This paper investigates the origins of sortal numeral classifiers in the Indo-Iranian languages. While these are often assumed to result from contact with non-Indo-European languages, an alternative possibility is that classifiers developed as a response to the rise of optional plural marking. This alternative is in line with the so-called Greenberg-Sanches-Slobin (henceforth GSS) generalization. The GSS generalization holds that the presence of sortal numeral classifiers across languages is negatively correlated with obligatory plural marking on nouns. We assess the extent to which Indo-Iranian classifier development is influenced by loosening of restrictions on plural marking using a sample of 65 languages and a Bayesian phylogenetic model, inferring posterior distributions over evolutionary transition rates between typological states and using these rates to reconstruct the history of classifiers and number marking throughout Indo-Iranian, constrained by historically attested states. We find broad support for a diachronically oriented construal of the GSS generalization, but find no evidence for a strong bias against the synchronic co-occurrence of classifiers and obligatory plural marking. Inspection of the most likely diachronic trajectories in individual lineages in the tree shows a stronger effect of the GSS among Iranian languages than Indo-Aryan languages. Taken as a whole, these findings suggest that the association of classifiers and optional number marking in Indo-Iranian is neither solely the effect of universal mechanisms nor of the contingency of local contact histories.

本文研究了印度-伊朗语言中排序数字分类词的起源。虽然这些通常被认为是与非印欧语言接触的结果，但另一种可能性是分类器是作为对可选复数标记兴起的回应而发展起来的。这种替代方法符合所谓的 Greenberg-Sanches-Slobin（以下称为GSS）泛化。社会保障部概括认为，跨语言的排序数字分类器的存在与名词上的强制性复数标记呈负相关。我们使用 65 种语言的样本和贝叶斯系统发育模型评估了印度-伊朗分类器发展受到放松对复数标记限制的影响的程度，推断类型学状态之间进化过渡率的后验分布，并使用这些速率来重建历史整个印度 - 伊朗语的分类器和数字标记，受历史证明的国家的限制。我们发现对GSS历时导向的解释得到广泛支持概括，但没有证据表明对分类词和强制性复数标记的同步共现存在强烈偏见。检查树中各个谱系中最可能的历时轨迹表明，GSS在伊朗语言中的影响比印度-雅利安语言更强。总的来说，这些发现表明，印度-伊朗语中分类词和可选数字标记的关联不仅是普遍机制的影响，也不是当地接触历史的偶然性。