Search for: All records

IntroductionWhy is it that phonologies exhibit greater dispersion than we might expect by chance? In earlier work we investigated this using a non-linguistic communication game in which pairs of participants sent each other series of colors to communicate a set of animal silhouettes. They found that above-chance levels of dispersion, similar to that seen in vowel systems, emerged as a result of the production and perception demands acting on the participants. However, they did not investigate the process by which this dispersion came about. MethodTo investigate this we conducted a secondary statistical analysis of the data, looking in particular at how participants approached the communication task, how dispersion emerged, and what convergence looked like. ResultsWe found that dispersion was not planned from the start but emerged as a large-scale consequence of smaller-scale choices and adjustments. In particular, participants learned to reproduce colors more reliably over time, paid attention to signaling success, and shifted towards more extreme areas of the space over time. ConclusionThis study sheds light on the role of interactive processes in mediating between human minds and the emergence or larger-scale structure, as well as the distribution of features across the world's languages. 

We investigated the emergence of dispersion in phonological systems using an established experimental paradigm in which pairs of participants play a non-linguistic communication game, taking turns to select discrete colors from a continuous underlying space and send them to each other to communicate animal silhouettes. Over time participants established sets of signals made up of combinatorial color units, analogous to the phonemes of natural language. This allowed us to investigate the role of interactive pressures on the emergence of organizational structure in phonological inventories, principally dispersion. We manipulated minimum signal length (as a means of investigating the role of coarticulation) and the presence of probabilistic noise. We also manipulated the nature of the underlying color space. There was an effect of colorspace but not of noise or minimum signal-length. However, dispersion occurred at above-chance levels in all conditions. Our results provide evidence for the role of communicative interaction in the emergence and cultural evolution of phonological structure. 

Language is subject to a variety of pressures. Recent work has documented that many aspects of language structure have properties that appear to be shaped by biases for the efficient communication of semantic meaning. Other work has investigated the role of social pressures, whereby linguistic variants can acquire positive or negative evaluation based on who is perceived to be using them. While the influence of these two sets of biases on language change has been well documented, they have typically been treated separately, in distinct lines of research. We used a miniature language paradigm to test how these biases interact in language change. Specifically, we asked whether pressures to mark social meaning can lead linguistic systems to become less efficient at communicating semantic meaning. We exposed participants to a miniature language with uninformative constituent order and two dialects, one that employed case and one that did not. In the instructions, we socially biased participants toward users of the case dialect, users of the no-case dialect, or neither. Learners biased toward the no-case dialect dropped informative case, thus creating a linguistic system with high message uncertainty. They failed to compensate for this increased message uncertainty even after additional exposure to the novel language. Case was retained in all other conditions. These findings suggest that social biases not only interact with biases for efficient communication in language change but also can lead to linguistic systems that are less efficient at communicating semantic meaning. 

Like all modern Celtic languages Welsh exhibits initial consonant mutation with both lexical and morphosyntactic triggers. Owing to the complexity of the system and the sociolinguistic situation of Welsh, change and variation in the system seems inevitable, and evidence for change has been observed in production. Less work, however, has focused on speakers’ attitudes and expectations in perception. We used an online auditory acceptability judgement survey to investigate expectations for different morphosyntactic soft-mutation triggers. Respondents listened to sentences with canonical and non-canonical mutation patterns and used Likert scales to indicate for each sentence whether they would use the same pattern themselves and whether they would expect it from others. Almost all respondents expected some variation, even in their own production, but two main clusters of respondents could be identified: “Conservative” respondents whose expectations were close to canonical mutation patterns and “Variable” respondents whose expectations were considerably more flexible. First-language status was the only demographic variable to predict respondent attitudes, suggesting that L2 Welsh speakers accept noncanonical mutation to a greater extent than L1 Welsh speakers. We also compared different mutation triggers, with the tentative conclusion that apparently identical triggers may not in fact be identical for all speakers, and that trigger transparency may be an important factor in predicting variability. 

Names for colors vary widely across languages, but color categories are remarkably consistent. Shared mechanisms of color perception help explain consistent partitions of visible light into discrete color vocabularies. But the mappings from colors to words are not identical across languages, which may reflect communicative needs—how often speakers must refer to objects of different color. Here we quantify the communicative needs of colors in 130 different languages by developing an inference algorithm for this problem. We find that communicative needs are not uniform: Some regions of color space exhibit 30-fold greater demand for communication than other regions. The regions of greatest demand correlate with the colors of salient objects, including ripe fruits in primate diets. Our analysis also reveals a hidden diversity in the communicative needs of colors across different languages, which is partly explained by differences in geographic location and the local biogeography of linguistic communities. Accounting for language-specific, nonuniform communicative needs improves predictions for how a language maps colors to words, and how these mappings vary across languages. Our account closes an important gap in the compression theory of color naming, while opening directions to study cross-cultural variation in the need to communicate different colors and its impact on the cultural evolution of color categories. 

Corpus data suggests that frequent words have lower rates of replacement and regularization. It is not clear, however, whether this holds due to stronger selection against innovation among high-frequency words or due to weaker drift at high frequencies. Here, we report two experiments designed to probe this question. Participants were tasked with learning a simple miniature language consisting of two nouns and two plural markers. After exposing plural markers to drift and selection of varying strengths, we tracked noun regularization. Regularization was greater for low- than for high-frequency nouns, with no detectable effect of selection. Our results therefore suggest that lower rates of regularization of more frequent words may be due to drift alone. 

Labels may play a role in the formation and acquisition of ob- ject categories. We investigated this using a free-categorization task, manipulating the presence or absence of labels and whether labels were random or reinforced one of two alterna- tive categorization cues (taxonomic or thematic relationships). When labels were absent, participants used thematic and taxo- nomic cues equally to categorize stimuli. When present, labels were used as the primary cue for category formation, with ran- dom labels leading participants to attend less to taxonomic and thematic relations between stimuli. When labels redundantly reinforced either thematic or taxonomic cues, the use of the cue in question was boosted along with the use of labels as a cue for categorization. Most interestingly, in spite of pre- viously observed associations between labels and taxonomic grouping, labels did not preferentially boost the use of either taxonomic or thematic cues in comparison with the other. 

We investigated the emergence of register-like indexical associations, whereby linguistic forms that are associated with groups of speakers acquire novel associations with contextual features of those groups. We employed an artificial-language paradigm in which participants were exposed to an “alien” language spoken by two alien species wearing two different ceremonial outfits. The language varied with respect to plural suffixes, such that one suffix was associated reliably with one species and outfit in training. We then tested participants on what associations they had acquired. In two experiments we manipulated which aliens wore which outfits in the test phase. Regardless of condition or length of training, participants associated suffixes strongly with aliens rather than clothing. In a third experiment we introduced a new alien species in the test phase. For these aliens, which participants had not seen during training, participants made a clear association based on outfit. These results show clearly ranked indexical (or proto-indexical) associations on the part of participants and lay clear groundwork for the experimental investigation of the emergence of indexical social meaning in language.