Jill G. de Villiers (born 1948) is a developmental psychologist known for her work in the field of language acquisition.^[1] She is the Sophia and Austin Smith Professor Emerita of Psychology and Philosophy at Smith College.^[2] de Villiers is a Fellow of the American Psychological Association. In 2018, she was elected as a Member of American Academy of Arts and Sciences.^[1]

de Villiers and her colleagues have developed critical tools for language assessment including the Quick Interactive Language Screener (QUILS),^[3] which is a computerized preschool language assessment, and the Diagnostic Evaluation of Language Variation (DELV), which aims to provide assessment for speakers of English dialects such as African-American English.^[4][5]

de Villiers completed her B.S. degree in psychology from the University of Reading in 1969.^[2] She attended graduate school at Harvard University where she obtained her Ph.D in experimental psychology at 1974 under the supervision of Roger Brown.^[6] After graduating, she taught at Harvard University for 8 years before moving to Smith College in 1971. At Smith, she received the Honored Professor award in 2003 and the Faculty Teaching award in 2002.^[2]

de Villiers work focuses on language acquisition, with a specific focus on young children's ability to use words and sentences to communicate with others. Her many contributions include studies of language acquisition in oral deaf children^[7] and relationships between language development and theory of mind.^[8][9] de Villiers' research has been funded by the March of Dimes,^[10] National Science Foundation,^[11] the Institute of Education Sciences,^[12] and the National Institute on Deafness and Other Communication Disorders.^[13]

• de Villiers, J. G., & de Villiers, P. A. (1978). Language acquisitions . Harvard University Press.
• de Villiers, J., & Roeper, T. (Eds.). (2011). Handbook of generative approaches to language acquisition. Springer Science & Business Media.

• de Villiers, J. G. (2007). The interface of language and theory of mind. Lingua , 117 (11), 1858–1878.
• de Villiers, J. G., & de Villiers, P. A. (1973). A cross-sectional study of the acquisition of grammatical morphemes in child speech. Journal of Psycholinguistic Research, 2(3), 267–278.
• de Villiers, J. G., & de Villiers, P. A. (1973). Development of the use of word order in comprehension. Journal of Psycholinguistic Research, 2(4), 331–341.
• de Villiers, J. G., Flusberg, H. B. T., Hakuta, K., & Cohen, M. (1979). Children's comprehension of relative clauses. Journal of Psycholinguistic Research, 8(5), 499–518.
• de Villiers, J. G., & Pyers, J. E. (2002). Complements to cognition: A longitudinal study of the relationship between complex syntax and false-belief-understanding. Cognitive Development , 17 (1), 1037–1060.