Before revision:  However, scholars do not often account for interactions between beliefs in their models of social contagion . Instead, they assume that beliefs spread independently of one another .
After revision:  However, scholars do not often account for interactions between beliefs in their models of social contagion have almost exclusively made the same implicit assumption: that only one belief, idea, or practice spreads through the population at a time. It is a default assumption that we don't bother to state, let alone justify. The assumption is so ingrained that our literature doesn't even have a word for "whatever is to be diffused", because we have never needed to discuss more than one of them. But this assumption is obviously false. Millions of beliefs, ideas, and practices (let's call them "diffusants") spread through social media every day. To assume that diffusants spread one at a time (or more generously, that they spread independently of one another .