What personality traits moderate the effects of trauma on empathy? Logically there are three ways trauma can affect a person's propensity for empathy.


increase
decrease
no change


What are the key personality traits that can be used as predictors of this outcome?
There is a large and diverse literature on this topic which paints a complex picture of the relationship between trauma and empathy. 

Some studies have found significant trauma symptoms to be related to less empathy. A study of Israeli children who had experienced the trauma of Arab missile attacks found that 66% of children with very negative attitudes towards Arabs had severe posttraumatic symptoms, while none of the children who expressed balanced attitudes towards Arabs had severe posttraumatic symptoms (Laor, Wolmer, &amp; Cohen, 2004). Children with balanced attitudes also exhibited more prosocial behavior, offering to donate 35% more candy to ill peers than children with more negative attitudes. Overall, the authors found that those with very negative attitudes were less able to regulate their behavior, had poorer defense mechanisms, and had more externalizing and PTSD symptoms, while children with balanced attitudes were older and had fewer symptoms and more positive defenses. Thus, while children with better coping styles had both fewer trauma symptoms and were more empathetic/generous, is not possible to determine the direction of these relationships in this study. Also, the coping styles and attitudes of these child could be highly influenced by the environment (i.e., their parents’ behavior and attitudes).

A study of college students found that over 26% reported significant PTSD symptoms and 29-58% various forms of psychological distress following the 9/11 attacks, despite having no personal connection to the event (Woodward, Murrell, &amp; Bettler, 2005). The study also found that a person’s level of empathy was positively correlated with the amount of traumatic stress symptoms they reported; perhaps not surprising, as you might need a certain level of empathy to experience someone else’s trauma so acutely. Additionally, while traumatic stress symptoms were positively correlated with the amount of psychological distress the person was experiencing, empathy was negatively correlated with psychological stress, both directly and via the person’s interpersonal style. That is, those individuals with more empathy and with positive interpersonal styles (a combination of coping skills, attachment, and social support), had better psychological functioning in the face of trauma. 

Other studies have found that trauma may impact empathy in different ways, depending on the type of trauma. One study suggests that trauma which is directed at the self (abuse or severe illness) may not stimulate empathy for the self, resulting in negative psychological  outcomes, but that trauma directed at another (losing a loved one, witnessing injury/abuse of a loved one) may stimulate empathy to help the other person (Keinan, Shrira, &amp; Shmotkin, 2012). Thus, even if the person experiences an event as traumatic, the motivation to help the victim (or others who care about the victim) may result in surges of empathy. 

Another study found that only certain types of empathy were impacted by trauma (Nietisbach, Maercker, Rossler, &amp; Haker, 2010). When these authors compared individuals with PTSD to those without PTSD, they found that both groups had similar levels of the complex empathic skills such as social cognition (i.e., being able to recognize faux pas or take the perspective of others), but individuals with PTSD symptoms were less likely to demonstrate more basic empathic skills such as “empathic contagion,” yawning or laughing when seeing someone else yawn or laugh. The authors also noted that individuals with PTSD for whom more time had passed since their trauma had a greater ability to take the perspective of others compared to individuals with PTSD who were closer to their time of trauma; this may indicate a change in empathic ability over time. Finally, they found that both individuals with PTSD and those without PTSD reported similar self-reported levels of empathy for others, but that those with PTSD reported greater distress when faced with the difficulties of others. The authors hypothesized that individuals with PTSD may be consciously avoiding empathic contagion due to this heightened experience of distress when watching others struggle, meaning part of the empathic deficit may actually be a defense mechanism. 

A study of veterans with PTSD found that those who lacked empathy were more likely to be verbally, but not physically or impulsively, aggressive (Teten, Miller, Bailey, Dunn, &amp; Kent, 2008). However, those veterans who also experienced alexithymia, meaning they are unable to name or describe their emotions with words, were more likely to be impulsively aggressive; a lack of empathy was not significantly associated with impulsive aggression. So, when considering aggressive behavior and trauma, it may be important to recognize that not all negative behavior is necessarily due to trauma’s impact on empathy. 

Other studies have focused on the role of trauma in increasing empathy or helping behavior. One study found that individuals with greater numbers of lifetime traumatic events had greater self-reported empathy and volunteering behavior than those with fewer traumatic events (Frazier et al., 2013). However, this study was unable to conclude whether trauma had led to increases in empathy and whether such an increase was the reason for the increased prosocial behavior. Staub and Vollhardt (2008) have suggested that there are a specific set of experiences that may promote “altruism born of suffering” (i.e., increased empathy in reaction to trauma). Specifically, they propose if individuals who experience a traumatic event then experience psychological healing, social support, positive self-action, and altruistic role models, they may experience a range of post-traumatic growth including increased empathy and prosocial behavior. Staub and Vollhardt (2008) do note as others authors have that empathizing with other people’s distress can cause distress and possibly decrease empathy unless sufficient coping mechanisms are in place. A 2009 paper reviews recent evidence for this concept, and emphasizes the need for a better understanding of the experiences which lead to altruism following trauma, rather than suffering or revenge (Vollhardt, 2009). 

In sum, trauma can impact empathy and prosocial behavior in a variety of ways, depending on individual characteristics and context. The links below should provide you a starting point to find additional resources on this topic. While most of the literature focuses on the impact of trauma on adults with “normal” empathic responses prior to the trauma, Music (2012) provides a theoretical argument that the development and acquisition of empathy may not occur properly when children are subjected to significant abuse or neglect. His paper may be a good reference if you’re interested not only in how trauma impacts existing capacity for empathy, but in how it impacts the development of empathy.

Frazier, P., Greer, C., Gabrielsen, S., Tennen, H., Park, C., &amp; Tomich, P. (2013). The relation between trauma exposure and prosocial behavior. Psychological Trauma: Theory, Research, Practice, and Policy, 5(3), 286-294. DOI: 10.1037/a0027255.  

Keinan, G, Shrira, A., &amp; Shmotkin, D. (2012). The association between cumulative adversity and mental health: considering dose and primary focus of adversity. Quality of Life Research, 21, 1149-1158.  

Laor, N., Wolmer, L., &amp; Cohen, D. J. (2004). Attitudes toward Arabs of Israeli children exposed to missile attacks: The role of personality functions. The Israel Journal of Psychiatry and Related Sciences, 41(1), 23-32.

Music, G. (2012). Selfless genes, altruism, and trauma: Research and clinical implications. British Journal of Psychotherapy, 28(2), 154-171. DOI: 10.1111/j.1752-0118.2012.01276.x

Nietlisbach, G., Maercker, A., Rossler, W., &amp; Haker, H. (2010). Are empathic abilities impaired in posttraumatic stress disorder? Psychological Reports, 106(3), 832-844. DOI: 10.2466/PR0.106.3.832-844

Staub, E., &amp; Vollhardt, J. (2008). Altruism born of suffering: The roots of caring and helping after victimization and other trauma. American Journal of Orthopsychiatry, 78(3), 267-280. DOI: 10.1037/a0014223

Teten, A. L., Miller, L. A., Bailey, S. D., Dunn, N. J., &amp; Kent, T. A. (2008). Empathic deficits and alexithymia in trauma-related impulsive aggression. Behavioral Sciences and the Law, 26, 823-832. DOI: 10.1002/bsl.843

Vollhardt, J. (2009). Altruism born of suffering and prosocial behavior following adverse life events: A review and conceptualization. Social Justice Research, 22, 53-97. DOI: 10.1007/s11211-009-0088-1

Woodward, L. E., Murrell, S. A., &amp; Bettler, R. F. (2005). Empathy and interpersonal style: A mediational model of secondary traumatic stress symptomology following 9/11. Journal of Aggression, Maltreatment, &amp; Trauma, 11(4), 1-28. DOI: 10.1300/J146v11n04_01