Feeling inhibited and socially not at ease is reflected in the trait social inhibition (SI). SI is associated with psychopathology that arises in young adulthood, such as anxiety. We aim for a better insight into the genetic and environmental contributions to SI across the life span, and as such examine their contributions to SI stability and…

Longitudinal data from a large sample of twins participating in the Netherlands Twin Register (n = 42,827, age range 3-16) were analyzed to investigate the genetic and environmental contributions to childhood aggression. Genetic auto-regressive (simplex) models were used to assess whether the same genes are involved or whether new genes come into…

In communities with an increased prevalence of hereditary deafness, social, and linguistic adaptations are found in response. Aulbers (1959) describes a high prevalence of deafness in a fishing village on the Dutch coast: Katwijk aan Zee. This article aims to assess the current prevalence of deafness in Katwijk, as well as the current sign…

Purpose: Behavioral genetic studies of speech fluency have focused on participants who present with clinical stuttering. Knowledge about genetic influences on the development and regulation of normal speech fluency is limited. The primary aims of this study were to identify the heritability of stuttering and high nonfluency and to assess the…

In this study socio-demographic, deafness-related and diagnostic characteristics of hearing impaired children and adolescents referred to a national mental health service for deaf and hard of hearing children and adolescents were examined. Socio-demographic and diagnostic characteristics were compared to corresponding characteristics of hearing…

The relation between intelligence and birth order was shown in a recent publication [Bjerkedal, T., Kristensen, P., Skjeret, G. A. & Brevik, J. I. (2007). Intelligence test scores and birth order among young Norwegian men (conscripts) analyzed within and between families. "Intelligence," 35, 503-514] to be negative. Subjects in this…

In the wake of developments in France and the United States where early psychiatrists such as Pinel, Esquirol, Belhomme and Seguin advocated "moral treatment" of the insane and classified"idiots" and "imbeciles" as incurable though educable, the Revd C. E. Van Koetsveld initiated his "School for Idiots" in…

Although many research studies report students' Lamarckian misconceptions, only a few studies present learning and teaching strategies that focus on the successful development of the concept of natural selection. The learning and teaching strategy for upper secondary students (aged 15-16) presented in this study conducted in The Netherlands is…