Stoic regulation: The influence of military combat training on neurobehavioral indices of anger

Military combat training, where stoic-like pedagogy promotes anger regulation, offers a paradigmatic case study for examining response to angering provocations and internalization of regulatory strategies. To this end, we conducted a prospective neuroimaging study prior to and towards the end of intensive infantry training of combat soldiers recruited to the Paratroopers Brigade of the Israel Defense Forces. A control group was recruited consisting of age matched volunteers who took part in one-year pre-army civil service programs. At each time-point, participants played a modified Ultimatum Game (UG) to which anger was further infused using interpersonal insults, while their brains were scanned using functional Magnetic Resonance Imaging. We previously showed that within the 60 participants of the first time-point (38 soldiers and 22 civilians) there were no differences in any of the anger measures including behavior, emotional reports and brain activations between soldiers and civilians. Specifically, we showed that all participants in the first time-point were mostly angry and rejected more offers as those offers became more unequal. Additionally, it was found that participants who gained more money reported less anger and more positive feelings, and had more ventromedial Prefrontal Cortex (vmPFC) and less Locus Coeruleus (LC) activation, while the reverse pattern was found for those participants who gained less money. Congruent with previous findings associating the vmPFC with implicit emotion regulation and the LC with arousal and aggression, we asserted that these two neurobehavioral response patterns reflected a regulated and an unbalanced profile of anger, respectively. Here we examined the results of the second timepoint (29 soldiers and 17 civilians), which demonstrated that soldiers with a priori unbalanced anger profile displayed an increase in monetary gain, an increase in reported positive emotions, and an increase in vmPFC activation in response to the anger-infused UG at the end of combat training, thus presenting a regulated anger profile. Soldiers with a priori regulated profile displayed a marginal decrease in monetary gain and an increase in anger, but generally showed no differences compared to their angry colleagues from the first time-point. The civilians control group displayed no changes in any of the anger related measures between timepoints. Findings support the formulation of Stoic pedagogy in military practice as a program that empowers anger regulation and suggest that an intense socio-cultural practice such as combat training styles one's mind and body in a fashion that decreases individual variability and produces uniform and regulated responses to anger.