In a very interesting preliminary study, researchers, Jill M. Hooley and Sarah A. St. Germain (Department of Psychology, Harvard University) explored the question, does changing beliefs about the self change pain endurance in people who self-injure (Hooley & St. Germain, 2014)? In a nutshell, the results of this study suggested the answer can be yes.

Study Overview

• Pain endurance was defined as “the amount of time participants exposed themselves to the painful stimulus after reporting onset of pain” (p. 300).
• The study design had a control group (no history of self-injury or current Axis I psychological disorder) and a non-suicidal self-injury group.
• The procedure involved participants taking part in a 2-hour lab experiment session. First, participants completed a pain threshold and pain endurance measure. Next, they were randomly assigned to one of three 5-minute experimental manipulation groups (positive mood via listening to uplifting music, positive self-worth via an exercise exploring participants’ positive traits, or neutral via reading a written passage about Ecuador). After this, participants completed the pain threshold and endurance test again. *Some participants, though not all, also completed measures before and after the experimental manipulation asking people to report how positive their mood was at the moment and how positively they were feeling about themselves in the moment.
• Sample size was relatively small (134 individuals total), which the researchers noted was a potential limitation of the study.

Results in this study were that

1. Those in the positive self-worth manipulation (regardless of history of self-injury) reported greater increases in positive feelings about themselves than those in both the positive mood and neutral experimental manipulation groups).
2. Overall, participants reported being in a more positive mood after the experimental manipulation regardless of which manipulation they were in.
3. After the cognitive intervention in the positive self-worth manipulation (where participants reported feeling better about themselves after the manipulation) “the amount of time that participants were willing to endure physical pain decreased by 69.06 s [seconds] (SD = 107.24). This difference represents a 49.8% decrease in pain endurance for NSSI [non-suicidal self-injury] participants relative to their baseline pain-endurance scores. Control participants who received the same intervention showed a 9.13 s [second] (SD = 61.53) or a 10.4% decrease in pain endurance between their first and second assessments” (p. 301). The difference between how much pain endurance decreased between the control group and the NSSI group  was statistically significant.
4. There were statistically significant differences in pain endurance between the control group (no history of self-injury) and the self-injury group prior to the experimental manipulation. Specifically, the self-injury group had higher pain endurances. Interestingly, after participating in the positive self-worth manipulation, there was no longer significant differences in pain endurance between the self-injury and control group. “…The cognitive intervention [positive self-worth manipulation] seemed to normalize previously elevated pain endurance in the NSSI group” (p. 301).
5. An increase in positive feelings about oneself as associated with a decrease in pain endurance for those with a history of self-injury but not for those in the control group (those without a history of self-injury) who showed no significant change in endurance after the positive self-worth manipulation.

So what might all of this mean for understanding self-injury? What might this mean when applied to working with people who self-injure? If you have access to the journal article (e.g., via an academic library), you can read the article for some of the authors’ interesting and valuable ideas (the title of the article provides some clues). You can also learn about related research and relevant implications in the practically focused ebook, Working with people who self-injure: A resource guide for helping professionals.

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Reference

Hooley, J. M., & St. Germain, S. A. (2014). Nonsuicidal self-injury, pain, and self-criticism: Does changing self-worth change pain endurance in people who engage in non-suicidal self-injury? Clinical Psychological Science, 2, 297-305.