Handling stress: a biological view

PUBLISHED : Monday, 19 August, 2013, 12:00am
UPDATED : Monday, 19 August, 2013, 9:15am

Results of the International General Certificate of Secondary Education (IGCSE) exams were released last week. Whether students did well or not, there's a benefit. Their results will provide admission tutors evidence of their academic ability that should support the grades they present to colleges for admission.

Students who didn't fare as well can view the exams as practice for the IB or A-levels, whose results will count towards college admission.

The people who perform best in normal conditions may not be the same people who perform best under stress
Adele diamond, university of british columbia

When viewed that way, the exam itself has a purpose.

"Children benefit from competition that they have prepared for intensely, especially when viewed as an opportunity to gain recognition for their efforts and improve for the next time," says Dr Rena Subotnik, director of the Centre for Gifted Education Policy for the American Psychological Association.

The reasons for a student's success can be many, but intense preparation is chief among them. Stress is always a factor when sitting exams, leading some of my students to ask a common question: are some students hard-wired to handle stress better than others? Why do some students perform better under stress and why are others paralysed by it?

IGCSE students who have studied enzymes and genes in biology will understand the significance of the enzyme Catechol-O-Methytransferase (COMT) as a major step in how catecholamines - which are released during stress - are broken down in the brain. One of these catecholamines is dopamine, a chemical that transmits information through the nervous system. The COMT gene codes have an effect on removing dopamine, which, in turn, weakens the electronic signal.

A study by Dr Chang Chun-yen, director of the science education centre at National Taiwan Normal University in Taipei, compared scores on the National Basic Competency Test of 779 young teenagers from four schools with each student's COMT genetic make-up.

Students with two copies of a mutation called Met-158, which clears dopamine more slowly, tend to have a better working memory and higher verbal IQs than students with one or two copies of a mutation called Val-158, which clears dopamine from the synapses faster.

Researchers have consistently found that under normal conditions, people with the slow-acting enzyme have an advantage in reasoning, problem-solving and concentration. This advantage appears to increase with the number of years of education; however, these students also display more anxiety, depression and emotional vulnerability in response to stress or educational adversity. In exam situations, they performed much worse in science and social science subtests.

It's interesting that in high-stakes exams, when the prefrontal cortex of the brain is flooded with dopamine, Taiwanese students with the Val-158 mutation performed an average of 8 per cent higher on the national exam the Basic Competency Test.

Adele Diamond, a professor of neuroscience at the University of British Columbia in Canada, concludes: "The people who perform best in normal conditions may not be the same people who perform best under stress."

People born with the fast-acting enzymes "actually need the stress to perform their best. They benefit from that surge in dopamine; it raises the level to optimal, increasing their ability to concentrate and solve problems."

While the researchers acknowledge that a single gene variation such as COMT is probably "only one of many factors in influencing a complex trait such as anxiety", more studies are suggesting that specific variants in the COMT gene play a role in whether a student is a "warrior" or a "worrier" at exam time.

Anjali Hazari teaches IB and IGCSE biology at the French International School