24/04/2014 11:14 BST | Updated 24/06/2014 06:59 BST

What Do Exams Prove?

Heading into exam season, it's hard not to be aghast at the pressure and panic that prevails in households this time of year. My daughter alternates between grim perseverance and limp hopelessness while many of her peers surrender to hysteria at the slightest challenge. While doing their best to support their children though the ordeal, sane parents must stop and ask: do these exams prove anything?

The government's line is that they do. Education secretary Michael Gove and his trusted ally Elizabeth Truss argue that they do. "If we know tests are rigorous and they require application to pass," says Gove, "then the experience of clearing a hurdle we once considered too high spurs us on to further endeavours and deeper learning."

This argument is based on the American cognitive scientists Daniel T. Willingham who observed that kids enjoyed learning if they experienced 'the pleasurable rush that comes from successful thought.' But that rush of thought isn't nearly the same as sitting an exam, which mostly isn't about thinking but searching and repeating old thoughts.

Gove of course was good at exams so of course he thinks they measure what matters. But whether you excel or collapse at exams is significantly determined by your genes.

The COMT (catechol-O-methyl transferase) gene regulates the amount of dopamine in the pre-frontal cortex in the brain, where we make decisions, plan and resolve conflicts. One variant of COMT removes dopamine slowly; another variant does it fast. Dopamine levels increase with stress; enough helps you rise to the occasion but too much becomes overwhelming. So students with the slower variety of COMT typically find it easer to think if they are not under stress. Those with the faster variety may seem a little laid back but, under stress, they cope better. Some scientists distinguish between the two genetic stress responses as 'worriers' and 'warriors' but the key point about them is that they both excel - albeit in very different environments. Hence the paradox that hardworking students may fall apart in exams while the ones who never handed in their homework on time ace tests. What exams reveal most clearly is not intellectual or creative capacity - but a very great deal about how good you are at exams.

The research into COMT was primarily conducted in Taiwan, which traditionally placed great emphasis on a single exam - the Basic Competency Test - taken by children when they are fourteen. In essence, this was their equivalent of the 11-plus. Applying their In essence, this was their equivalent of the 11-plus. Applying their genetic insights to real-world testing confirmed the hypothesis that this kind of high-stakes test identified great exam takers but was less helpful in building or identifying intelligence. From this year, Taiwan will no longer require the exam.

You could argue that being good at exams - for whatever reasons - is useful in life but the correlation has never been proved and few employers believe that. Google's more interested in the subjects you've taken and how far you've persevered with hard subjects. Other employers care about the narrative arc of your achievement: are you someone who keeps improving? Many look for evidence of creativity and the ability to improvise solutions to problems while every company on earth is desperately searching for those who actually like working with other people. None of this, of course, is revealed by exams.

Experts aren't that much better. Sir John Gurdon, who won the Nobel Prize for research into genetic cloning was castigated by his biology teacher at Eton. The head of St Paul's Girls School in London sternly advised me that I was not university material. I later learned that I'd been accepted into Cambridge because my college was sick and tired of the hothouse plants from the school who were great at exams but nothing else.

None of this means kids shouldn't work hard at school. Developing a love of learning is a gift for life. But exams will never capture that - and they go a long way towards destroying it.