Write Your Secrets: What James Pennebaker Discovered About Expressive Writing

Confession does wonders for the body. For thousands of years, humans have incorporated the practice into religious rituals, therapy groups, secret diaries, and more – even sharing their innermost thoughts with strangers.

Social psychologist James Pennebaker was studying the body’s physiological response to stress when he stumbled on a confession-related phenomenon that sparked decades of groundbreaking research: the polygraph confession effect.

James Pennebaker had been invited to give a series of talks to top-level polygraphers working for the FBI and CIA. In late-night conversations following the events, these experts captured Pennebaker’s interest with similar stories. A bank vice-president, for example, showed intense physiological stress while being questioned. When he broke down and confessed to embezzlement, however, he became extraordinarily relaxed. Many polygraphers had made the same observation – even while facing severe consequences, individuals felt liberated after confessing their actions.

Through the 1980s, Pennebaker developed research supporting the idea that secrets contribute to physical illness. Specifically, he discovered that people who experienced trauma and kept it secret were most likely to have health problems. This discovery led Pennebaker to launch his well-known studies using expressive writing. “If keeping a secret about a trauma was unhealthy,” he writes, “it made sense that having people reveal the secret should improve health.” As a social psychologist, Pennebaker was concerned about the implications of asking people to share their secrets with another person. So, he asked them to write about it.

Boost Your Entire Body: What Writing Secrets Can Do

Pennebaker ran his seminal study using expressive writing in 1986. Over four days, participants wrote continuously for 15 minutes each day. The control group was instructed to write objectively about superficial topics. Meanwhile, participants in the experimental group were asked to write about the most traumatic experiences of their lives. Pennebaker’s instructions ran something like this:

For the next four days, I would like you to write your very deepest thoughts and feelings about the most traumatic experience of your entire life, or an extremely important emotional issue. You might tie your topic to other parts of your life: your childhood, your relationships with others, your past, present or future. All of your writing is confidential. Don’t worry about spelling, grammar or sentence structure. The only rule is that once you begin writing, you continue until the time is up.


Pennebaker remarks that participants were stunned by these instructions. “Previously, virtually no one had ever encouraged them to write about some of the most significant experiences of their lives. Many students came out of their writing rooms in tears,” he writes, “but they kept coming back. And, by the last day of the experiment, most reported that the experience had been profoundly important for them.”

Following the experiment, Pennebaker tracked several measurements. His most striking finding was that relative to the control group, the experimental group made significantly fewer visits to the doctor in the following months. Pennebaker’s results prompted hundreds of follow-up studies by his team and others. They found evidence that people who practiced expressive writing experienced many benefits, including:

  • Decreased anxiety, blood pressure, depression, muscle tension, pain and stress
  • Enhanced lung and immune function
  • Improved memory, sleep quality and social life
  • Increased grades and work performance

Initially, Pennebaker attributed the benefits of expressive writing to a cathartic effect. People confronted past traumatic events by expressing their difficult feelings – therefore, they felt better. He became fascinated, however, with further questions: What is it about writing that makes a difference? Why do some people get better while others don’t? Can we identify healthy writing?

Recognizing Healthy Writing: How Junk Words Help People Heal

Pennebaker’s questions led him to study the ways people use language. After developing his own text analysis program, he began analyzing writing samples to predict which participants would show health improvements.

To Pennebaker’s surprise, the key differences were not found in the use of content words (happy, crying, idea, badly), but rather how people used “junk” or function words (I, the, and, to, a). Using hundreds of thousands of writing samples, Pennebaker made a surprising discovery about the role of language in coping with trauma.

For example, people who moved in a positive direction wrote about their situation from multiple perspectives. They began with “I”-focused language to describe their own viewpoint. In later sessions, these individuals used “he/she/they”-oriented language before shifting back to “I.” According to Pennebaker, this cycle represents the helpful ability to consider different viewpoints – and a key factor in helping people process their most difficult experiences.

People who improved also used more cognitive words – like “realize,” “think,” “consider,” “because” and “reason.” These words helped the writer construct a coherent story, experience insights and find a path forward. Across a range of language samples, from expressive writing to speed dating, Pennebaker and his students proved their analysis could predict with startling accuracy which relationships would last, who was telling the truth and which people were coping well with painful experiences.


Five Ways to Bring Expressive Writing to Your Clients

How might your clients benefit from the healing power of writing? There are several ways you can take advantage of Pennebaker’s research and help clients reap the rewards:

1. Is a secret stressing them out? Encourage clients to write it down.

Part of the magic of Pennebaker’s approach is that participants wrote to and for themselves. They never received feedback on their writing. The most significant benefits were often experienced by those who wrote about previously undisclosed events.

Clients may eventually be willing to talk about deeply personal experiences, but Pennebaker notes some individuals get to the heart of their issues more quickly without an audience. The option to keep their writing private can help ease challenges of building trust.

To try this approach, invite clients to write about a topic they have been avoiding – or any subject that strongly influences their thoughts and feelings. Although many people in Pennebaker’s studies reported feeling sad after writing about difficult experiences, this effect was short-lived and overshadowed by the benefits that followed.

If clients would like to share what they wrote about, encourage them to talk about it rather than read aloud. Remind them that expressive writing is for their benefit alone. The purpose is to be completely honest with themselves. Some people choose to keep their writing and see how they change over time. Others prefer to destroy it immediately. Encourage clients to choose what works for them.

It’s important to note that writing may not always be a good fit. According to Pennebaker’s research, the best time for people to write about emotional upheaval is when they believe they are thinking about it too much. It is usually not beneficial to push people to write about traumatic experiences immediately afterward. It may also be unhelpful to encourage clients to reawaken past experiences if they have already adapted well. 

2. Do clients need time to get focused and ready? Have them write in the waiting room.

In a therapy session, the first 10 minutes are often needed for clients to catch up and re-establish the relationship. To jump-start appointments, Pennebaker recommends having clients write about their most pressing issues for 10 minutes before their appointments. With this approach, some people are much more focused and ready when sessions begin.

As noted above, clients should be free to keep their writing samples. It is the writing process that is helpful – not the expectation that they read or share what they write.

3. Want to capture ongoing benefits? Suggest clients make a habit of writing in a journal.

If a client finds that writing works well for them, they may want to include journaling in their daily routine. This can allow people to make the most of ongoing benefits, including stress relief, improved memory and a boost to the immune system.

In the first expressive writing studies, participants experienced meaningful results after writing for 15 minutes each day. However, James Pennebaker notes there are a thousand ways to write and experience health benefits.

If writing on paper doesn’t work for a client, let them know personal voice recordings can be equally effective. Encourage them to experiment and find their ideal practice.

4. Are you hearing the same story? Lead clients to shift perspective once in a while.

Some people can get stuck telling the same story forever, Pennebaker notes. He explains these individuals repeat the same language indefinitely and miss the potential benefits of expressive writing.

If your client is stuck in a loop, try prompting them to change perspective through writing. How do they think their situation appears to another person? How would they view this situation during a time in their past or future? What insights have they uncovered as time passes?

It’s important that writing doesn’t turn into another form of rumination, Pennebaker explains. If writing doesn’t seem helpful to your client, it’s best to change things up.

5. Looking for structure? Bring evidence-based expressive writing tools to your practice.

If your clients would benefit from structure and guidance in their writing, you may want to consider an evidence-based curriculum. The Change Companies® publishes Interactive Journals that use expressive writing to guide and motivate individuals toward positive behavior change.

Interactive Journaling® is a structured process that helps people reflect on where they’ve been, where they are, and where they wish to go. Interactive Journals are compatible with the ASAM dimensions and have underpinnings in expressive writing, motivational interviewing, cognitive-behavioral therapy, and the transtheoretical model of behavior change. 

Atlas is a digital platform that merges the evidence-based practices of Interactive Journaling® with technology to improve how justice and treatment organizations deliver and measure individualized programming. Atlas is mobile-first and tablet-friendly, which helps organizations serve more clients across the continuum of care, including those who would benefit most from telehealth and virtual programming.