People
Principal Investigator

Fei Xu​
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Professor
My research focuses on cognitive and language development, from infancy to early childhood. For the last decade, my collaborators, students, and I have advocated for a new approach to cognitive development, namely rational constructivism. We have argued that human infants begin life with a set of proto-conceptual primitives such as object, number, and agent, and as young learners acquire language, these initial representations are transformed into a format that is compatible with language and propositional thought. We have suggested that three types of learning mechanisms explain both belief revision and genuine conceptual change: (1) Language and symbol learning; (2) Bayesian inductive learning; and (3) Constructive thinking. Lastly, we have argued that infants and children are active learners, and cognitive agency is part and parcel of development. For some representative publications on this view, see Xu (2019, Psychological Review), Fedyk and Xu (2018, Review of Philosophy and Psychology), Luchkina and Xu (2022, Psychological Review), Denison and Xu (2019, Perspectives on Psychological Science), Xu and Kushnir (2013, Current Directions in Psychological Science), and Xu and Kushnir (2012, Rational Constructivism in Cognitive Development – an edited volume).
Gabriella Morales​​
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Project Manager
gabriella.morales@berkeley.edu
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Gabriella is the project manager for the Tsimane' project, investigating mathematical cognition and probability reasoning in the U.S. and Bolivia. This is a joint project between the Piantadosi Lab and the Xu Lab. Before joining the BELLab, Gabriella received a B.A. in Psychology from Colorado College.
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Project Manager

Postdoctoral Fellows

Graduate Students

Stephanie Alderete​​
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Graduate Student
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How do humans process information about the world in order to make informed and rational decisions? I investigate the developmental origins of decision-making by studying how infants and young children make decisions and reason about the world around them. Currently, I am studying children’s ability to do probabilistic and logical reasoning.


Alyson Wong​
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Graduate Student
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I am broadly interested in infants' and children's conceptual development and probabilistic reasoning abilities. I am currently interested in how infants and children use probabilistic information to make decisions and reason about the world around them. I am also interested in the development of compositionality and the role of language in conceptual development.
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Cristina Sarmiento​​
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Graduate Student
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I am broadly interested in how children use language and social interactions to learn about objects and the social world. Before joining the BELL lab, I received a B.A. in psychology from UCLA and was the lab manager for Dr. Elizabeth Spelke's lab for developmental studies at Harvard University.
Hailey Lambert​​
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Graduate Student
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My research interests focus on how children play an active role in their own linguistic and cognitive development. I am also interested in research involving marginalized communities, particularly disabled populations and members of Indigenous Nations. This interest is informed by my identity as an enrolled citizen of the Choctaw Nation of Oklahoma and a registered first-generation descendant of the Eastern Band of Cherokee Indians.
