Your genes affect which university you go to but that’s no surprise.
Presentation
NATURE OR NURTUE?
READING.
www.newscientist.com/article/dn10430-child-abuse-nature-or-nurture/
Article 1.
Child abuse: nature or nurture ?
LIFE 2 November 2006
By Roxanne Khamsi
Monkeys that are abused as infants develop a specific brain change that makes them more likely to mistreat their own offspring, a new study shows.
The findings may help explain why child abuse in humans often perpetuates from one generation to the next, the researchers say.
Dario Maestripieri at the University of Chicago in Illinois, US, and colleagues found that baby rhesus monkeys that endured high rates of maternal rejection and mild abuse in their first month of life produced less of the brain chemical serotonin. Low levels of serotonin are associated with anxiety and depression and impulsive aggression in both humans and monkeys.
The team followed a group of newborn rhesus monkeys with mothers that abused and rejected them. They also studied eight newborn monkeys taken from their birth mothers and placed with abusive ones instead.
Passed down
Analysis of the monkeys’ brain fluid revealed that those reared by abusive mothers or abusive foster mothers had 10% to 20% less serotonin than monkeys who had grown up without maternal abuse. This supports the idea that the drop in serotonin results from mistreatment, rather than a genetic predisposition, says Maestripieri.
Researchers followed the female monkeys into adulthood and found that about half of them abused their own offspring. Those that did abuse their offspring were the ones with the lowest serotonin levels.
The new findings could explain why people who are abused as children may be more likely to be abusive themselves as adults, Maestripieri suggests.
Skills lessons
The study findings suggest that it may be helpful to give abused children antidepressant drugs that raise their serotonin levels, but the prescribing of such drugs to children has become controversial, since some research suggests they may increase suicidal thoughts in youngsters. And experts stress that a drug will not erase the various, long-lasting effects of abuse.
“Chemicals alone aren’t going to fix the problem,” agrees Karen Costa, clinical director of the Child Abuse Prevention Association in Independence, Missouri, US. She explains that therapy plays a key role in treating victims and that parenting skills lessons can help prevent abusive situations occurring in the first place.
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Maestripieri agrees that low levels of serotonin alone do not fully explain abuse, which is a complex behaviour. Even if abusive people are shown to have low levels of serotonin, this does not mean they cannot stop their abusive behaviour, he points out. “Biology is never an excuse for anything.”
Journal reference: Behavioral Neuroscience DOI: 10.1037/0735-7044.120.5.1017)
Article 2.
Nature more than nurture determines exam success
www.newscientist.com/article/dn24745-nature-more-than-nurture-determines-exam-success/
A controversial study on twins claims to provide strong evidence that genetic inheritance has a bigger impact on exam success than schooling and parenting. Does this mean that a child’s educational fate may be sealed at conception? Or that a child’s genes might be analysed to determine how they are taught? New Scientist finds out.
What did the study actually discover?
The study was designed by Robert Plomin of the Institute of Psychiatry at King’s College London and his colleagues, to tease apart the impacts of genes and the environment on educational achievement.
The key objective was to see how exam scores varied from the national average depending on whether twins had the same genetic make-up, which identical twins do, or shared only half of their genes, which is true for non-identical twins.
Since each set of twins in the study was assumed to share the same environment and schooling, the researchers were able to separate the effects of genetics and education on their academic success.
It turns out that nature trumps nurture. After analysing the GCSE results of 5474 pairs of twins – 2008 of them identical – the team found that genes accounted for 52 per cent of the differences between exam scores. A shared upbringing accounted for only 36 per cent of the differences, with the remainder accounted for by environmental factors that weren’t shared, such as each twin having a different teacher.
Did the result hold true for every subject?
Overall, across the three core subjects of English, mathematics and science, achievement was 58 per cent determined by genetics. Individually, achievement was 52 per cent down to genetics for English, 55 per cent for maths and 58 per cent for science.
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The figure for humanities was lower at 42 per cent. This was a surprise to Plomin because, traditionally, excellence in humanities subjects such as art or music is considered to be “handed down” from parents, whereas science is considered a product of the teaching environment.
Does this mean that the die is cast for children whose parents haven’t done well in their exams?
Not according to Plomin. “Finding a genetic influence does not mean we cannot do anything about it,” he says. “Marginalisation of the ‘less gifted’ does not at all follow from finding genetic influence on educational achievement. If anything the opposite is true – we need to provide more resources for those who need the most help.”
So, should we change our education systems based on these results?
Plomin says it is far too early to say, but the findings should inform debate on how education is delivered and structured. “We believe in an evidence-based education, and we don’t yet know what works best,” he says.
Plomin favours an educational system that gives extra resources to struggling children to optimise their genetic potential. He thinks that each child’s genetic make-up prompts them to react differently to their schooling so, ironically, attempts to level out differences in achievement by providing a uniform education system – like the UK National Curriculum – actually achieves the opposite. For example, children whose genetics give them the motivation and aptitude to read early zoom ahead of others.
But Plomin argues that children of all abilities can achieve this, provided they receive extra help to do so. “One strong implication of recognising and respecting genetically driven differences between children is to personalise education as much as possible, rather than imposing a ‘one-size-fits-all’ approach,” he says.
However, even if it were possible to analyse every child’s genetics, no single genes for IQ or educational achievement have yet been identified, says Sarah Norcross of the Progress Educational Trust, a UK charity that promotes debate on genetics and reproduction.
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Most studies so far, including those by Plomin, have found that educational achievement is influenced by a combination of thousands of genes. “We don’t even understand the genetics of height yet, which is very easy to measure,” says Norcross. “So we are light years from applying this type of thing to education.”
What do others make of the findings?
Some researchers are sceptical, including Steven Rose of the UK’s Open University, who is critical of twin studies and of attempts to find genes linked with intelligence. He says that twin studies are “notoriously subject to difficulties of interpretation”.
For instance, the unusual upbringings of identical twins – often wearing exactly the same clothes or being confused with one another – constitute an environmental impact that could be overlooked when comparing them with fraternal twins. But he agrees with Plomin that child-focused rather than rote education is the way forward. “In an ideal school environment, individual aptitudes should be encouraged, but you don’t need to, and nor would it be practicable to sequence a child’s genome to discover what these aptitudes might be,” he says.
“Some people might take the results negatively, as if our potential in life is limited by our genetic code,” says Paul Thompson of the University of Southern Cali
Article 3.
Your genes affect which university you go to but that’s no surprise.
www.newscientist.com/article/2183014-your-genes-affect-which-university-you-go-to-but-thats-no-surprise/
A large study of twins has found links between genes and which university people go to, but any behavioural traits in people arise from a complex interplay of nature and nurture.
By Clare Wilson
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