How diverse is child language acquisition research?

“For this, we used the glm and predict functions of the lme4 package (version 1.1–27.1, D. Bates et al., 2015).”

“A key feature of natural languages is their vast diversity, which is evident at every level of analysis (Evans & Levinson, 2009).”

“Language also asserts our social identity as members of a particular culture or cultures (Gallois et al., 2005; Giles et al., 1991), and in minority groups its preservation is linked to higher wellbeing (Gibson et al., 2021; Hallett et al., 2007).”

“Work on highly inflected languages has challenged theoretical approaches to morphological acquisition that postulate the use of abstract rules (Marcus et al., 1992; Pinker, 1999), and instead provide evidence in favour of schema-based generalisations (e.g. Dabrowska & Szczerbinski, 2006; Engelmann…”

“…the estimate drastically: developmental psychology journals appear to have an even more extreme bias than we see in child language acquisition (see Nielsen et al., 2017) and coverage in major child language conferences is quite similar to the larger set of findings we report here (Kelly &…”

“Cross-cultural studies of children’s linguistic environment continue to expand the types of conditions under which children are socialised into language (Brown, 2012; Casillas et al., 2020; de León, 2012; Ochs & Schieffelin, 2012).”

“Reviewing progress in the field of language documentation (which emerged as a response to rapid rates of language loss, Hale, 1992; Himmelmann, 1998), Seifart et al. (2018) reported that we have basic word lists for around 89% of the world’s languages, and a grammatical description of some sort for…”

“Some big languages exhibit greater variation within varieties than others (e.g. Arabic has been argued to have the same diversity as the Romance language family, Holes, 2004, although Modern Standard Arabic exists as a spoken register and literary standard).”

“Work on K’iche’ (Pye & Quixtan Poz, 1988), Zulu (Suzman, 1987), Sesotho (Demuth, 1989) and Inuktitut (Allen & Crago, 1996) falsified arguments that the passive voice is late-acquired due to the delayed maturation of components of Universal Grammar (Borer & Wexler, 1987).”

“…nominative experiencers, participial passives, negative pronouns and a lack of verbal negation, and verb fronting in polar interrogatives (for a full list of ‘Standard Average European’, see Haspelmath, 2001; on the exceptionality of north-western European languages, see Cysouw, 2011).”

“Language also asserts our social identity as members of a particular culture or cultures (Gallois et al., 2005; Giles et al., 1991), and in minority groups its preservation is linked to higher wellbeing (Gibson et al., 2021; Hallett et al., 2007).”

“Languages diversify unevenly across the globe, with greater diversity within the Tropics (Gorenflo et al., 2012), far away from the Global North countries that produce most of our research.”

“Work on K’iche’ (Pye & Quixtan Poz, 1988), Zulu (Suzman, 1987), Sesotho (Demuth, 1989) and Inuktitut (Allen & Crago, 1996) falsified arguments that the passive voice is late-acquired due to the delayed maturation of components of Universal Grammar (Borer & Wexler, 1987).”

“Our field has a justifiably proud tradition of crosslinguistic work, as is most prominent in Slobin’s (1985–1997) Crosslinguistic Study of Language Acquisition series and in other landmark projects like Berman and Slobin’s (1994) crosslinguistic ‘frog story’ narrative project and MacWhinney and Bates’ (1989) Crossling…”

“For instance, Jaeger and Norcliffe (2009) reported that adult language production studies have covered only 0.6% of the world’s languages.”

“Cross-cultural studies of children’s linguistic environment continue to expand the types of conditions under which children are socialised into language (Brown, 2012; Casillas et al., 2020; de León, 2012; Ochs & Schieffelin, 2012).”

“Work on K’iche’ (Pye & Quixtan Poz, 1988), Zulu (Suzman, 1987), Sesotho (Demuth, 1989) and Inuktitut (Allen & Crago, 1996) falsified arguments that the passive voice is late-acquired due to the delayed maturation of components of Universal Grammar (Borer & Wexler, 1987).”

“…approaches to morphological acquisition that postulate the use of abstract rules (Marcus et al., 1992; Pinker, 1999), and instead provide evidence in favour of schema-based generalisations (e.g. Dabrowska & Szczerbinski, 2006; Engelmann et al., 2019; Forshaw, 2021; Granlund et al., 2019).”

“However, many aspects of working on understudied languages are time-intensive (and in the case of endangered languages, particularly difficult, Kelly et al., 2015), such that we will never achieve a representative sample unless we make drastic changes to the way we collect data and who collects it.”

“Our field has a justifiably proud tradition of crosslinguistic work, as is most prominent in Slobin’s (1985–1997) Crosslinguistic Study of Language Acquisition series and in other landmark projects like Berman and Slobin’s (1994) crosslinguistic ‘frog story’ narrative project and MacWhinney and Bates’ (1989) Crossling…”

“At the same time, languages are dying at an alarming rate (Evans, 2010).”

“…the utility of Pinker’s (1984, 1989) innate linking rules, and the inherent complexity and variability in ergative marking across languages questioned the likelihood that they could be described by parameter-setting approaches (Pye, 1990; Van Valin, 1992; see also papers in Bavin & Stoll, 2013).”

“…that heavily interface with culture, such as pragmatics and discourse (e.g. event packaging in narrative, Berman & Slobin, 1994; politeness, Chang et al., 2021), nonverbal communication (e.g. gesture, Özyürek et al., 2008) and language and cognition (e.g. neo-Whorfian work, Majid et al., 2004).”

“This skew means that we know much less about features more common outside of European sprachbund, such as tone (Singh & Fu, 2016), polysynthesis (Kelly et al., 2014; Mithun, 1989), obviation (Henke, 2021), ergativity (Bavin & Stoll, 2013) and clause chaining (Sarvasy & Choi, 2020), to name but a few.”

“…and ultimately falsified the assumption that the prosodic and grammatical modifications observed in ‘motherese’ in languages like English, German and French were a universal component of the child’s input (Bernstein-Ratner & Pye, 1984; Ochs & Schieffelin, 1984; Pye, 1986; see also Ingram, 1995).”

“…of language proficiency and tests of cognitive function (e.g. memory, attention) most commonly exist for bigger, well-studied languages, allowing researchers to ask questions about the sources and consequences of individual differences in acquisition (E. Bates et al., 1995; Kidd & Donnelly, 2020).”

“…and ultimately falsified the assumption that the prosodic and grammatical modifications observed in ‘motherese’ in languages like English, German and French were a universal component of the child’s input (Bernstein-Ratner & Pye, 1984; Ochs & Schieffelin, 1984; Pye, 1986; see also Ingram, 1995).”

“Articles on non-Indo-European languages also appear in domestic or specialised linguistics journals (e.g. Lillo-Martin et al., 2016; Meakins & Algy, 2016; Pye, 2013).”

“This skew means that we know much less about features more common outside of European sprachbund, such as tone (Singh & Fu, 2016), polysynthesis (Kelly et al., 2014; Mithun, 1989), obviation (Henke, 2021), ergativity (Bavin & Stoll, 2013) and clause chaining (Sarvasy & Choi, 2020), to name but a few.”

“Crosslinguistically, there is an observable though not invariable preference to relativise syntactic subjects (see Lau & Tanaka, 2021).”

“This skew means that we know much less about features more common outside of European sprachbund, such as tone (Singh & Fu, 2016), polysynthesis (Kelly et al., 2014; Mithun, 1989), obviation (Henke, 2021), ergativity (Bavin & Stoll, 2013) and clause chaining (Sarvasy & Choi, 2020), to name but a…”

“Work by Campbell et al. (2013) and Seifart et al. (2018) shows that over 3000 languages are moribund, endangered or nearly extinct.”

“…the utility of Pinker’s (1984, 1989) innate linking rules, and the inherent complexity and variability in ergative marking across languages questioned the likelihood that they could be described by parameter-setting approaches (Pye, 1990; Van Valin, 1992; see also papers in Bavin & Stoll, 2013).”

“In particular, there have been exciting developments in daylong recording technology (Casillas & Cristia, 2019), and we can hope for a day when much of the transcription bottleneck is alleviated by good speech-to-text transcription.”

“…nominative experiencers, participial passives, negative pronouns and a lack of verbal negation, and verb fronting in polar interrogatives (for a full list of ‘Standard Average European’, see Haspelmath, 2001; on the exceptionality of north-western European languages, see Cysouw, 2011).”

“…processing in languages like Cantonese, Mandarin and Tagalog has shown that online parsing choices are intimately tied to input frequency (e.g. Chan et al., 2018; Garcia, Garrido Rodriguez & Kidd, 2021; Yang et al., 2020), and cannot be explained solely with reference to abstract,…”

“Crystal (2014) reports slightly different numbers to Slobin (2014), but the trends are the same.”

“…and ultimately falsified the assumption that the prosodic and grammatical modifications observed in ‘motherese’ in languages like English, German and French were a universal component of the child’s input (Bernstein-Ratner & Pye, 1984; Ochs & Schieffelin, 1984; Pye, 1986; see also Ingram, 1995).”

“Work on sign languages, a large proportion of which are endangered (Woodward, 2018), places crucial constraints on theorising and reveals how the core features of the language faculty emerge independent of modality (Morgan, 2014; Sandler & Lillo-Martin, 2006).”

“Work on K’iche’ (Pye & Quixtan Poz, 1988), Zulu (Suzman, 1987), Sesotho (Demuth, 1989) and Inuktitut (Allen & Crago, 1996) falsified arguments that the passive voice is late-acquired due to the delayed maturation of components of Universal Grammar (Borer & Wexler, 1987).”

“Articles on non-Indo-European languages also appear in domestic or specialised linguistics journals (e.g. Lillo-Martin et al., 2016; Meakins & Algy, 2016; Pye, 2013).”

“Or as Pye (2021) puts it: ‘the data needed to construct a representative sample of languages to test acquisition theories in a meaningful way do not exist’ (p. 454).”

“It also means we have limited understanding of how children might acquire typologically rarer phenomena (e.g. symmetrical ‘Philippine-style’ voice, see Garcia & Kidd, 2020), which are existence proofs of what is possible in natural language and may be particularly challenging to theories built…”

“…45 spoken languages across its monolingual and multilingual corpora (approximately 53% of which are Indo-European languages).3 The goal of crosslinguistic research is to identify universal and language-specific components of language acquisition (Slobin, 1973, 1985–1997; Slobin & Bowerman, 2007).”

“…series and in other landmark projects like Berman and Slobin’s (1994) crosslinguistic ‘frog story’ narrative project and MacWhinney and Bates’ (1989) Crosslinguistic Study of Sentence Processing (for overviews, see Bavin, 1995; Berman, 2014; Bowerman, 2011; Lieven, 1994; Lieven & Stoll, 2009).”

“Our own work on children’s processing in languages like Cantonese, Mandarin and Tagalog has shown that online parsing choices are intimately tied to input frequency (e.g. Chan et al., 2018; Garcia, Garrido Rodriguez & Kidd, 2021; Yang et al., 2020), and cannot be explained solely with reference to abstract, language-i…”

“Articles on non-Indo-European languages also appear in domestic or specialised linguistics journals (e.g. Lillo-Martin et al., 2016; Meakins & Algy, 2016; Pye, 2013).”

“Our field has a justifiably proud tradition of crosslinguistic work, as is most prominent in Slobin’s (1985–1997) Crosslinguistic Study of Language Acquisition series and in other landmark projects like Berman and Slobin’s (1994) crosslinguistic ‘frog story’ narrative project and MacWhinney and Bates’ (1989) Crossling…”

“…skew means that we know much less about features more common outside of European sprachbund, such as tone (Singh & Fu, 2016), polysynthesis (Kelly et al., 2014; Mithun, 1989), obviation (Henke, 2021), ergativity (Bavin & Stoll, 2013) and clause chaining (Sarvasy & Choi, 2020), to name but a few.”

“Language also asserts our social identity as members of a particular culture or cultures (Gallois et al., 2005; Giles et al., 1991), and in minority groups its preservation is linked to higher wellbeing (Gibson et al., 2021; Hallett et al., 2007).”

“In the Indo-European category, English and large Romance and Germanic languages have many articles, whereas the number for other languages is much smaller.”

“…to topics that heavily interface with culture, such as pragmatics and discourse (e.g. event packaging in narrative, Berman & Slobin, 1994; politeness, Chang et al., 2021), nonverbal communication (e.g. gesture, Özyürek et al., 2008) and language and cognition (e.g. neo-Whorfian work, Majid et…”

“Work on sign languages, a large proportion of which are endangered (Woodward, 2018), places crucial constraints on theorising and reveals how the core features of the language faculty emerge independent of modality (Morgan, 2014; Sandler & Lillo-Martin, 2006).”

“Crucially, this diversity is relevant not only for the language sciences (e.g., [3,7]) but also for the broader study of cognitive science, as differences in language”

“In this way, infant language experience, although rarely reported (Kidd & Garcia, 2022), can have far-reaching effects on basic behaviors that form the methodological back-bone of the field (see Byers-Heinlein et al., 2019 for a discussion of this issue).”

“At the same time, we acknowledge that significant gaps remain in the availability of CDIs across the world’s languages (Kidd and Garcia, 2022).”

“D” samples, Henrich, Heine, & Norenzayan, 2010; Kidd & Garcia, 2022; Nielsen, Haun, Kärtner, & Legare, 2017).”