Special to LitSite Alaska

As other authors on LitSite Alaska have noted, there is now credible scientific evidence that writing about stressful experiences can boost immune function, decrease the likelihood of catching some infectious diseases, and reduce the symptoms associated with other illnesses involving the immune system.

Recent work in my laboratory suggests that writing can also improve attention, or the ability to concentrate, which cognitive psychologists call working memory. Furthermore, these improvements in the ability to concentrate translate into real world outcomes, like better college grades. In this report, I'll explain how psychologists define and measure working memory capacity (abbreviated as WM), then I'll describe the experiments Adriel Boals and I conducted, and then I'll give some suggestions about how people could use the writing technique on their own.

First, a little background on why psychologists are interested in working memory capacity and how it can be measured.

How We Study Working Memory Capacity

Kitty Klein kayaking with her dogs, Gordo and Keri.

In our research, we used Randall Engle's definition of working memory capacity -- the ability to keep our attention focused in the face of distraction or interference. Working memory is an important predictor of performance on many complex tasks, like driving a vehicle or piloting an airplane. As Engle and others have shown, people with higher working memory capacity also do better on standardized college admission tests, intelligence tests and reading comprehension tests. These relationships should come as no surprise, because the ability to focus attention on relevant information is needed to do well on almost any cognitive task one can name. To measure this capacity we used a test that requires people to solve arithmetic equations while at the same time remembering a list of words. The more words remembered, the greater one's working memory capacity.

Our Research

In two experiments, the first step was to measure our participants' working memory capacity using a standard laboratory task. Next, we randomly assigned these participants to write about different topics. In the first experiment, we asked one group of first semester freshmen to explore their deepest thoughts and feelings about coming to college (the expressive writing group). The other group was asked to write about how they had spent the previous day (the control group). Everyone wrote for 20 minutes, at three different sessions, spread over a two-week period. After the third writing session we measured WM again. Six weeks later, everyone returned to the lab for a final measure of their WM. We then looked at changes in the WM scores. The data indicated that the freshmen asked to write about coming to college experienced a 6% gain in WM while the group who wrote about their day had an average gain of 3%. We used a text analysis program to analyze the essays to see if people who wrote expressively used words differently than the control group. As in previous research in which health benefits were of interest, the expressive writers showed increases in the use of words related to understanding and reasoning across the essays. The greater these increases, the greater the increases in their ability to focus their attention. Finally we looked at the grade point averages for the students for the semester of the experiment, which was their first, and the following spring semester. People who showed the greatest increases in WM capacity on the laboratory test had better grades for the semester of the experiment and even better grades the next spring.

In the second experiment, we used similar procedures for measuring WM and timing the experimental sessions, but we had three different writing groups. At the first session, everyone gave us a brief description of a negative personal event and a positive personal event and told us how often they had unwanted thoughts about these events. Then we assigned people to their topic, either the negative personal event they had described, or the positive personal event, or about how they spent their day. The results from this experiment were more striking than those in our first study. People who wrote about a negative event showed an average of an 11% increase in WM capacity. People who wrote about a positive experience had an average 4% improvement in their WM test scores and people who wrote about their daily activities had an average 2.5% improvement. Again, the greater the increase in WM capacity, the greater the improvement in grade point averages. We also found that the greater the decrease in unwanted thoughts about the negative experience, the greater the improvements in attentional capacity.

In the two experiments described above, people who wrote about a stressful experience showed improvements in their ability to concentrate, measured by a standard test of working memory capacity. Our explanation for this finding is that our memories for negative or traumatic experiences are often fragmented and disorganized, like pieces of a nightmare. When we write about these experiences, our memories gradually become more coherent and story-like, allowing us to understand what happened and better deal with the emotions surrounding the experience. Once we are able to 're-package' our stressful memories into a story, isolated fragments of these memories are less likely to come unbidden to our conscious minds. We do not forget traumatic experiences but expressive writing can transform our memories so that we are not continually upset by unwanted thoughts about traumatic or stressful events.

How To Write Expressively

The instructions we used in our experiments are based on those developed by Dr. James W. Pennebaker, who was the first researcher to demonstrate that expressive writing could affect physical health. Here are the instructions:

Kitty Klein and Adriel Boals.

"For the next 20 minutes your task is to write about your very deepest thoughts and feelings regarding any events that have had a negative impact on your life. The negative impact might be an actual change in your circumstances or it might be an emotional change that has left you feeling sad, ashamed or hurt. In your writing, try to let yourself go and write continuously about your emotions and thoughts related to these events. Describe the facts and feelings of your experiences. Write about the experience in as much detail as you can. Do your best to "tie it all together" at the end of the writing. Remember you are writing only for yourself. Don't worry about grammar or spelling. The important thing is that you really let yourself go and dig down to your very deepest thoughts and feelings about the negative event."

More Information

Our experiments were published as:

• Klein, K. & Boals, A. (2001). Expressive writing can increase working memory capacity. Journal of Experimental Psychology: General, 130, 520-533.
• To read more about working memory and attention, see
• Engle, R. W., Kane, M. J. & Tuholski, S. W. (1999). Individual differences in working memory capacity and what they tell us about controlled attention, general fluid intelligence and functions of the prefrontal cortex. In A. Miyake & P. Shah (Eds.), Models of Working Memory: Mechanisms of Active Maintenance and Executive Control (pp.102-131). Cambridge, UK: Cambridge University Press.
• To read more about the effects of expressive writing on health and cognition, see the new book,
• Lepore, S. & J. Smyth (2002). The Writing Cure: How expressive writing promotes health and emotional well-being. American Psychological Association: Washington, DC.
• To read more about how to use expressive writing yourself, see
• Pennebaker, J.W. (1997). Opening Up: The Healing Power of Expressing Emotions, revised edition. New York: Guilford Press.
• Carpenter, Siri. (2001). "A New Reason for Keeping a Diary: Research Offers Intriguing Evidence On Why Expressive Writing Boosts Health." Monitor on Psychology, 32.