Many autistic people and people with non-spectrum neurodevelopmental disabilities (e.g. intellectual disability) report feeling lonely, which can negatively impact their well-being. There is little longitudinal research, however, tracking changes in how autistic people experience, conceptualize, and cope with loneliness throughout their lives. A…

Previous research suggested that adolescents with autism spectrum disorder are better than typically developing children in detecting local, non-social details within complex visual scenes. To better understand these differences, we used the image database by Sareen et al., containing the size and on-screen location information of all changes in…

Identifying change at the individual level is an important goal for researchers, educators, and clinicians. We present a set of statistical procedures for identifying individuals who depart from a normative change. Using Latent Change Scores models (LCS), we illustrate how the Individual Likelihood computed from a statistical model for change…

Research on secular trends in mean intelligence test scores shows smaller gains in vocabulary skills than in nonverbal reasoning. One possible explanation is that vocabulary test items become outdated faster compared to nonverbal tasks. The history of the usage frequency of the words on five popular vocabulary tests, the GSS Wordsum, Wechsler…

Despite Kaufman, Raven's Progressive Matrices and the Wechsler subtest Similarities are tests whose gains call for special explanation. The spread of "scientific spectacles" is the key, but its explanatory potential has been exhausted. Three trends force us to look elsewhere: (a) gains on Wechsler subtests such as Picture Arrangement,…

The Flynn effect, a secular rise in IQ seen throughout the world, was examined on the WISC-R and WISC-III subtests in a longitudinal sample of more than 2,500 school children who were tested between 1974 and 2002. Multivariate analysis of variance and multiple regression analyses revealed that all the subtests experienced significant decreases in…

While the magnitude of the Flynn effect is well established (approximately 3 points a decade on the Wechsler scales), the causes behind it are still unknown and hotly debated. Kaufman argues that, because of the administrative and scoring changes that occurred with the introduction of the Wechsler Intelligence Scale for Children-Revised, Flynn's…

Flynn wrote a book devoted to the Flynn effect, featuring his theoretical explanation of why the intelligence of worldwide populations has apparently increased from generation to generation. The essence of his theorizing is that because of the societal impact of scientific technology, people of today are much more guided by abstract, rather than…

This study investigated the Wechsler Performance IQ (PIQ) or Perceptual Reasoning Index (PRI)/ Perceptual Organization Index (POI) change over time and its relation to ability levels. PIQ or PRI/ POI was analyzed because of the known sensitivity of nonverbal scales to the Flynn effect. Scores were analyzed using two methods. First, analysis of…