Infant Behavior & Development 33 (2010) 309–313 Contents lists available at ScienceDirect Infant Behavior and Development Individual differences in children’s production of scale errors Karl S. Rosengren a,* , Stevie S. Schein b , Isabel T. Gutiérrez a a Department of Psychology, Northwestern University, 2029 Sheridan Road, Evanston, IL 60208, United States b Department of Psychology, University of Illinois, United States article info Article history: Received 21 October 2009 Received in revised form 8 March 2010 Accepted 19 March 2010 Keywords: Scale errors Child cognitive development abstract Individual differences in the production and persistence of committing scale errors were examined in children (age range 18–29 months) attending a laboratory preschool. Minia- ture replica toys were placed in the classrooms during three 20-min observation periods for 10 weeks. The majority of the children (88%, n = 24) performed scale errors providing confir- mation in a different setting (than presented in previous research) that most young children commit these behaviors. Large individual differences were found in the frequency and per- sistence of committing scale errors. Extended exposure to the replica items increased the number of scale errors, though the frequency of scale errors decreased over the entire observation period. © 2010 Elsevier Inc. All rights reserved. Young children sometimes attempt to perform actions, such as sitting on a tiny chair, which the object, due to its small size, cannot accommodate. Initial anecdotal reports of these behaviors, labeled as scale errors (DeLoache, Uttal, & Rosengren, 2004), have been confirmed by studies performed in the laboratory (Brownell, Zerwas, & Ramani, 2007; DeLoache et al., 2004; Ware, Utal, Wetter, & DeLoache, 2006), using parental diary methods (Rosengren, Gutiérrez, Anderson, & Schein, 2009b), an Internet survey (Ware, Utal, & DeLoache, 2010), and natural observation in preschool classrooms (Rosengren, Carmichael, Schein, Anderson, & Gutiérrez, 2009a). Each of these past studies reported variation across children in the frequency of scale errors, though none of these reports explicitly examined individual differences in this behavior. The aim of the present research was to more closely examine individual differences in the production of scale errors and to study the influence of repeated exposure to objects that elicit these behaviors. Laboratory assessments of scale errors have generally involved a single session where children are exposed to miniature scale replicas of appropriately scaled chairs, slides, and toy cars (Brownell et al., 2007; DeLoache et al., 2004). In DeLoache et al. (2004), approximately half (46%; 25/54) of the 18–30-month-old children tested performed at least one scale error in the laboratory with some committing as many as four scale errors in 20 min. Their focus was on body scale errors (Rosengren et al., 2009a) where a child attempts to fit their own body on or in an object that is too small for them to fit on or in. Ware et al. (2006) found a slightly higher percentage of scale errors in their study of scale errors involving dolls and other objects (62%; 46/74) with older children (35–40 months of age) committing more errors than younger children (16–24 months of age). Although these authors did not report the range of scale errors, children in this study performed an average of 1.4 of these behaviors. These behaviors involving two objects have been labeled as object scale errors (Rosengren et al., 2009a). A number of investigators have shown that scale errors occur in the everyday lives of children. For example, using a 6- month diary approach Rosengren et al. (2009b) found that 29 of 30 parents reported that their children (aged 13–21 months initially) committed at least one scale error. Children in this study committed between 0 and 8 scale errors over the course * Corresponding author. Tel.: +1 847 467 3880. E-mail address: k-rosengren@northwestern.edu (K.S. Rosengren). 0163-6383/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.infbeh.2010.03.011