Twins
study reveals influence of genes and environment on academic achievement.
Sally Larsen: People jump straight to that when we talk about twin studies and
genetics, they jump to this idea of genetic essentialism, that somehow you
can't change your genes and so there's no point trying, and that's really not what twin studies are telling us. So twin studies
are telling us about potentially the proportion of an outcome that could be
attributed to genetics in this particular context at
this time. So they tell us what is happening now, but
not about potential and what could be. And so it's
really important to have that message clearly, that even if something is partly
heritable, the fact is that that doesn't mean it's not changeable.
Robyn Williams: Genes are not destiny. Sally Larsen from the University of New
England on their huge twin study about schooling. Also
in this Science Show on RN, how to plan for driverless
transport, especially in a Estonia. I thought you'd never ask. And how to
unscramble an egg, and why.
So as we contemplate the struggle public schools in Australia have in
recruiting pupils and teachers, and as so many go private, despite the
financial strain, it's worth thinking about that huge piece of research at
Armidale. This is Dr Sally Larsen, who lectures at the School of Education
there.
Now, 2,700 families provided twins. Were some
identical twins and some unidentical?
Sally Larsen: Yes, so we have about 40% identical twins and about 60%
non-identical twins. And of the non-identical, it's a mix of both girls, both
boys and some boy-girl pairs.
Robyn Williams: And they stayed with you for ten years, did they?
Sally Larsen: So overall it's been ten years, but the families, around about
seven years.
Robyn Williams: Now, many of us will think that life, going to school and studying
and absorbing all these things is so complex; it depends on whether you mucked
up, whether you concentrated, whether you were well behaved, whether you went
to a posh school, spent lots of money on private education and all that sort of
thing. So many variables. But what did you find overall?
Sally Larsen: I think the main finding overall is that school achievement is
like a balance of genetic influences and environmental influences. We're
looking over time, and what tends to happen is that shocks in the environment
will tend to balance out. So, one of the things that's good about twin studies
is that you can look at the similarities between twins or the differences
between twins. And notwithstanding the environmental things that we think might
make a difference, those things might make a short-term difference, but over
time they tend to wash out.
Robyn Williams: But what about going to a very posh school for a lot money, or the local kind of bog-ordinary public school?
Sally Larsen: Yeah, and that's another one of those things that people really strongly believe will make a huge difference to the
lives of their kids. One of the studies that we've done in this particular project, we looked at the differences between
groups of kids going all the way through from year three to year nine in public
schools, and all the way through from year three to year nine in private
schools. And what we found was that there was really no difference in the
amount of progress that students made, notwithstanding the marketing around
private schools being better quality. So that's one instance of where something
that's in the environment is potentially not having the effect that we think it
is.
Robyn Williams: Do you mean all those listeners (and we've got lots of them) who
are spending $30,000, $35,000 more per annum on either Bunty or Darren are
wasting their money?
Sally Larsen: Well, I think that's just up to families to decide really. I think
one thing about studies like this, it gives us information on average. So on average what happens when we look at big populations
or big groups of students, and so those averages show that there's lots of
variability between students. But if we look at on average the progress,
there's no differences in progress over time. Having said that though, for
individual students, different school environments might suit them better, they
might feel that a particular school environment suits that student for their particular progress, and that's something that twin studies
can't necessarily tell us about.
Robyn Williams: No, but if you had a collection, and I'm sure you did in your
figures, of one twin who went to a private school and one who did the public
course, in general what did you find? Who did better?
Sally Larsen: I think, in general, particularly for identical twins, there'd be
very little difference at the end of their schooling career, that
notwithstanding those different schools, that that wouldn't make a great deal
of difference. And we did talk to some parents of identical twins, and these
identical twins who had done really differently at
school, so were persistently quite different in their reading or numeracy
results, and different schools attended often came as a consequence of that
difference rather than a cause. So parents could identify differences in
personality between identical twins that they had observed since the twins were
very small, or differences in interests, or on occasion one twin would have had
some kind of medical problem that the other twin didn't, and those were the
sorts of things that parents observed had caused the differences in academic
achievement, and that in those cases sometimes twins did go to different
schools. But for the large majority of the twins, even
if they've attended different schools or been in different classrooms,
particularly identical twins come out the end very similar.
Robyn Williams: Very similar indeed. Well, one wonders, if you've got identical
twins and they seem to have different personalities as they're growing up, it
just shows you how complex the influences might be, because they're
all…wherever they are, even if they are on the other side of the room, the same
room, they're having a different experience. So those sorts of things do
impact.
Sally Larsen: Yes, absolutely. And as I've said, twin studies will give you information
about averages, but for those individual perceptual experiences, we do know
from twin studies that twins, even if they're in the same objective
environment, say they're in the same family or in the same school classroom,
they can experience that environment differently. And so
we can only find that out by actually asking the twins themselves. So other
twin studies have done this, we didn't get the opportunity to do that, but it
is a phenomenon in twin studies that even though we say we've provided the same
environment to these twins, why have they turned out differently, sometimes
that's differences in perception that are really hard
to pin down.
Robyn Williams: Now, you have no other comparison, as far as I can tell, for a
study in Australia, but overseas they've done similar sorts of things. Have
they reached the same conclusions as you have?
Sally Larsen: Largely yes, they do find similar conclusions to what we find.
Particularly there's a big study in the UK called the Twins Early Development
Study, and we do find similar results to them in terms of academic achievement.
So what we find is that on average, say, for example,
reading might be 60% heritable, and so people when they hear that figure and
they see summaries of this research that shows that different locations come
with the same sorts of results, they sort of jump immediately to, well, it's
genes and I can't do anything about it. But the thing that I've discovered
about twin studies along the way is that heritability statistic doesn't necessarily
mean it's inherited.
Robyn Williams: Hang on! That was a conjuring trick.
Sally Larsen: Yes, I know, and it's a terminological problem. And that's a
problem with a lot of scientific domains, they have this specific terminology
that's in layperson language, and it doesn't mean the same thing.
Robyn Williams: What do you then decide…now, I've made you over the last few
seconds Minister for Education, okay, you have total control now of the
development of, let's say, secondary education in Australia for the next 20
years. What would you recommend?
Sally Larsen: I think one thing we have written about in terms of policy is the
idea of how do we support students that struggle with academic domains? And so what we see often is that policy will say, all right,
we'll provide funding to schools if they have a proportion of students with
learning difficulties or learning disabilities. Often that funding doesn't go
directly towards the student. So in terms of
supporting students with learning difficulties, it's probably going to be more
effective to direct the funding to the student rather than the school, because
if you do a school-level intervention, say you go in and you say, okay, we're
going to get lots of iPads and that's going to help students with learning
difficulties, it probably won't. So what you need to
do is think about how you can intervene for those specific students, depending
on what their learning difficulty or disability is. Now, that's really
complicated because it's quite expensive to do. But in terms of supporting
students with learning difficulties, that's something we've written about in
this study.
Robyn Williams: Does that make sense to you as an ex-teacher?
Sally Larsen: It certainly does, yes, because as a school
teacher you're teaching a class of students, you might not have the
personal resources or the time to then go and support those students who are
struggling to the extent that you can. So additional support for students that
require additional support would be super, super helpful.
Robyn Williams: Dr Sally Larsen with a glance of that huge twin study just
published by the University of New England. So the
message is fund your teachers and public schools to get results, and genes are
not destiny. Much more in that report.
Does a public or private school guarantee
better student success? How do a student’s genes interact with factors
thought to be important in academic achievement such as preschool education,
sleep, diet and technology? Researchers at the
University of New England have been investigating these questions in a study of
2,762 twins, triplets, and non-twin siblings over ten years. The Academic
Development Study of Australian Twins has provided insight into the factors
that contribute to educational achievement – and the extent to which our genes
influence them. Project manager and lecturer Sally Larsen outlines some key
findings.
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