Students who are likely to become nervous could ease this anxiety and improve their performance if they write about their worries 10 minutes before the exam.
The study found that students who were prone to test anxiety improved their high-stakes test scores by nearly one grade point after they were given 10 minutes to write about what was causing them fear.
The writing exercise allowed students to unload their anxieties before taking the test and accordingly freed up brainpower needed to complete the test successfully - brainpower that is normally occupied by testing worries, explained the study's senior author, Sian Beilock.
They also predicted that just one round of writing immediately before a big event would be sufficient to curb choking and boost students' test scores.
To test those ideas, researchers recruited 20 college students and gave them two short math tests. On the first test, students were told simply to do their best.
Before the second test, researchers created a situation designed to produce stress, by saying students who performed well would receive money and that other students were depending on their performance as part of a team effort.
Students also were told that their work would be videotaped, and that math teachers would review it.
Half of the students then received 10 minutes to write expressively about their feelings about the upcoming test (expressive writing group), and the other half was told to sit quietly (control group).
"The expressive writing group performed significantly better than the control group," the authors wrote.
"Control participants 'choked under pressure,' showing a 12 percent accuracy drop from pre-test to post-test, whereas students who expressed their thoughts before the high-pressure test showed a significant 5 percent math accuracy improvement," the authors added.
The findings appeared in the Jan. 14 issue of Science.