Some concepts are more essential for human communication than others. In this paper, we investigate whether the concept of agent-backgrounding is sufficiently important for communication that linguistic structures for encoding this concept are present in young sign languages. Agent-backgrounding constructions serve to reduce the prominence of the agent – the English passive sentence a book was knocked over is an example. Although these constructions are widely attested cross-linguistically, there is little prior research on the emergence of such devices in new languages. Here we studied how agent-backgrounding constructions emerge in Nicaraguan Sign Language (NSL) and adult homesign systems. We found that NSL signers have innovated both lexical and morphological devices for expressing agent-backgrounding, indicating that conveying a flexible perspective on events has deep communicative value. At the same time, agent-backgrounding devices did not emerge at the same time as agentive devices. This result suggests that agent-backgrounding does not have the same core cognitive status as agency. The emergence of agent-backgrounding morphology appears to depend on receiving a linguistic system as input in which linguistic devices for expressing agency are already well-established.

有些概念对人际交流比其他概念更重要。在本文中，我们调查了代理背景的概念对于交流是否足够重要，以至于在年轻的手语中存在用于编码该概念的语言结构。代理人背景构造可减少代理人的声望–一本书被推翻的英语被动句是一个例子。尽管这些结构在跨语言方面得到了广泛的证明，但是关于这种设备以新语言出现的先验研究很少。在这里，我们研究了在尼加拉瓜手语（NSL）和成人家庭签名系统中如何出现代理人背景构造。我们发现NSL签名者已经创新了用于表达代理背景的词汇和词法设备，这表明传达事件的灵活观点具有深厚的交流价值。同时，代理后台设备没有与代理设备同时出现。该结果表明，代理人背景与代理人没有相同的核心认知状态。