**2. Iconicity**

How does communication develop, starting from the invented system of one deaf person used with their hearing communication partners (CPs—a home sign situation), along a continuum to a conventionalized language? The emergence of sign language in a deaf individual in a hearing community is the topic of the article by **Madeline Quam**, **Diane Brentari**, and **Marie Coppola**. The authors focus on handshapes in iconic signs, and study both the signs of homesigning children and homesigning adults, as well as the comprehension of hearing CPs of both groups, and of unrelated hearing and deaf people. The researchers followed Padden et al.'s (2013) work on patterned iconicity in sign languages, which showed different types of iconic motivation underlying either handling or object forms in different sign languages. Quam et al. categorized iconic signs into

those that represent handling an object, those that represent the object itself, and those that represent both (typically, handling with one hand and object with the other). The authors looked for preferences according to category, and for conventionalization across homesigners and their CPs. Among other findings, the authors found that homesigners were more consistent than their CPs; that hearing family members who were exposed at a young age to the deaf homesigning family member understood the home signs better than those who were exposed older; but that American Sign Language signers, who were not CPs of the homesigners at all, understood the home signs best—a tantalizing result.

The article by **Diane Stoianov**, **Diná Souza da Silva**, **Jó Carlos Neves Freitas**, **Anderson Almeida-Silva**, and **Andrew Nevins** examines classifier constructions in Cena, a village sign language in Brazil, and compares them with those of Libras, the established national deaf community sign language. Classifier constructions exist in all known established sign languages. These constructions combine lexically specified handshapes, which classify entities in the world, with the manner of movement and path direction, which are iconic and often considered to be more gesture-like. Stoianov and colleagues address three questions, explaining how each is related to iconicity: (1) whether there is more variation/less conventionalization in the young Cena than in the established Libras, as reported for other sign languages (e.g., Meir and Sandler 2020), and as demonstrated by Mudd et al. in this collection; (2) whether the classifier handshapes are more complex in the younger language, only adhering to articulatory constraints at a later stage, as predicted by the findings of Brentari et al. (2012); and (3) whether the manner of movement and path direction elements in classifier constructions are overlaid simultaneously on one another or whether they are isolated into discrete sequential linguistic units, as reported for early Nicaraguan Sign Language (Senghas et al. 2004). The study's findings differ from expectations raised by other research, reminding us that sign languages can take different paths of emergence. The methodology provides a good model for statistical analyses and careful comparative work across sign languages.

#### **3. Shared Context and Variability**

**Katie Mudd**, **Connie de Vos**, and **Bart de Boer** investigate the question of whether social structure affects the degree of lexical variation in the emergence of sign language. Evidence from signing communities supports this, with smaller, more insular communities typically displaying a higher degree of lexical variation compared with larger, more dispersed, and diverse communities. These findings are in line with studies of spoken languages, where languages with fewer speakers have been shown to tolerate more lexical irregularity. They focus on how shared context, facilitating the use of iconic signs, permits the retention of lexical variation in the emergence of language. They present the results of their own computational agent-based model in detail, which encompasses both shared context and population size, to tease apart the contributions of the two factors. They take care to link the model to real-world examples. After discussing several possible improvements to the model, they conclude that it does provide support for the roles of the social factors of both population size and shared context in influencing lexical variability in a language.

#### **4. Vulnerability of Emerging Sign Languages**

**Marah Jaraisy** and **Rose Stamp** focus on the language contact situation between two sign languages in Kufr Qassem, Israel. At present, third-generation deaf signers in Kufr Qassem are exposed to the local sign language, Kufr Qassem Sign Language (KQSL), and the dominant sign language of the wider Israeli deaf community, Israeli Sign Language (ISL), both of which emerged around 90 years ago. The authors note that there are currently about 120 deaf Kufr Qassem signers in the community, and that the school system there adopted ISL from early on, social factors that could influence the outcome they report. Third- and fourth-generation deaf people in Kufr Qassem are also exposed to ISL in the wider deaf community, within the medical, sports, legal, and interpreting services, as well as on social media. Jaraisy and Stamp analyzed the signing of twelve deaf signbilinguals from Kufr Qassem whilst engaging in a semi-spontaneous task in three language conditions: (1) with another bilingual signer, (2) with a monolingual KQSL signer, and (3) with a monolingual ISL signer. The results demonstrate that KQSL–ISL sign-bilinguals show a preference for ISL in all conditions, even when paired with a monolingual KQSL signer. They conclude that the degree of language shift in Kufr Qassem is considerable. KQSL may be endangered due to the risk of social and linguistic mergence of the KQSL community with the larger surrounding ISL community.

#### **5. Comparing Emerging Sign Languages and Creoles**

**John McWhorter** compares what we know about the emergence of spoken and signed languages in order to find evidence for fundamental properties of language. Although no known spoken languages have emerged de novo, creole languages, whose first native speakers do not have access to native-speaker input, can profitably be viewed as cases of the re-emergence of language. Sign languages have been compared with creoles in structure (Fischer 1978); however, because the vast majority of signers have non-signing, hearing parents, sign languages have also been characterized as being re-creolized in every generation (Newport 1981).

McWhorter looks at six grammatical features that have been singled out in the literature on the transition from pidgin to creole languages, finding that three of them are also found in emerging sign languages, suggesting that these three are common to all emerging languages, regardless of modality.

Although many creoles exhibit SVO word order, McWhorter concludes that this may be heavily influenced by the source language, which, in many known instances, is an SVO European language. Emerging sign languages are less consistent, leading McWhorter to conclude that the jury is still out on this issue.

On the question of determiners, both definite and indefinite, McWhorter finds evidence for the earlier emergence of indefinites, which he suggests is due to the earlier emergence of overt marking for new information (indefinites) before the overt marking of old information (definites), although the data are admittedly somewhat sparse.

Subordinate clauses are found in all creoles and most have overt markers of syntactic complementation, although not all pidgins do. Although members of the very first generation of emerging sign languages do not always exhibit sentence embedding, it has been widely reported for most sign languages, suggesting that it emerges quickly and may be universal.

When it comes to tense and aspect, most creoles have markers for past, progressive, and future. Aspect marking is found in all but the younges<sup>t</sup> sign languages; however, tense marking is not, which leads McWhorter to conclude that aspect is more fundamental to human language.

Inflection is sparse in creole languages and slow to emerge when it does, whereas it emerges very early in sign languages. McWhorter follows the literature (e.g., Aronoff et al. 2005) in concluding that the early emergence of inflection in sign languages is a consequence of the modality.

Finally, McWhorter discusses semantic opacity in derivational morphology, and concludes that this is a function of language age and lexicalization, not of the language capacity itself.

## **6. Conclusions**

Late in the 20th century, linguists began to suspect the possible value of sign language emergence for the study of human language in general. This Special Issue brings together research on a broader array of emergen<sup>t</sup> phenomena in sign languages than has ever been assembled in one place before. The articles provide a rich spectrum of new data and new insights into emerging sign language phenomena, fulfilling the promise of that earlier suspicion.

**Author Contributions:** The three authors made equal contributions to this editorial. All authors have read and agreed to the published version of the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
