Beliefs serve at least two broad functions. First, they help us navigate the world. Second, they serve as signals to manipulate others. Philosophers and psychologists have focused on the first function while largely overlooking the second. This article advances a conception of signals and makes a prima facie case for a social signaling function for at least some beliefs. Truth and rational support are often irrelevant to the signaling function. If some beliefs evolved for a signaling function, then we should (...) expect various biases that aid in the manipulation of others. (shrink)