Our time is marked by a resurgence of hate that threatens to increase oppression. Social media has contributed to this by acting as a medium through which hate speech is spread. How should we model the spread of hate? This article considers two models. First, I consider a simple contagion model. In this model, hate spreads like a virus through a social network. This model, however, fails to capture the fact that people do not acquire hatred from a single infectious (...) contact. Instead, it builds up in a person's beliefs and attitudes through time until the infection reaches a level where the subject themselves becomes a generator of hate speech. Second, to accommodate this, I consider an alternative model known as complex contagion. I argue that not only is a complex contagion model more explanatory and predictive, but it can be used to explain why certain features of social media cause it to be a promoter of hate. I conclude by sketching some mitigation strategies. (shrink)