Event Centrality, Perceived Injustice, and Their Shared Influence on Posttraumatic Stress: A Commonality Analysis
Alicia Fulton, Rebekah Marcengill, Gretchen Wanning, Seren Krishingner
In recent years, cognitive appraisals have emerged as an important category of predictors of posttraumatic stress severity (PTSS). Two such cognitive appraisal variables are event centrality and perceived injustice. Event centrality, first named and measured by Berntsen and Rubin in 2006, has since grown in interest to trauma researchers (e.g., see Gehrt et al., 2018, for a systematic review). Event centrality encompasses a pattern of trauma appraisals in which the individual construes the event as central to their identity and life story, as a turning point in the life story, and as a reference point for appraisals of other life events and experiences. Much like event centrality, perceived injustice is a strong predictor of PTSS (e.g., Agtarap, Scott, Warren, & Trost, 2016), but studies examining perceived injustice have come from a different research sector—research on physical injury and pain (e.g., Sullivan et al., 2009). Perceived injustice encompasses a pattern of trauma appraisals in which, as part of one’s injury or trauma experience, the individual has been unfairly wronged or a social contract has been violated, and there is a strong sense of loss relating to the event/injury. Though both variables show consistently strong relationships with PTSS, we are not aware of any studies that have examined both factors together. We examined these two variables together as predictors of PTSS to examine their unique and common contributions to PTSS. Additionally, we conducted an underutilized analysis that serves this exact purpose: commonality analysis. Commonality analysis is a procedure for breaking down R2 in multiple regression analyses into the percent of variance in the dependent variable associated with each independent variable uniquely, and the proportion of explained variance associated with the common effects of predictors (e.g, Nimon, 2010). We hypothesized that each of the predictors would explain some PTSS variance uniquely and that they would share some common variance, but because no previous studies have examined these relationships we did not make specific predictions about relative amounts of PTSS variance explained. This project is a secondary data analysis of a larger project conducted by the first author. Participants were 472 U.S.-based Amazon Mechanical Turk workers (66% women; Mage = 36.71, SDage = 12.90) who reported their trauma history, identified their worst event, and completed several self-report measures in relation to that worst event. Together, the two predictors explained approximately 42% of the variance in PTSS, R-squared = .425. Of the variance accounted for in PTSS, event centrality uniquely accounted for 4.15%, and perceived injustice uniquely accounted for 32.86%. The common effect of the two predictors on PTSS was stronger; 62.99% of the explained variance in PTSS was common to both event centrality and perceived injustice.
Alicia Fulton is a senior psychology major from Kingstree, SC, a small town outside of Charleston, SC. Alicia is a lead student author in the Stress and Cognition lab, led by Dr. Southard-Dobbs studying post – traumatic cognitions and presented at the Southeastern Psychological Association (SEPA) Conference. Outside of class, Alicia spends her time serving our country in the SC National Guard, volunteering at Beyond Abuse in the Greenwood area and exploring her surroundings as much as possible.
Rebekah Marcengill is a junior psychology major and art minor from Greenwood, S.C. She is a research assistant in the Stress and Cognition lab led by Dr. Southard-Dobbs. She is also a supplemental instructor for Psychology 101.
Gretchen Wanning is a senior from Greenwood majoring in psychology. She is a research assistant in Dr. Southard-Dobbs’s Stress and Cognition Lab, and her love for psychology has grown because of the interesting and detailed topics the lab has researched over the last two semesters. After she graduates, Gretchen plans to attend an accelerated nursing program.
Seren Krishingner is majoring in psychology and sociology at Lander University. Seren is studying how post-cognitive and social factors influence post-traumatic symptom severity in The Stress and Cognition Lab, led by Dr. Southard-Dobbs. Seren’s major achievements include co-authoring two award-nominated research projects and presenting them at the Southeastern Psychological Association’s 68Th Annual Meeting, being inducted as a lifetime member of The International Sociology Honor Society (AKD), and volunteering for Beyond Abuse.