To develop a nuanced account for selection within an epidemiological, population-based model of language contact and change, it is useful to consider possible conduits and filters on linguistic transmission and distribution. Richerson & Boyd (2005) describe a number of candidate biases in their evolutionary analysis of culture as a biological phenomenon (cf. Cavalli-Sforza & Feldman 1981, Sperber 1985, 1999, Boyd & Richerson 2005). This paper explores some of these biases with reference to language, exploring a set of analytic distinctions for a proper understanding of population-level linguistic processes. In putting forward these ideas, this paper echoes recent attempts to combine linguistic and biological concepts in the analysis of language diversity and change.