To effectively address support for intergroup violence, we must understand the psychology promoting it. Dehumanization—the explicit and blatant denial of an outgroup’s humanity—is widely considered one such promoter, which has informed extensive research and practice on support for intergroup violence. Nonetheless, dehumanization is often intertwined with intense dislike, raising concerns that dehumanization’s explanatory power is much more restricted than widely assumed. In the extreme, “dehumanization” is merely another way to express dislike. If so, then theories of dehumanization distort our understanding of the psychology promoting support for intergroup violence. Here, we test dehumanization’s reality and explanatory power through three studies that span diverse methods and samples. First, we meta-analyze existing studies on dehumanization and dislike to establish their independent effects on support for violence (k = 120; N = 128,022). We then test the generalizability of these effects across four violent conflicts in the United States, Russia and Ukraine, Israel and the Palestinian diaspora, and India (NTotal = 3,773). In these studies, we also test whether individuals’ dehumanizing responses are merely metaphor or whether they are intended literally. Finally, we experimentally isolate dehumanization’s role in support for violence in another U.S. sample (N = 753). Our results converge to demonstrate that dehumanization (a) is distinct from dislike and often literal, (b) has a unique—and particularly strong—relationship with support for violence, and (c) can promote such support. This clarifies our understanding of the psychology promoting support for intergroup violence and can inform efforts to address it.