Klein · Journal of experimental psychology. General 2001 · Randomized controlled trials (2 experiments) · n=172

Expressive writing can increase working memory capacity.

Cited 344 times in the scientific literature.

Level 2 - randomized trial

Individual randomized controlled trials evaluating behavioral interventions over multi-week follow-ups.

PubMed 11561925 · doi:10.1037//0096-3445.130.3.520 · record verified 2026-08-29

What was done

Across two semester-long experiments, college students were randomized to different writing tasks to test the effect of emotional disclosure on working memory (WM) capacity. In Study 1, 71 freshmen were assigned to write about thoughts and feelings regarding transitioning to college (n = 35) or a trivial topic (n = 36), with WM assessed 7 weeks later. In Study 2, 101 students were assigned to write about a negative personal experience (n = 34), a positive experience (n = 33), or a trivial topic (n = 34), with outcomes tracking WM improvements and intrusive thinking.

What was found

In Study 1, freshmen writing about their college transition showed larger WM gains after 7 weeks than controls; higher usage of cause and insight words was associated with larger WM gains. In Study 2, writing about negative personal experiences produced greater WM improvements and larger reductions in intrusive thinking compared to writing about positive experiences or trivial topics. The abstract reports no exact numeric scores, variances, or p-values.

Why it matters

These findings suggest that disclosing and processing stressful experiences through writing can diminish intrusive thoughts, freeing cognitive working memory capacity for other tasks.

Limits

The abstract provides directional findings without exact effect sizes, standard deviations, or p-values. The samples were small (n = 71 and n = 101) and restricted to university students, limiting generalizability to broader populations or clinical cohorts.

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