**6. Conclusions**

Results from this study support the three stages of evolution from the use of uninflected verbs towards the emergence of a more grammatical use of space with single agreemen<sup>t</sup> and then double agreemen<sup>t</sup> verbs. However, the striking element in the present study is the early appearance of agreemen<sup>t</sup> in space in YMSL as compared to other emerging sign languages that have been documented to date. The proposed explanation is that the use of a geocentric Frame of Reference and the habits of Yucatec Maya speakers to use the gesturing space symbolically is what steers deaf signers towards a more arbitrary use of the signing space. Deaf YMSL signers from the first generation also habitually locate entities in the space around their body respecting real-world orientation. The hypothesis is that they rely on this habit and extend it to the creation of R-loci and verb agreemen<sup>t</sup> constructions in the signing space. As pointed out by Meier (2002) and Senghas et al. (2005), second and subsequent generations of signers usually improve on and systematize the language, and this is clearly what second generation YMSL deaf signers are doing in employing double agreemen<sup>t</sup> constructions systematically in the task. While this explanation holds for the early emergence of agreemen<sup>t</sup> in YMSL, it might not directly apply to ABSL or Kata Kolok, for instance, and each group follows its own specific pace, with various local constraints on the language.

Documenting and taking into account the surrounding culture proves fundamental to understand emerging sign languages' linguistic structures, although it is too often overlooked. The YMSL data shed light on an issue sometimes ignored, that is, the potential richness of first generation signers and homesign systems, as well as the importance of the cultural setting and gestural habits of the surrounding culture in which a new sign language emerges.

**Funding:** Part of this research was supported by the MPI-Language and Cognition Group and the CONACyT project FC-2016-2893.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** I wish to sincerely thank the people of Chicán, Nohkop and Trascorral for their patience and will to share their language and culture with me. I would also like to thank Josefina Safar who helped with a first version of this study, Lorena Pool Balam for helping with some of the data collection, and the participants of the 2012 EuroBABEL workshop. I am indebted to the anonymous reviewers and Wendy Sandler for their useful comments and relevant critics as well as Carolyn O'Meara for her generous assistance with the manuscript.

**Conflicts of Interest:** The author declares no conflict of interest.
