The prevalence of autism/autism spectrum disorder (ASD) has been increasing across the world. Previous studies in Norway reported, that the prevalence rate for 0-10-year-old children is 1 in 166, and in the case of 11-year-old children it is 1 in 125. Moreover, another nationwide study discovered that 1 in 192 males and 1 in 695 females between…

An innovation in developing the Supports Intensity Scale--Children's Version (SIS-C) was the adoption of latent variable modeling approaches to norm development. In regard to translated versions of the SIS-C, the latent modeling approaches provided opportunities to leverage the large standardization sample generated in the United States (n=4,015)…

We address how to conceptualize and measure intentional self-regulation (ISR) among adolescents from four cultures by assessing whether ISR (conceptualized by the SOC model of Selection, Optimization, and Compensation) is represented by three factors (as with adult samples) or as one "adolescence-specific" factor. A total of 4,057 14-…

This study reports findings on Internet gambling and problem gambling among Icelandic youth. Participants were 1.537 13-18 year-old students, 786 boys and 747 girls. Results revealed that 56.6% had gambled at least once in the past 12 months and 24.3% on the Internet. Gender and developmental differences were found for Internet gambling, as boys…

In this paper, we estimate the effect of pupil's relative age within the first grade of primary school on mathematics and reading test scores at age 15. The main objective is to evaluate the long-term causal effect of relative age in the first grades of primary school on pupil's test in 16 different countries. We use the national rule for…

Objective: To develop a child victimization survey among a diverse group of child protection experts and examine the performance of the instrument through a set of international pilot studies. Methods: The initial draft of the instrument was developed after input from scientists and practitioners representing 40 countries. Volunteers from the…

This longitudinal study examined effects of family socialization on sociomoral reasoning in the context of the peer and parent-child relationships. Subjects were 121 urban Icelandic children. Social class was constructed as a multinominal measure defined by the nature of work, education, authority, and responsibility of the parents in the work…

This longitudinal study examined the multiple influences of social class and family socialization on intelligence at age 7, and on the development of cognitive competence from age 7 through age 15 in a sample of 121 urban Icelandic children and adolescents. Socialization condition was defined as sources of parental support and control strategies,…