Variation in language use is different from variation in genes Some comments on Haider’s model of grammar change Andrea Sansò Università dell’Insubria andrea.sanso@uninsubria.it Abstract This commentary discusses some aspects of Haider’s model of grammar change that are problematic from the perspective of usage-based approaches to language change. These aspects include (i) the postulated equivalence between intentionality and teleology, (ii) the metaphorical nature of Darwinism when applied to other domains, and (iii) the nature of explanations of language change. With respect to (i), it is argued that equating intentionality with teleology disregards the fact that innovation in grammar is not unprincipled like in genes. With respect to (ii), the question is whether a comparison between as different concepts as human behaviors/brains and genes/populations can be considered as more than a metaphor (however powerful). Finally, with respect to (iii), a number of diachronic-typological studies are discussed that concur to suggest that variation in speakers’ verbal productions is largely adaptive, and therefore selection operates on a skewed pool of variants in which non-adaptive/dysfunctional variants are a minority (if any). Keywords: intentionality, teleology, usage-based models, diachronic typology. 1. Introduction Haider’s position paper claims that grammar change is a phenomenon subject to Darwinian evolution, which can be accounted for by applying the conceptual infrastructure of the Darwinian model to its specificities. Haider classifies instances of language change as (i) determined by social factors, (ii) determined by the interaction between Darwinian selection and social factors, (iii) determined by Darwinian selection only, and (iv) not determined by either social or Darwinian factors (the latter including the dynamics of language contact as well as the random emergence of variants in segregated communities). This commentary is meant to discuss some aspects of Haider’s model that appear to be problematic from the point of view of functional and typological (and, more generally, usage-based) approaches to language change. In Section 2, I will tackle a general problem connected with the pars destruens of Haider’s proposal, namely the postulated equivalence between intentionality and teleology. Section 3 deals with the metaphorical nature of Darwinism when applied to language change, which appears to characterize Haider’s approach on a par with other evolutionary approaches. Some inconsistencies of Haider’s metaphorical mapping are also discussed. Finally, in Section 4, Haider’s position regarding typological explanations of language universals and cross-linguistic tendencies is discussed in the light of recent developments of linguistic typology.