Considerable research has demonstrated that English-speaking children extend nouns on the basis of shape. Here we asked whether the development of this bias is influenced by the structure of a child's primary language. We tested English- and Spanish-speaking children between the ages of 1 ; 10 and 3 ; 4 in a novel noun generalization task. Results showed that English learners demonstrated a robust shape-bias, whereas Spanish learners did not. Further, English-speaking children produced more shape-based nouns outside the laboratory than Spanish-speaking children, despite similar productive vocabulary sizes. We interpret the results as evidence that attentional biases arise from the specifics of the language environment. (Contains 1 footnote.)