Violence perpetrated by members of one’s own ethnic group produces up to five times more trauma than violence from opposing groups. Joan Barceló and Keshana Ratnasingham examined mental health outcomes among Tamil civilians in postwar Sri Lanka by comparing exposure to violence perpetrated by ethnic outgroups versus violence perpetrated by coethnics. The authors surveyed 628 Tamil adults in the Jaffna district in 2022, thirteen years after the end of Sri Lanka’s civil war. Respondents reported exposure to violence from Sinhalese forces and from Tamil actors, primarily the Liberation Tigers of Tamil Eelam. Using validated clinical instruments, the authors measured post-traumatic stress disorder (PTSD) and post-traumatic growth, which refers to positive post-trauma changes such as greater appreciation for life or strengthened personal resilience. Results showed that intragroup violence, which can erode trust within one’s community, disrupts support networks, and create a feeling of betrayal, increased PTSD scores nearly four times more than intergroup violence. The authors found that intragroup violence inflicts three to five times more trauma than intergroup violence. Additionally, intergroup violence was positively associated with post-traumatic growth, while intragroup violence showed no such effect. The study found that 43.3% of respondents experienced probable PTSD and 38.2% showed moderate-to-high post-traumatic growth. According to the authors, these findings highlight the need to consider the source of violence when designing post-conflict mental health interventions, with intragroup violence cases requiring particular focus on community reintegration and trust restoration.
PNAS Nexus
Mental health impact of intragroup vs. intergroup wartime violence
31-Mar-2026