This study introduces a methodology to decompose total discrimination (TD) into statistical discrimination (SD) and preference-based discrimination (PbD). For this purpose, we use a public goods game with victims, non-victims, and ex-combatants of the Colombian conflict as a case study. The research aims to explore how beliefs and preferences shape discriminatory behaviors among these groups. The methodology involves unconditional and conditional cooperation decisions to isolate implicit beliefs and preferences. Based on these decisions, expected contributions from partners are estimated, and the components of discrimination are disentangled. Findings reveal that PbD predominates as the main form of intergroup discrimination. Victims exhibit lower discrimination toward non-victims compared to the discrimination non-victims show toward victims. Moreover, implicit beliefs alone do not fully explain the observed behaviors, highlighting the role of contextual factors and preferences. This approach offers an innovative tool for analyzing intergroup dynamics in various settings.