In a series of connectionist computational models, which learned to map phonological forms of words onto meaning through an associative learning mechanism, Gasser  demonstrated that, as the size of the vocabulary increased, arbitrariness in the mappings between inputs and outputs of the model resulted in better learning. This was designed to investigate sound symbolism, a “potential for words to ‘naturally’ denote their meanings” (Cuskley, et al., 2017). We related each individual monomorphemic word's systematicity to the estimated age at which it was acquired, controlling for other psycholinguistic variables  using multiple linear regression. Figure 5. Reflecting properties of the referent in spoken forms of these words would necessitate reducing the distinctiveness in the sounds of the words—sound similarity can only be accomplished by changing the same signal dimensions as are used to ensure distinctiveness. Language and Linguistics: The Key Concepts (2nd ed.). If the systematicity of the vocabulary is confined to, and driven by, a small set of clusters—illustrated in the peaks of figure 3—then the distribution of systematicity should exhibit divergence from the distribution of individual words' systematicity when words' meanings are randomly reassigned, as in the randomization for the Mantel test in the previous section. For mapping from form onto such category levels, systematicity in the spoken word is beneficial [21,59], but for the more specific task of individuating words' meanings, arbitrariness is advantageous, at least for larger vocabularies . (Online version in colour. One possible driver of the age of acquisition results is the different distribution of nouns and verbs at different stages of language acquisition—a large proportion of early-acquired words are nouns. Note that this calculation assesses the relative iconicity of words. This mechanism could facilitate acquisition not only of particular sound–meaning mappings, but also the knowledge that there are mappings between sounds and meaning . Words with proposed common roots in one or more of Old English, Old French, Old Norse, Greek, Latin, Proto-Germanic or Proto-Indo-European were omitted. Cruz-Ferreira, M. & Abraham, S. (2006). The first level of arbitrariness highlights the fact that there is no inherent link between the form of a word or the sounds that constitute a word, and the meaning of that word. Theme Issue ‘Language as a multimodal phenomenon: implications for language learning, processing and evolution’ compiled and edited by Gabriella Vigliocco, Pamela Perniss, Robin L. Thompson and David Vinson. Journal of Consciousness Studies, 8(1), 3–34. It was found that the Bouba-kiki effect didn’t apply to children under 6 years old (Maurer, D., Pathman, T., & Mondloch, C. J., 2006). Similarly, Walker et al. They found that, of 46 phonaesthemes proposed by Hutchins  as present in the English language, 27 were statistically significant clusters, including sn- and gl-. Figure 4. St Benedict introduced too into the monastic life the idea of law and order, of rule binding on the abbot no less than on the monks; thus he reduced almost to a vanishing point the element of arbitrariness, or mere dependence on the abbot's will and whim, found in the earlier rules. Table 1.Correlations between different implementations of measures of sound similarity and meaning similarity for each word set. Nicholas, though he had never seen Ilagin, with his usual absence of moderation in judgment, hated him cordially from reports of his arbitrariness and violence, and regarded him as his bitterest foe. Systematicity by age of acquisition. Mean and standard error for systematicity of words binned by each year of age of acquisition, indicating that words acquired early tend to be more systematic. A fully arbitrary vocabulary is unlikely to be a stable feature of natural languages, because form-to-meaning correspondences are shaped by cultural evolutionary processes which favour not just discriminability but also learnability and communicative utility.