Bridging the Toddler Data Desert: Advancing Methods, Theory, and Diversity in Early Developmental Science

Dear Colleagues,

The field of developmental science has made significant advances in understanding infancy (0–12 months) and preschool years (3–5 years). However, there remains a striking gap in empirical data, methodological innovation, and theoretical development focused on toddlers (approximately 1–3 years)—a period marked by rapid growth in language, executive functions, social cognition, motor skills, and self-regulation. This “toddler data desert” limits our ability to build cohesive models of developmental change and identify the mechanisms underlying both typical and atypical trajectories.

The toddler period poses unique methodological and practical challenges. Toddlers are highly mobile, have variable attention spans, and often fall between research paradigms optimized for infants (e.g., preferential looking, habituation) and those used for older children (e.g., explicit tasks, self-report, structured interviews). These challenges have contributed to a disproportionate lack of studies targeting this critical developmental window—especially in areas like neuroimaging, computational modeling, longitudinal designs, and culturally diverse samples.

This Special Issue will foreground innovative empirical work, methodological approaches, and theoretical frameworks that address this gap. We aim to showcase multi-disciplinary contributions that bridge the toddler data desert, fostering new collaborations that will accelerate progress in understanding early childhood development.

This Special Issue welcomes submissions that address, but are not limited to, the following themes:

• Methodological Innovation for Toddlers:
• Adapting and validating neuroimaging (e.g., fNIRS, EEG, eye-tracking), behavioral, or computational methods for use with toddlers.
• Innovations in mobile, home-based, or naturalistic data collection.
• Open science tools and datasets for this age group.
• Theoretical Advances and Developmental Models:
• New frameworks for understanding rapid developmental transitions between infancy and preschool.
• Models integrating across multiple levels (neural, cognitive, behavioral, social).
• Theoretical work that accounts for variability and non-linear change in toddlerhood.
• Diversity and Inclusion:
• Studies including diverse populations (e.g., linguistic, cultural, socioeconomic, neurodiverse), addressing the overrepresentation of WEIRD (Western, Educated, Industrialized, Rich, Democratic) samples.
• Community-engaged research approaches and culturally responsive methods.
• Mechanisms of Developmental Change:
• Longitudinal or experimental work examining mechanisms in language, executive functions, social learning, or emotion regulation.
• Work linking early developmental mechanisms to later outcomes, including risk and resilience trajectories.

Potential Article Types:

• Empirical papers using innovative methods or data sources.
• Theoretical or conceptual reviews proposing new models for toddler development.
• Methodological papers focused on adapting or validating tools for this age group.
• Data resource or open methods papers.
• Brief reports highlighting novel paradigms or pilot data.

Dr. Anastasia Kerr-German
Guest Editor

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Behavioral Sciences is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• neurodevelopment
• cognition
• toddlers
• executive functions
• emotion regulation
• language development