Lexical Iconicity is differentially favored under transmission in a new sign language: The effect of type of iconicity

Abstract

Observations that iconicity diminishes over time in sign languages pose a puzzle--why should something so evidently useful and functional decrease? Using an archival dataset of signs elicited over 15 years from 4 first-cohort and 4 third-cohort signers of an emerging sign language (Nicaraguan Sign Language), we investigated changes in pantomimic (body-to-body) and perceptual (body-to-object) iconicity. We make three key observations: (1) there is greater variability in the signs produced by the first cohort compared to the third; (2) while both types of iconicity are evident, pantomimic iconicity is more prevalent than perceptual iconicity for both groups; and (3) across cohorts, pantomimic elements are dropped to a greater proportion than perceptual elements. The higher rate of pantomimic iconicity in the first-cohort lexicon reflects the usefulness of body-as-body mapping in language creation. Yet, its greater vulnerability to change over transmission suggests that it is less favored by children's language acquisition processes.

Keywords: Language emergence; Nicaraguan Sign Language; iconicity; vocabulary.

Figure 1.

Examples of types of iconicity. Pantomimic signs entail a body-to-body correspondence, and any movement of the articulators corresponds to (A) action features of the referent, as in pantomiming the baring of teeth and swiping movement of the hand for LION, or (B) someone enacting interacting with the referent, as in cupping the hands near the mouth and making biting movements for CORN. (C) Perceptual signs entail a correspondence between the articulators and observable features of the referent, such as its size and shape, and the sign movement corresponds to the extent or movement of the referent, such as flat hands swinging outward for HAMMOCK. A sign was coded as (D) both if it simultaneously included pantomimic and perceptual iconicity, such as a flat hand representing the shape of a knife (perceptual) with a simultaneous motion that demonstrates a cutting movement (pantomimic) for PLANTAIN.

Figure 2.

An example of a compound sign. Here, the two-sign compound WATERMELON includes one pantomimic sign-unit in which the signer imitated holding and eating from a slice of watermelon, followed by a both sign-unit in which the signer pantomimed spitting out a seed with his mouth, while simultaneously tracing the path of the seed perceptually with the index finger. This compound sign was accordingly coded as pantomimic + both.

Figure 3.

Variability in the signs produced for each concept by 4 first-cohort and 4 third-cohort signers of NSL. A score of 0 indicates that all signers produced the same sign; a score of 1 indicates that each signer produced a different sign. There is significantly more variability among the first-cohort signers than the third-cohort signers.

Figure 4.

The different signs elicited for the concept horse. This concept elicited highly variable signed expressions from the four first-cohort signers, who produced four different sign variants, and less variability among the third-cohort signers, with three of the four signers producing the same form. The fourth signer produced a slightly different version, in which the two hands assumed a similar handshape.

Figure 5.

Average proportion of participant responses exhibiting sign-units with each type of iconicity, by cohort. Multi-sign compounds counted toward multiple types e.g., a multi-sign compound that included a pantomimic sign-unit and a both sign-unit counted toward the proportion of pantomimic and to the proportion of both. Pantomimic iconicity was the most prevalent type across cohorts, and was the type that decreased the most as the language was passed from the first to the third cohort.

Figure 6.

Proportion of signs that changed from the first cohort to the third cohort, as a result of dropping or adding sign-units exhibiting each type of iconicity. Negative values represent dropping a sign from a multi-sign compound; positive values represent adding a sign to form a multi-sign compound.

Figure 7.

An example of a multi-sign compound dropping an iconic element in the third cohort relative to the first. (A) A first-cohort signer produces a single sign JEALOUS that includes the pantomimic element of biting a knuckle of her index finger. (B) A first-cohort signer produces a multi-sign compound JEALOUS that includes biting a knuckle followed by touching the knuckle to the chin. (C) A third-cohort signer produces a single sign JEALOUS that has dropped the pantomimic biting element, retaining only the movement of the knuckle to the chin seen in (B).