and young adulthood was “marginal and inconsistent.”
So how do the researchers reconcile the fact that these results challenge previous research indicating that parental actions influence a child’s intelligence?
More intelligent parents are more likely to carry out activities that have previously been associated with intelligence, argue the researchers. But the activities are merely masking the genetic transformation of intelligence to their children.
This study came on the heels of another study by King’s College London researchers, published in the Proceedings of the National Academy of Sciences, that tried to quantify the relationship between genetics and academic achievement.
The scientists reviewed the educational achievement of 6,653 pairs of identical and non-identical twins to enable them to identify the degree to which traits are influenced by the environment or are inherited. It found their scores in GCSEs (high school exams in the U.K.) were three-quarters heritable but that heritability was not based on intelligence alone.
Of course, the whole definition of intelligence is a difficult one. In a recent review paper in Nature’s Molecular Psychiatry on the genetics and intelligence, the authors define intelligence as follows:
Intelligence is at the pinnacle of the hierarchical model of cognitive abilities that includes a middle level of group factors, such as the cognitive domains of verbal and spatial abilities and memory, and a third level of specific tests and their associated narrow cognitive skills.
They go on to put it in more layman’s terms:
According to one view, the core of this general intelligence factor is ‘the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience.
In the review, the relationship between intelligence and academic achievement is assumed a linear one, but at the same time it can be one thing to be able to do a cognitive task (intelligence), it’s an entirely different factor altogether whether we actually do it (leading to academic achievement). So there maybe plenty of highly intelligent children, and adults, out there who have the ‘ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience,’ especially if they are paid to take part in a study, and sat down in a room, but on their own, does that ability translate to academic achievement?
It is hard not to draw on personal experience when thinking about the issue. Right now, at this moment in time, my 10-year-old daughter is doing just fine at school. Although she’s youngest in her year, popping out in early August just before the school year cut off date, she is pretty much top of the class in math, reading and writing, and well into the advanced grade for her SAT scores. But that wasn’t always the case. In first grade, following a “year out” by our family, she was near the bottom of the class in all three of the above. If it hadn’t been for a crash course in ABCs, and reading, on our part, she would have been placed in early literacy, pulled out of everyday lessons and stigmatized, and the whole trajectory of her education might have been totally different. She certainly thought she was stupid, the teachers didn’t find a much more articulate way of phrasing it (while she was there even), and it was difficult to build her confidence or motivation. But we did. That was parental contribution for you.
Using this simple example (it’s easy to find a multitude of similar ones), does parenting have an influence on intelligence? Or does parenting, or the school environment, or other environmental factors only have an influence on academic achievement, self-esteem, and academic interest and satisfaction?
Eva Krapohl, lead researcher of the King’s College London study, said:
What our study shows is the heritability of educational achievement is much more than just intelligence — it’s the combination of many traits which are all heritable to different extents.
So the basic gist could be that parents don’t influence intelligence, beyond donating their DNA, but they can influence academic achievement. But wait a minute, Eva Krapohl said that “of educational achievement is much more than just intelligence – it’s the combination of many traits which are all heritable to different extents.” So does it all come down to genetics yet again? Is simply the way I choose to parent a function of my genes?
Is this what Professor Leon Kamin of Princeton, said in a 1995 article in the Independent was the discernible “rise of neurogenetic determinism.”
In this article, the author, social statistician Toby Andrew, bemoaned the idea that genes determine intelligence was fashionable again and argued that the role of the environment was being badly neglected. As part of his editorial, he cited that speakers from the “Biological and Social Aspects of Intelligence” conference held that year in London.
Professor Thomas Bouchard, head of a long-running twin study at the University of Minnesota, asserted in the keynote Galton address: “Since Francis Galton’s brilliant outline [of the genetic basis to intelligence], there has been a steady incremental advance. All the evidence points in the same direction and that is genetics.” Professor Bouchard claims intelligence is 70 per cent inherited, whereas Professor Plomin believes the figure is nearer 50 per cent.
Andrews then went on to quote Professor Robert Plomin, who is still a prominent figure in the debate today:
The “nature vs nurture” debate has become sterile and that, in the Nineties, the two camps have started to come together. The task today is to study how genes and environment interact, not how one takes precedence over another. Traits that are genetic need not be immutable, because the environment can be modified so that the genes never become manifest.
But it doesn’t seem like those two have really come together. The recent spate of studies would indicate that scientists don’t believe the two are interacting but that genes are running the show. Even in 1995, Plomin argued:
Quantitative measures previously thought to reflect environmental factors should now be recognized in large part to be genetic in origin as well. For example, in the past psychologists have studied the child as a passive recipient of the environment. The new insight today is that a child can actively create the environment by shaping how his parents respond to him. This, in turn, is influenced by the innate intelligence and personality of the child.
And Andrews commented:
In the model, the individual is graced with being able to shape his surroundings, but even this active element in shaping interpersonal relationships is reduced to the functioning of genes.
So, to take the example above of my daughter that means some of her academic success might simply be due to the genes she has inherited from my husband and I, both who have graduate degrees. But what of her “by no means short” stint (three years) of being the class dunce? By Plomin’s argument in 1995 could her genes have set up an elaborate ruse to get more parental attention, which then meant she then catapulted to the top of the class? I had no idea my genes were that conniving.
Hmm. And maybe my desire to want to see her sent out into the world well-qualified and enjoying learning is just a reflection of my genes too.
In truth, I don’t have much trouble accepting that I can do little for my daughter’s intelligence after having conceived her. But I personally believe that, as the King’s College study supports, my involvement can influence her academic achievement.
The intriguing question is whether this influence is also just genetically determined. In my own personal experience of two parents, five siblings and one daughter I can find plenty of examples that would suggest it is, and it isn’t. Maybe I’ll just draw comfort from King’s College researcher Krapohl’s parting shot in an interview with the Mirror:
Finding educational achievement is heritable certainly does not mean that teachers, parents or schools aren’t important.
Jane Palmer is a freelance science writer and radio journalist based near Boulder, Colorado. Follow Jane Palmer on Twitter @JanePalmerComms