About

Catherine Snow is the John H. and Elisabeth A. Hobbs Research Professor of Cognition and Education at Harvard Graduate School of Education. Her expertise focuses on language and literacy development in children, particularly how oral language skills are acquired and their relationship to literacy outcomes. Her current research includes studying how Boston Public School early childhood classrooms support children's development and participating in a long-standing research-practice partnership with the Strategic Education Research Partnership (SERP), which develops curricular tools to support teachers in implementing innovative classroom practices. Snow has contributed to the development of Word Generation, a discussion-based academic language and literacy program that has been shown to improve middle-school literacy outcomes, especially for students from language-minority homes. She has received numerous awards, including the Morningstar Teaching Award at Harvard and an Honorary Degree from the University of Nijmegen, and has held leadership roles such as Chair of the RAND Reading Study Group and President of the American Educational Research Association. Her work also includes cofounding the Child Language Data Exchange System and leading projects aimed at improving preservice teacher training and early childhood education, including efforts in China to align curriculum with classroom quality and instructional outcomes.

Research topics

• Psychology
• Linguistics
• Mathematics education
• Developmental psychology
• Computer science

Selected publications

• Individual Differences in Second-Language Ability

  2026-01-06

  book-chapter1st authorCorresponding

  The second-language abilities of 51 English speakers learning Dutch naturalistically were tested at three points during their first year in the second-language environment. The tests used reflected abilities in pronunciation, auditory discrimination, morphology, syntax, vocabulary, comprehension of running speech, fluency, and metalinguistic judgments. Factor analyses of the results revealed the emergence during the year of two major second language factors: grammar plus vocabulary and phonological ability. The vocabulary tests correlated highly with tests of syntax and morphology at all test sessions. These results are related to hypotheses concerning individual differences in strategies of first-and second-language acquisition.

  PublisherDOI

• One Career, Two Career Narratives

  Cambridge University Press eBooks · 2025-02-18

  book-chapter1st authorCorresponding
  PublisherDOI

• Scaling high quality: An implementation study of Boston’s Universal Pre-K expansion to community-based programs

  Early Childhood Research Quarterly · 2025-08-18

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  PublisherDOI

• Learning English in China: The Earlier, the Better?

  International Journal of Applied Linguistics · 2025-06-22

  articleSenior author

  ABSTRACT This study examined the relationship of university students’ English proficiency to the age at which they started learning English in mainland China. With the data collected from 4530 students in 50 universities in 24 different provinces or municipalities, we employed a multiple regression model to investigate (a) whether the tested English score in the national entrance exam was predicted by the age at which the students started learning English and (b) whether the start age of English learning influences the association between time invested and learning outcome. Our results found that students who began learning English in third grade predicted significantly lower scores than those who started in kindergarten. However, no such significance of “advantage” was observed in earlier starts from kindergarten over Grade 1. Although the main effect of total learning duration was not significant, its interaction effect suggests that students who start learning later benefit more from longer durations of English input and tend to catch up quickly and show faster growth. These findings conflict with the ‘the earlier, the better’ assumption in language learning and further raise the question to what degree foreign language education should prioritize starting early versus focusing on quality and positive affect.

  PublisherDOI

• ClassBank: A Comprehensive Resource for Classroom Discourse Analysis in Education

  Elsevier eBooks · 2025-01-01

  book-chapterSenior author
  PublisherDOI

• Author response for "Learning English in China: The Earlier, the Better?"

  2025-04-24

  peer-reviewSenior author
  PublisherDOI

• From the “Here and Now” to the “There and Then”: How parent–child decontextualized conversations support early development

  Developmental Review · 2025-07-22 · 2 citations

  article
  PublisherDOI

• Priorities for New Data Collection

  Developmental Science · 2025-09-05 · 1 citations

  articleOpen accessSenior author

  Schaff, Loukatou, Cristia, and Havron (SLC&H) have contributed a fascinating and important analysis of the demographic characteristics of the child language data currently available in the CHILDES database. They were able to supplement information already on the web by soliciting further specifics from many of the original data contributors. They have identified biases in the representation of urbanization, family structure, SES, languages studied, countries represented, and multilingualism. These biases in the availability of data from rural, non-Western, low-education participants speaking non-Indo-European languages raise concerns when drawing conclusions about universality of phenomena, echoing widespread worries within psychology, sociology, and education about the dominance in research studies of data gathered only from WEIRD (Western, educated, industrialized, rich, and democratic) populations (Henrich et al. 2010). Child language data had an even more extreme bias in the 1970s, when the bulk of our transcript data came from typically developing children of English-speaking academics, often in the northeastern United States. Since then, the coverage has broadened greatly to include data from 48 languages, variations in SES, and a rich collection of types of multilingualism. Despite this growth in coverage, the database can never be truly representative of all the patterns of variation in the 2.2 billion children on the planet. This is because it would be difficult to attain fully representative coverage. Despite improvements in recording technology (LENA), automatic speech recognition (Liu et al. 2023), natural language processing (Liu and MacWhinney 2024), GenAI (Warstadt and Bowman 2022), and corpus linguistics (Baayen 2010), the collection and analysis of child language samples remains a daunting task. Barriers to data collection include privacy restrictions, researchers who are unwilling to share their data, restrictive IRB policies, lack of recognition for corpus work, logistical problems in rural areas, the need to rely on translators, and scarcity of research support. Given these limitations, the goal of eliminating the gaps so as to produce a fully balanced representation seems unattainable, at least in the near term. Fortunately, we can make productive use of the gaps and biases identified by SLC&H to guide our research. We can do this by focusing on the contrasts between universals and variation in language acquisition. This line of research begins by first proposing some universal and then collecting data that could falsify the universal. For example, SLC&H point to studies evaluating the universality of the noun bias, late passive acquisition, reduced parental input in rural communities, variations in gesture typology, or the effects of early bilingualism. In each of these areas, a universal is proposed based on evidence from current corpora, and then further data is collected that either confirms or falsifies the universal. Consider the case of the noun bias described by Gentner (2006). Studies based on samples such as the three children in Brown (1973) do indeed show an early noun bias for the English of children of educated parents in the Boston area when sampled during interviews recorded by graduate students. However, as shown by Sugárné (1970) for Hungarian, the use of verbs increases markedly and surpasses nouns when children are recorded on the playground. Moreover, as Ninio and Snow (1988) have shown, early vocabulary is rich in socially mediated terms that lie outside the noun-verb contrast. When we turn to languages outside of Indo-European, such as Chinese, Korean, or Mayan, we can see a reversal of the noun bias. Thus, both activity and language impact this feature of early vocabularies, suggesting that it may be important to explore the further effects of activity types as well as urbanization, SES, and birth order on this pattern. To cite another example, using data in CHILDES (Gleason and Ely 1997; Gleason and Greif 1983) compared the lexicon used in interactions with mothers, with fathers, and over the dinner table and found a great amount of non-overlap between these situations. Lexical non-overlap has also been documented for children learning two languages (Yip and Matthews 2007) that are used in very different settings. Although not included in this survey, language disabilities also have enormous and varied impacts on both the overall course and the details of language acquisition (Bishop 1997; Guendouzi et al. 2011). We can also propose and test universals regarding language teaching methods. WEIRD parents rely on elaborations and recasts to promote children's learning (Sokolov 1993). However, Schieffelin (1985) found that Kaluli mothers relied instead on asking children to repeat phrases after them. Studies of non-Western and rural cultures have shown that they can vary markedly in their use of praise, teasing, emotion terms, honorifics, and other routines. Even more extreme differences in parental output have been documented for groups such as the Navajo or Maya, in which direct parental input to young children is often minimal (Scollon 1976). Examples of this type could be multiplied dozens of times. However, what is missing in these reports are the detailed transcriptions of real-life interactions that would allow us to understand these patterns in greater detail. We have no shared transcript data from Kaluli, Mayan, Navajo, or Samoan that would allow us to track the effects of these variations in input. However, there are areas where such data does exist. For example, Gleason's recordings of mother, father, and dinner table talk are in CHILDES, and her published results on lexical non-overlap can be traced in further detail, as can the Yip and Matthews recordings of their bilingual subjects. For SES and ethnic group contrasts, one can look at the transcripts and audio from the Harvard HSLLD (Home-School Study of Language and Literacy Development) and a series of 12 papers analyzing these patterns. This gives us a rich picture of these contrasts in the Boston area, and we can then ask about what would be the results of a similar study conducted in Marseille, Manchester, Mombasa, Mumbai, or Mannheim. Data from rural populations and special areas could be particularly informative. For this, the representation of American, English-speaking children growing up in rural families who are eligible by family income for Head Start will increase with the imminent release of transcripts from the Early Head Start Project (Pan et al. 2005). We can study alternative patterns of language loss and maintenance as indigenous communities become increasingly linked to the global economy. To maximize our ability to understand these patterns of variation or universality, we need to create language sampling protocols that allow for cross-linguistic comparison. An example of such an effort is the Global Tales (https://talkbank.org/childes/access/GlobalTales/) project that asks children in the age range between 3 and 6 to tell stories about times when they were either happy, confused, angry, or proud, or when they had to deal with a situation that was either problematic or important. These same questions are being asked by researchers working with children from 25 countries and languages. The results so far demonstrate both variation and universality in the nature of the stories children tell. Most of the data collected so far is from middle-class children in urban settings, and adding data from rural populations and across SES levels is an important goal. Other projects working on cross-cultural and cross-linguistic comparisons include Acquisition Sketch, LITMUS, LaCoLa, Frog Stories, and PLAY. We can study universals and variation using comparisons across demographic variables. However, we also need to consider the role of individual variation in patterns of acquisition. For example, Peters (1977) contrasted children with precise articulation and those with “mush mouth”. Nelson (1973) contrasted referential and expressive children—a contrast that was then echoed in Bloom et al. (2001). Nelson (1981) further notes that children may shift from one acquisitional strategy to another across time. To examine strategies and processes in detail, Lieven, Tomasello, and colleagues collected densely sampled corpora for English, Finnish, and German. Using such data, they were able to show that, even on the level of argument structures for the English articles, acquisition is highly lexically specific, rather than driven by universal featural structures (Lieven et al. 1997). Looking back across the 50-plus years since the publication of Brown (1973), we can marvel at the growth in the availability of data on child language acquisition: from a set of transcripts from three children produced on mimeographed sheets to a world with data on thousands of children across 48 languages linked to terabytes of media. Of course, every glass in science is always half empty, and we are always striving for a fuller understanding, but it is heartening to know how much progress has been made. The careful work by SLC&H advances us still further by serving as a guide for new comparisons and by suggesting priorities for new data collection. The authors have nothing to report. The authors declare no conflicts of interest. The data that support the findings of this study are openly available in CHILDES at https://childes.talkbank.org.

  PublisherOA PDFDOI

• A video modeling intervention for teaching academic language discourse skills

  Computer Assisted Language Learning · 2025-05-15

  articleSenior author
  PublisherDOI

• Using Decoding Measures to Identify Reading Difficulties: A Meta-analysis on English as a First Language Learners and English Language Learners

  Educational Psychology Review · 2025-01-30

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  PublisherDOI

Frequent coauthors

• Christina Weiland

  35 shared

• John Locke

  32 shared

• Brian MacWhinney

  Carnegie Mellon University

  32 shared

• Anat Ninio

  29 shared

• Hollis S. Scarborough

  Haskins Laboratories

  28 shared

• Anne Van Kleeck

  The University of Texas at Austin

  28 shared

• Marilyn Jager Adams

  27 shared

• John D. Bonvillian

  Atrium Health Wake Forest Baptist

  27 shared

Labs

• Catherine Snow LabPI

Education

• PhD, Department of Psychology

  McGill University

  1971

• M.A., Department of Psychology

  McGill University

  1967

• B.A.

  Oberlin College

  1966

Awards & honors

• Morningstar Teaching Award, Harvard Graduate School of Educa…
• Honorary Degree, University of Nijmegen (2003)
• Carnegie Corporation of New York, Institute for Statewide Li…
• Charles A. Ferguson Fellow, Center for Applied Linguistics (…
• Spencer Senior Scholar Award (1999)