A remarkable amount of perceptual development occurs in the first year after birth. In this article, we spotlight the case of color perception. We outline how within just 6 months, infants go from very limited detection of color as newborns to a more sophisticated perception of color that enables them to make sense of objects and the world around…

Age-classes are a salient feature of modern schooling. Yet how did age-grouping come to prevail in entire school systems? And how was this form of grouping related to educational and pedagogic discussions at the time of its emergence? The article addresses these issues by looking at the historical context within which age classes came to a…

This text comments on the Keynote article 'Microvariation in multilingual situations: The importance of property-by-property acquisition' by Marit Westergaard, who argues for Full Transfer Potential within the Linguistic Proximity Model in third language (L3) acquisition. The commentary points at some theoretical and methodological issues related…

In response to the articles in this forum, the authors write that they were struck by the way most of the authors assumed that generations are stable entities characterized by readily identifiable factors, such as age, attitudes or circumstances. Following a constitutive philosophy of communication and instruction (Fassett & Warren, 2007;…

This study examined changes in the administrative prevalence of autism spectrum disorders (ASD) in Utah children from 2002 to 2008 by record source (school and health), age (four, six, and eight), and special education classification. Prevalence increased 100% with 1 in 77 children aged eight identified with ASD by 2008. Across study years and age…

Purpose: Preschool children often have difficulties in word classification, despite good speech perception and production. Some researchers suggest that they represent words using phonetic features rather than phonemes. In this study, the authors examined whether there is a progression from feature-based to phoneme-based processing across age…

This study is the first to examine adolescent cigarette report stability over 10 years. Six waves of data were utilized from the National Longitudinal Survey of Youth. This study examined internal/logical consistency and external consistency. Report stability was higher for lifetime use reports than the age of onset reports. Wave-by-wave…

Assessment of children's restricted and repetitive behaviours offers potential opportunities to improve early diagnosis of autism spectrum disorder (ASD) and timely access to interventions and support. To facilitate this requires understanding of the phenomenology of repetitive behaviours in ASD, including differentiating behaviours seen in ASD…

The ability to infer the referential intentions of speakers is a crucial part of learning a language. Previous research has uncovered various contextual and social cues that children may use to do this. Here we provide the first evidence that children also use speech disfluencies to infer speaker intention. Disfluencies (e.g. filled pauses "uh"…

The authors examined parent-child interactions among three groups: selectively mute, anxious, and non-anxious children in different contexts. The relation between parental control (granting autonomy and high power remarks), child factors (i.e., age, anxiety, verbal participation), and parent anxiety was investigated. Parental control varied by…

The authors investigated the ability of 9- to 11-year-olds and of adults to use similarity-based and rule-based processes as a function of task characteristics in a task that can be considered either a categorization task or a multiple-cue judgment task, depending on the nature of the criterion (binary vs. continuous). Both children and adults…

How does understanding the decimal system change with age and experience? Second, third, sixth graders, and adults (Experiment 1: N = 96, mean ages = 7.9, 9.23, 12.06, and 19.96 years, respectively) made number line estimates across 3 scales (0-1,000, 0-10,000, and 0-100,000). Generation of linear estimates increased with age but decreased with…

In two experiments, one hundred ninety-two 3-year-olds, 4-year-olds, and adults heard a novel word for a target object and then were asked to extend the label to one of two test objects, one matching in shape-based object category (the shape match) and the other matching in a property other than shape (the property match). We independently…

Given that this special issue is devoted to the acquisition and processing of inflectional morphology by second language (L2) learners, the question in the title may appear redundant. However, recent research on first language (L1) and L2 morphological processing has challenged basic assumptions about the status of inflectional morphology in…

Base rate information is important in clinical assessment because one cannot know how unusual or typical a phenomenon is without first knowing its base rate in the population. This study empirically determined the base rates of social skills acquisition and performance deficits, social skills strengths, and problem behaviors using a nationally…