Human syntactic structures are usually represented as graphs. Much research has focused on the mapping between such graphs and linguistic sequences, but less attention has been paid to the shapes of the graphs themselves: their topologies. This study investigates how the topologies of syntactic graphs reveal traces of the processes that led to their emergence. I report a new universal regularity in syntactic structures: Their topology is communicatively efficient above chance. The pattern holds, without exception, for all 124 languages studied, across linguistic families and modalities (spoken, written, and signed). This pattern can arise from a process optimizing for communicative efficiency or, alternatively, by construction, as a by-effect of a sublinear preferential attachment process reflecting language production mechanisms known from psycholinguistics. This dual explanation shows how communicative efficiency, per se, does not require optimization. Among the two options, efficiency without optimization offers the better explanation for the new pattern.

翻译：人类合成结构通常以图示形式出现。 大量研究侧重于绘制这些图表和语言序列之间的图象,但较少注意图表本身的形状:其地形。 本研究调查合成图的地形如何揭示导致其出现的过程的痕迹。 我报告在合成结构中出现了一种新的普遍规律性:它们的地形比机会高得多,其形态无一例外地保持了所研究的所有124种语言(口语、书面和签名)的特征。 这种模式可能产生于优化通信效率的过程,或者通过建筑,作为反映从精神语言学中知道的语言制作机制的亚线性优惠附加程序的一个副作用。这一双重解释表明,通信效率本身如何不需要优化。 在两种备选方案中,效率不优化就能为新的模式提供更好的解释。