Prader-Willi syndrome (PWS) is characterized by temper tantrums, impulsivity, mood fluctuations, difficulty with change in routine, skinpicking, stubbornness and aggression. Many studies on behavior in PWS are limited by sample size, age range, a lack of genetically confirmed diagnosis of PWS and inconsistent assessment of behavior. The aim of…

The focus of this study was the developmental pattern of the ability to shift attention between global and local levels of hierarchical stimuli. Children aged 7 years and 11 years and 21-year-old adults were administered a task (two experiments) that allowed for the examination of 1) the direction of attention to global or local stimulus levels;…

Fifty-six Dutch school children (aged 6-0 to 14-4 years) participated in a study designed to investigate their ability to reason with logical implication. They answered a total of 32 reasoning problems. Before or after each question they were asked a class inclusion question. A high degree of correspondence was found between class inclusion and…

Using multiple dimensions of solidarity and conflict in a latent class analysis, we develop a typology of adult child-parent relationships. The data (N = 4,990) are from the first wave of the Netherlands Kinship Panel Study. In descending order of relationship quality, the 5 types are harmonious (akin to relationships with friends), ambivalent…

Compared 28- to 53-month-olds' writing and drawing. Scores on a writing scale composed of graphic, "writing-like," and symbolic schemes improved with age. Recognition of drawings as drawings preceded recognition of writings as writings. Writing and drawing scores were substantially correlated, even with age partialed out, suggesting that…