Two laboratory and two randomized field experiments tested a psychological intervention designed to improve students' scores on high-stakes exams and to increase our understanding of why pressure-filled exam situations undermine some students' performance. We expected that sitting for an important exam leads to worries about the situation and its consequences that undermine test performance. We tested whether having students write down their thoughts about an upcoming test could improve test performance. The intervention, a brief expressive writing assignment that occurred immediately before taking an important test, significantly improved students' exam scores, especially for students habitually anxious about test taking. Simply writing about one's worries before a high-stakes exam can boost test scores. F or many students, the desire to perform their best in academics is strong. Consequences for poor performance, especially on exams, include poor evaluations by mentors, teachers, and peers; lost scholarships; and relinquished educational opportunities. Yet despite the fact that students are often motivated to perform their best, the pressure-filled situations in which important tests occur can cause students to perform below their ability instead (1).The expression "choking under pressure" is used to describe what happens when people perform more poorly than expected given their skill level when there are large incentives for optimal performance and negative consequences for poor performance (2). Choking is a serious problem given that poor exam performance affects students' subsequent academic opportunities. It also limits potentially qualified students from participating in the talent pool tapped to fill advanced jobs in disciplines where the workforce is dwindling [e.g., science, technology, engineering, and mathematics workforce in the United States (3)]. Here we demonstrate how a 10-min. pre-exam intervention, derived from psychological theories of stress and performance, can prevent choking and enhance exam scores, particularly for students who habitually become anxious in testing situations.Several studies have shown that, when students feel an anxious desire to perform at a high level [i.e., performance pressure (4)], they worry about the situation and its consequences (5, 6). These worries compete for the working memory (WM) available for performance. WM is a shortterm memory system involved in the control and regulation of a limited amount of information immediately relevant to the task at hand (7). If the ability of WM to maintain task focus is disrupted because of situation-related worries, performance can suffer (8).Worries not only occur in intense academic situations but are a major component of depression and other clinical disorders (9). Expressive writing, in which people repeatedly write about a traumatic or emotional experience over several weeks or months, has been shown to be an effective technique for decreasing rumination in depressed individuals (10). Writing may alleviate the burden t...