Despite countless international efforts for the peaceful resolution of armed conflicts, why are so many conflicts still observed today? To find an answer to this question, the author seeks to test the following hypothesis; it is difficult to find the root causes of armed conflicts because peace and conflict studies have not paid much attention to research on human emotions. By reviewing previous studies, this hypothesis has been proven true for the following reasons. Firstly, the so-called “rational model” in conflict studies (including the areas of International Law, International Relations and International Politics) does not reflect peoples' felt emotions such as hatred and fear. Secondly, the present international system is not designed to handle politically motivated, aggressive emotions properly. As a conclusion, this essay notes that a pro-social emotion such as empathy does not necessarily prevent conflicts. Interdisciplinary research efforts concerning armed conflicts are needed so that the “vulnerable human model” which indicates a person who can easily switch from victim to aggressor or vice versa will replace the “rational model” in the future research.