When combat prevents PTSD symptoms—results from a survey with former child soldiers in Northern Uganda

It is estimated that at any one time, 300.000 children under the age of 18 are used as soldiers in warfare [1]. Technological advantages like the development of lightweight automatic weapons have resulted in an increase of child soldiers in armed conflicts [2]. From the mid-90’s to 2006 the Lord Resistance Army (LRA) has been fighting in Northern Uganda and is responsible for the mutilation and mass execution of civilians and the abduction and recruitment of children as soldiers in the armed rebel force [3]. Since the LRA relocated its residence to southern Sudan and the Democratic Republic of Congo, several studies have investigated the impact of the war in Northern Uganda and reported devastating effects on the mental health of former child soldiers, especially because of the development of trauma-related symptoms [4‐7]. Several studies reported a clear dose-effect relationship between the exposure to different stressful life events and the risk of development of post traumatic stress disorder (PTSD) in various especially war-affected populations [8‐11]). Thus, the cumulative exposure to life-threatening events increases the risk of development of PTSD over time. The concept of perpetration-induced traumatic stress (PITS) was introduced to describe an observable phenomenon that former perpetrators show a higher degree of PTSD [12‐14]. However, homicide may have evolved as a profitable strategy in man, leading to greater reproductive success and a greater evolutionary benefit of those who perpetrate aggressive acts [15, 16]. But such an evolutionary advantage of violent behavior would be eliminated if the exposure to violence cues that are related to their offensive behavior traumatized the perpetrator.

We argue that perpetrating violent acts could actually help to ‘immunize’ a person against adverse effects of traumatic stressors and significantly reduce the risk of developing PTSD [17]. During the course of evolution, not only the purposeful hunting of animals but potentially also of humans may mediate powerful social and psychological rewards and hence interact with the vulnerability of psychological disorders [17]. Most of the research on interspecies aggression stems from primates and has proven that the elimination of neighboring tribes facilitates food supply as well as reproduction and is beneficial for the adults health [18]. Similarly, in-group co-operation and out-group enmity is beneficial for the fitness of the own group in humans [19]. In research on aggression, this instrumental use of aggression for these secondary rewards have been extensively studied. Instrumental aggression has been linked to the secondary rewards, like the gain of social status [20, 21], wealth [22], or reproductive success [23]. However, the mutilation of the victims has not been defined as a primary goal of instrumental aggression yet [24, 25]. Nell [26] proposed an innate and strongly male-gendered human blood lust that is either expressed by phenomena like bystanders or game hunting in peaceful regions or culminates in the purposeful mutilation of victims in war-affected regions. However, the rewarding effects of cruelty have received only little attention in aggression research. We therefore started to investigate appetitive aggression, i.e. the perpetration of violence and/or the infliction of harm to a victim for the purpose of experiencing violence-related enjoyment, empirically. Recently, we showed in a path-analytic model involving Rwandan prison inmates who were all accused for crimes related to the 1994 genocide that a higher appetitive aggression was associated with a reduced risk to develop trauma-related symptoms [17]. To validate this finding and gain further insight into the underlying pathways that contribute to potential trauma-related illness in perpetrators, we surveyed male former child soldiers that have joined the Ugandan LRA. As we expect a higher degree of attraction to violence in men [26‐28] this study focused on male participants. We hypothesized that high levels of appetitive aggression could promote resilience from trauma-related symptoms. The victim’s struggling, their blood and vocalization were defined as the essential rewarding cues for the perpetrator. To control for the impact of socialization the time spend in the bush was added as a covariate to the analyses. Moreover, we supposed that the personally committed delinquency would predict the extend of appetitive aggression.

In this study, we examined the relationship between appetitive aggression assessed with the AAS and trauma-related symptoms in a sample of formerly abducted child soldiers in Northern Uganda and a non-abducted control group. The Appetitive Aggression Scale [37] assesses the extend of appetitive experience with the perpetration of violence or the infliction of harm that is aimed to experience violence-related enjoyment by the exposure to violence cues such as the struggling of the victim. Appetitive aggression was present at least to some degree in both the abducted and the non-abducted group, except that the extent was more substantial in the formerly abducted group. We identified the number of personally committed crimes to be the best and only significant predictor of AAS sum score in both groups, without significant differences in this relationship between the two groups. This relationship is well explained by assumptions of a cycle of violence: abused children become murderers and perpetrators of other crimes of violence [45, 46]. The present results indicate “that violence breeds violence” not simply in the form of reactive aggressive acts but fosters appetitive aggression, which in turn increases the likelihood of violent offenses. Participants in the formerly abducted group experienced more trauma-related symptoms than participants in the non-abducted group which would be expected, given their much greater traumatic stress. However, PTSD related symptoms were reduced or even absent in those who reported violent acts as more positive. The resilience against mental illness in those who report a high propensity towards violence has also been found for perpetrators of the Rwandan genocide [17]. However, there is no ultimate resilience because the protection wanes as the exposure to traumatic stressors exceeds a certain threshold.

Studies on Vietnam Veterans have reported a high degree of PTSD in former soldiers [47]. Even professional torturers reported trauma-associated symptoms and Milgram reported that participants in his study on obedience reported distress when they applied electroshocks [48, 49]. Proponents of the PITS-concept suggest that “the human mind… is not well set up for killing” and use the results cited before for their line of argument [12]. We also found a higher PTSD symptom severity in those who perpetrated violence compared to those who were not involved in armed conflicts. However, the conclusion that can be drawn from this result takes on a different connotation when one considers the underlying mechanisms leading to traumatization. Baumeister and Campbell [50] emphasize that “to understand the psychology of perpetrators, it may be necessary to distance oneself from the victim’s view”, as the perception of violence differs remarkably between the perpetrator’s and victim’s perspective [51]. The same seems to be true for the mechanisms leading to the development of trauma-related symptoms. Moreover, to understand why some perpetrators are traumatized while others engage in killings without remarkable distress caused by their own atrocities, we propose that a differentiated view of the perception of cruelty could be crucial. The appeal of violence does not seem to override the strong mechanism of the increasing risk for trauma-related mental illness with a cumulative exposure to threats to one’s life [8, 10]. However, it can lead to a substantial risk-reduction. Moreover, it has to be emphasized that only the self-experienced but not the witnessed traumatic event types lead to trauma-related symptoms. Thus, as was indicated by army screening attempts in World War II to sort out those who are vulnerable for “stress disorders”, perpetrators differ in their relative risk of being traumatized [52]. In addition, we would not expect perpetrators to be more affected by the exposure to life-threatening situations in a qualitative manner as suggested by the PITS concept but rather the frequency of the exposure to different life-threatening situations has to be taken into account to draw inference about traumatization in perpetrators. Given the correlational nature of the cross-sectional study, the observed relationship between aggression and traumatic stressors could be also explained by the assumption that those who experience aggression to be more appetitive engage more frequently in severe atrocities. Thus, the likelihood for the exposure to life-threatening situations increases. This explanation is in line with studies that repeatedly demonstrated that the engagement in violence also increases the risk of personal victimization [53‐55]. A second explanation can be traced back to the sample characteristics. It has to be emphasized that two types of participants are missing in this sample: Participants with a high number of self-experienced event types and low AAS scores and participants with high AAS scores and a low number of self-experienced event types. We assume that the former ones suffer from more severe PTSD symptoms in line with the model and the risk for PTSD associated mortality would be high too [56, 57]. Thus, either this subgroup could not be obtained in a convenient community sample or it became a victim of fatal casualties. Contrary, PTSD symptoms should not be present in the latter ones. We therefore assume that they might still be engaged in fightings of the LRA.

The present results confirm a model that suggests that in an environment dominated by organized violence, exposure to traumatic stressors increases appetitive aggression and furthers violent behavior, thus driving a cycle of violence. The increasing appetitive aggression on the other hand seems to relate to a smaller vulnerability for trauma-related mental illness, although there seems to be no ultimate resilience. Therefore, we predict that mental illness will be a likely consequence for those entrapped in the cycle of violence. Future studies have to show if this result can be generalized to other measures of trauma-spectrum disorders.