I’ve heard there is a gene that gets you into Oxford – can it really be true?
Hardly. A large study of 3000 pairs of UK twins has found that, like intelligence, your chance of getting into a good university is partly heritable. If your twin gets into the University of Oxford, for instance, you are more likely join them if they are your identical twin, with whom you share all your DNA, than if they are just your fraternal twin, where you share half. Doing this suggests that 57 per cent of the “quality” of your university is down to your genes, say Ziada Ayorech of King’s College London and colleagues in a study published today (Scientific Reports, DOI: 10.1038/s41598-018-32621-w).
What does “university quality” mean?
The team used existing university league tables as a measure of quality, although sceptics might argue this doesn’t take account of the possibility that different institutions could suit different people for reasons other than their academic prestige – or even that plenty of intelligent people choose not to go to university at all.
So could a genetic test tell you which university your child could get in to?
Fortunately not. The same team also looked at the DNA of a different 3000 people and could only identify up to 5 per cent of the genes that seemed to be linked to universities. Thanks to this “missing heritability” we’re a long way off from making genetic predictions about university acceptance, or any other complex behavioural traits.
Do we know how much of a person’s intelligence is determined by their genes?
Previous research has suggested between 50 and 80 per cent of the variation in people’s IQ is inherited. As intelligence affects school exam results and they in turn influence which university you go to, it’s unsurprising that genes may be linked to university destination too. But the team tried to remove the effects of intelligence from the analysis by removing the impact of exam results on university entrance using statistical techniques. When they did this, they found that genes were still behind 47 per cent of the variation in university quality, suggesting that they do affect university destination in ways other than shaping your intelligence.
So is it case closed?
Not necessarily. Intelligence genes might influence your university through other mechanisms than exam results, for instance by affecting how impressive an application form you write and how well you do at interview.
Isn’t the whole concept of IQ falling into disrepute anyway?
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Not really. Certainly there is a shameful history of people using IQ tests to justify racist and sexist attitudes without taking societal inequalities into account. But that doesn’t mean the tests themselves are flawed. Countless studies have found that people with higher IQ on average do better at school, get better jobs, and earn more money in life. Whatever it measures, it’s something interesting, says Stuart Ritchie, also of Kings College London, who wasn’t involved in the research.
So our fate is determined at birth after all?
Not at all. If half the variation in intelligence – or university destination – comes down to our genes, the rest must be down to our surroundings. That could include how much encouragement children get from their family and friends, whether their parents went to university, family wealth, and the quality of teaching at their school. Governments can help level the playing field, for example by funding early-years education so children from poorer households don’t start school behind.
So intelligence, like all complex behavioural traits, comes from an interplay of genetic and social factors?
Go to the top of the class.
Article 4.
Are murderers born or made?
www.bbc.com/news/magazine-31714853
Murders are tragic but rare. But what drives some people to kill? Michael Mosley has been looking into research exploring the minds of murderers.
In the 1870s Dr Cesare Lombroso, sometimes called the father of scientific criminology, was studying criminals imprisoned in Turin.
He became convinced that criminals are a step back down the evolutionary ladder, a reversion to a primitive or subhuman type of man. He decided, after years of study, that you could tell a criminal by the shape of their face and the excessive length of their ape-like arms.
"A criminal's ears," he wrote, "are often of a large size. The nose is frequently upturned or of a flattened character in thieves. In murderers it is often aquiline like the beak of a bird of prey."
Sadly, spotting potential murderers turned out to be nothing like as simple as Dr Lombroso claimed and his "scientific" findings were soon discredited. But this was the beginning of a search that has continued for more than a century - to find out if criminals, and in particular murderers, have different brains to the rest of us.
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The invention of functional brain scanning in the 1980s revolutionised the understanding of what goes on inside our heads. The first scanning study of murderers was carried out in California by British neuroscientist Prof Adrian Raine. He was attracted to the Golden State not by the beaches but by, as he put it, "the large numbers of very violent and homicidal individuals".
Over the course of many years Raine and his team scanned the brains of numerous murderers and nearly all showed similar brain changes. There was reduced activity in the pre-frontal cortex, the area of the brain which controls emotional impulses, and over activation of the amygdala, the area which generates our emotions.
So it seems that murderers have brains that make them more prone to rage and anger, while at the same time making them less able to control themselves.
But why does this happen?
Raine's studies suggest that part of the reason may be childhood abuse, which can create killers by causing physical damage to the brain. The pre-frontal cortex is especially vulnerable.
One of the prisoners that Raine scanned was Donta Page, a man who brutally murdered a 24-year-old woman when she caught him breaking into her home. As a baby Page was frequently shaken by his mother, and as he got older the abuse got worse. His mother would use electrical extension cords, shoes, whatever was handy. These were not once a year beatings, they were beatings that occurred almost daily.
"Early physical abuse, amongst other things could have led to the brain damage, which could have led to him committing this violent act," Raine says.
But only a small proportion of those who have a terrible childhood grow up to become murderers. Could there be factors that predispose us to murder?
A breakthrough came in 1993 with a family in the Netherlands where all the men had a history of violence. Fifteen years of painstaking research revealed that they all lacked the same gene.
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This gene produces an enzyme called MAOA, which regulates the levels of neurotransmitters involved in impulse control. It turns out that if you lack the MAOA gene or have the low-activity variant you are predisposed to violence. This variant became known as the warrior gene.
About 30% of men have this so-called warrior gene, but whether the gene is triggered or not depends crucially on what happens to you in childhood.
Jim Fallon, professor of psychiatry at the University of California, has a particularly personal interest in this research. After discovering a surprisingly large number of murderers in his family tree he had himself genetically tested and discovered he had an awful lot of genes that have been linked to violent psychopathic behaviour.
As he puts it: "People with far less dangerous genetics become killers and are psychopaths than what I have. I have almost all of them"
But Jim isn't a murderer - he's a respected professor.
His explanation is that he was protected from a potentially violent legacy by a happy childhood. "If you've the high-risk form of the gene and you were abused early on in life, your chances of a life of crime are much higher. If you have the high-risk gene but you weren't abused, then there really wasn't much risk. So just a gene by itself, the variant doesn't really dramatically affect behaviour, but under certain environmental conditions there is a big difference".
So it seems that a genetic tendency towards violence, together with an abusive childhood, are literally a killer combination - murderers are both born and made.
We now have a far more sophisticated understanding of the complex interactions between the social and the biological factors that predispose people to violence. But what can we do with that knowledge?
Research is focusing on ways to reduce violent behaviour and there is good evidence that teaching families who are at risk positive parenting skills is effective at improving impulse control.
The hope is that now we know so much more about the causes of murderous behaviour we can spot the early warning signs and intervene before it's too late.
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