The learning bias for cross-category harmony is sensitive to semantic similarity: Evidence from artificial language learning experiments

Abstract

Cross-category harmony is one of the most well-known typological universals. It describes the tendency for syntactic heads to be ordered consistently relative to their dependents across different phrase types. Explanations for this universal vary as to whether cognitive factors play a role, or instead the tendency is due to mechanisms of language change alone. In this paper we report a series of artificial language learning experiments that aim to test a hypothesized link between cognition and cross-category harmony. As with the typological tendency itself, we find mixed evidence for harmony across different types of phrases. Specifically, learners are biased in favor of harmony between the order of verb and object and the order of adposition and noun. However, the bias for harmony between the order of verb and object and the order of adjective and noun depends on the semantic similarity between adjectives and verbs. When adjectives are active and therefore more verb-like (e.g., ‘broken'), we find harmony; when they are stative and therefore less verb-like (e.g., ‘blue'), we do not. These results suggest that the bias for cross-category harmony is not purely based on the syntactic notions of head and dependent, but reflects the interaction between a general cognitive bias for simplicity and cross-category similarity (Culbertson and Kirby, 2016; Culbertson and Kirby, 2022).

Does degree of innovation modulate the influence of cognitive biases on language structure?

“…Taking this a step further, training could also be conducted on one category of dependents and tested on a different category of dependents, taking the task from a generalisation to an extrapolation context. For example, training participants on the order between adjectives and nouns and then testing them on the order of genitives and nouns, similar to what is done in Wang et al (2023) where participants extrapolate the order between ad-jectives and nouns to the order between verbs and objects (and vice versa).…”

“…Similarly, children do not learn all linguistic categories or constructions simultaneously (Gentner, 1982;Tardif et al, 1999), but must integrate these into an existing system which already might include similar constructions and categories or not. Extrapolation is often used in experimental tasks as well, in order to see how participants use limited or ambiguous evidence to generate novel items/structures or treat novel categories (e.g., Culbertson and Adger, 2014;Finley, 2018;Saldana et al, 2021;Wang et al, 2023).…”

“…For example, Wang et al (2023) found that participants will extrapolate the word order from one phrase type to another as long as the meanings involved were sufficiently similar. 3 This suggests that a system-wide bias like harmony applies not just in learning, but also in contexts that are higher on the Scale of Innovation.…”

Category-specific and system-wide preferences in competition: Evidence from noun phrase harmony

“…Recent research has explored the way that cognitive biases, which favour or disfavour certain linguistic structures, have contributed to the cross-linguistic typological tendency for harmonic word order (Christiansen, 2000;Culbertson, 2012;Culbertson & Kirby, 2016;Wang et al, 2023). This work includes experimental, computational and corpus-based studies examining how these structural biases emerge, and how they affect linguistic behaviour across different age groups and structures.…”

“…Generally, artificial language learning experiments examining this pattern have found that people tend to prefer harmonic languages to non-harmonic ones: both adults and children learn, reproduce and regularise (i.e., extend) harmonic patterns rather than non-harmonic ones (Culbertson & Newport, 2017;Culbertson et al, 2012), even if their native languages are non-harmonic (Culbertson, Franck, et al, 2020;Culbertson & Newport, 2015;Wang et al, 2023).…”