ARTICLE Beyond the conservative hypothesis: a meta-analysis of lexical-semantic processing in Williams syndrome* Carlos Romero-Rivas 1 , Sara Rodríguez-Cuadrado 1 , Lucía Sabater 2 , Pablo Rodríguez Gómez 3 , Irene Hidalgo de la Guía 4 , Eva M. Moreno 5,6 and Elena Garayzábal Heinze 7 1 Department of Developmental and Educational Psychology, Universidad Autónoma de Madrid, Madrid, Spain; 2 Universidad Internacional de La Rioja, Logroño, Spain; 3 Department of Psychology, Universidad Rey Juan Carlos, Madrid, Spain; 4 Department of Spanish and Literature Theory, Universidad Complutense de Madrid, Madrid, Spain; 5 Department of Developmental and Educational Psychology, Universidad Nacional de Educación a Distancia, Madrid, Spain; 6 Faculty of Languages and Education, Universidad Antonio de Nebrija, Madrid, Spain; 7 Department of General Linguistics, Universidad Autónoma de Madrid, Madrid, Spain Corresponding author: Carlos Romero-Rivas; Email: carlos.romeror@uam.es (Received 15 September 2022; Revised 21 April 2023; Accepted 23 April 2023) Abstract Williams syndrome (WS) is a rare genetic disorder, characterised at the cognitive level by a phenotypic pattern of relative weaknesses (e.g., visuospatial skills) and strengths (e.g., some linguistic and nonverbal reasoning skills). In this study, we performed a systematic search and meta-analysis on lexical-semantic processing in WS, an area of knowledge in which contradictory results have been obtained. We found 42 studies matching our criteria, and, in total, 78 effect sizes were included in the meta-analysis. Results showed that individuals with WS have worse lexical-semantic skills than individuals with typical development, whether matched by chronological or mental age. However, people with WS have better lexical- semantic skills than people diagnosed with other cognitive disabilities. Finally, vocabulary skills seem to be relatively spared in WS, although they present some difficulties in semantic processing/integration, semantic memory organisation and verbal working memory skills. Taken together, these results support a neuroconstructivist approach, according to which the cognitive mechanisms involved in lexical-semantic processing may be modulated, even when performance in some tasks (i.e., vocabulary tasks) might be optimal. Keywords: Williamssyndrome;lexical-semantic processing; meta-analysis; neuroconstructivism; modularity 1. Introduction Williams syndrome (WS; also known as Williams–Beuren syndrome) is a rare genetic disorder that occurs in approximately 1:7,500 births (Strømme et al., 2002). It is caused © The Author(s), 2023. Published by Cambridge University Press. *This article was originally published with errors in the affiliations of two authors. The article has been updated and an erratum published at https://doi.org/10.1017/langcog.2023.33. Language and Cognition (2023), 15: 3, 526–550 doi:10.1017/langcog.2023.15 https://doi.org/10.1017/langcog.2023.15 Published online by Cambridge University Press