Research

I study how children build the meanings of their first words; and how the field's measures, samples, and procedures shape what we think we know about that process. My work uses meta-analysis, cross-linguistic data, and behavioral experiments to ask which findings about early word learning generalize, and which don't.

Research Interests

  • Language Acquisition
  • Cognitive Development
  • Cross-cultural developmental psychology
  • Meta-science, heterogeneity, and psychological measurements

Current Projects

1. Meta-analysis of the shape bias as a word-learning strategy

The shape bias has been studied for decades, with creative experiments giving us real insight into how young children acquire and extend early words (mostly nouns). But the literature has been hard to consolidate; and therefore hard to build on; because studies use such heterogeneous procedures, stimuli, and measures.

In this project, we use meta-analysis to synthesize the existing evidence and identify covariates that explain the variation across studies. The goal is to better adjudicate between competing theoretical accounts of a phenomenon; the shape bias; that's often treated as a foundational learning bias for vocabulary development.

Check: Abdelrahim, S. O, & Frank, M. C. (2024). Examining the robustness and generalizability of the shape bias: a meta-analysis. Proceedings of the Annual Meeting of the Cognitive Science Society, 46. Read here

2. Do early lexical statistics explain cross-cultural differences in word extension?

US English-speaking children show a stronger word-extension shape bias than children learning some East Asian languages. Why? One hypothesis is that the early vocabularies themselves differ; that the statistics of nouns young children hear and learn vary across languages in ways that shape generalization. Across 16 languages, we ask whether such variation actually exists, and how much of the cross-cultural pattern it could plausibly explain.

Check: Abdelrahim, S. O, & Frank, M. C. (2024). Limited cross-linguistic variation in the lexical statistics of nouns in early vocabulary (BUCLD49 2024, Boston, USA)

Check: Lexical Statistics in Early Noun Vocabularies: A Cross-Linguistic and Rater-Origin Perspective. Samah Abdelrahim, Jongmin Jung, Claire Lee, Eon-Suk Ko, Michael Frank (BUCLD50 2025, Boston, USA)

3. Measurement of the shape bias: age, stimuli, and procedure variation

Different studies of the shape bias use different children, different objects, and different tasks. We ask how much of the apparent inconsistency in the literature is explained by these procedural choices; testing children of varying ages with systematically varied stimuli and procedures within a single design.

Check: Investigating heterogeneity in shape bias: a study on procedural, stimuli, and age-related variations. Samah Abdelrahim, Sadio Abdi, Meesha Ryan, Michael Frank (The 15th Annual BCCCD Conference, January 9-11 2025 - BCCCD25) (YouTube video here)

4. What exactly is a complex object? And what does complexity even mean? Implications for early word learning

A new line of work asking what "complexity" actually means for an object; and what that has to do with how children learn its name. More soon!

Papers & Conference Talks

In preparation

  • Word extension tasks as a measurement of the shape bias. Abdelrahim et al. (in prep)
  • Lexical statistics in early noun vocabularies across 16 languages. Abdelrahim, Jung, Ko, & Frank. (in prep)

Conference papers & posters

  • Abdelrahim, S., Jung, J., Lee, C., Ko, E.-S., & Frank, M. C. (2025). Lexical statistics in early noun vocabularies: a cross-linguistic and rater-origin perspective. BUCLD50 2025, Boston, USA.
  • Abdelrahim, S., Abdi, S., Ryan, M., & Frank, M. C. (2025). Investigating heterogeneity in shape bias: a study on procedural, stimuli, and age-related variations. The 15th Annual BCCCD Conference (BCCCD25), January 9–11, Budapest, Hungary.
  • Abdelrahim, S. O, & Frank, M. C. (2024). Limited cross-linguistic variation in the lexical statistics of nouns in early vocabulary. BUCLD 2024, Boston, USA.
  • Abdelrahim, S. O, & Frank, M. C. (2024). Examining the robustness and generalizability of the shape bias: a meta-analysis. Proceedings of the Annual Meeting of the Cognitive Science Society, 46. Sydney, Australia. Read here
  • Bisbee, N., Tang, J. E., Yu, S. J., Lyu, Z. X., Abdelrahim, S., & Gordon, P. (July 7–10, 2022). Relations between exact number and exact equality: developmental and cross-cultural perspectives. [Conference Poster]. International Congress on Infant Studies (ICIS) 2022 XXIII Biennial Congress, Ottawa, Canada.
  • Tang-Lonardo, J., Bisbee, N., Jain, M., Kirby, E., Kim, S. B., Abdelrahim, S., Gerami, S., Sezcon-Cepeda, D., Coffel, M., & Gordon, P. (May 26–29, 2022). The neural mechanisms of parallel individuation and numerical approximation. [Conference Poster]. Association for Psychological Science (APS) 2022 Annual Convention, Chicago, IL, USA.
  • Tang, J. E., Bisbee, N., Jain, M., Kirby, E., Kim, S. B., Gerami, S., Sezcon-Cepeda, D., Gilchrist, K., Abdelrahim, S., Coffel, M., & Gordon, P. (July 27–30, 2022). The neurobehavioral basis of parallel individuation and numerical approximation. [Conference Poster]. Cognitive Science Society 2022, 44th Annual Conference, Toronto, Canada.