Objective age of acquisition for 223 Italian words: norms and effects on picture naming speed

The present study provides a set of objective age of acquisition (AoA) norms for 223 Italian words that may be useful for conducting cross-linguistic studies or experiments on Italian language processing. The data were collected by presenting children from the ages of 2 to 11 with a normed picture set (Lotto, Dell'Acqua, & Job, 2001). Following the study of Morrison, Chappell, and Ellis (1997), we report two measures of objective AoA. Both measures strongly correlated with each other, and they also showed a good correlation with the rated AoA provided by adult participants. Furthermore, we assessed the relationship between the AoA measures and other variables used in psycholinguistic experiments. Regression analyses showed that familiarity, typicality, and word frequency were significant predictors of AoA. AoA, but not word frequency, was found to determine naming latencies. Finally, we present a path model in which AoA is a mediator in predicting speed in picture naming. The norms and the picture set can also be downloaded from http://dpss.psy.unipd.it/files/strumenti.php and from http://brm.psychonomic-journals.org/content/supplemental.