This study provides support for a potential subclinical marker in the executive function domain of siblings (n=18, ages 8-18) of autistic individuals, compared to learning-disabled controls. No group differences in theory-of-mind abilities were found. The need to develop more sensitive measures is discussed. (Author/JDD)

A large body of data is reviewed to support a new theory of motion perception described by S. Grossberg and M. E. Rudd (1989). The Motion Boundary Contour System is used to explain classical and recent data about motion perception that have not been explained by other models. (SLD)

Current research increasingly points to the importance of biological factors in the etiology of psychotic disorders and the concomitant need for a shift in treatment modalities. A scale to assess the extent to which practitioners have made this shift was developed and validated. Results from two surveys are reported. (Author/EMK)

To study whether individual differences in general cognitive ability differ in males and females, full-scale IQ data from 426 child twin pairs were fitted to a structural equation model of sex limitation. Individual differences in general cognitive ability appear to be substantially due to common genetic influences in males and females. (SLD)

Describes the IQ Quantitative Trait Loci (QTL) project, an attempt to identify genes underlying IQ score variations using maps from the Human Genome Project. The essay argues against funding the IQ QTL project because it will end the debates about the genetic basis of intelligence and may lead directly to eugenic programs of genetic testing. (SLD)

Argues that there is a wealth of little known but rapidly growing evidence that contradicts the assumptions and claims of genetic determinism. Recent research showing the impacts of child maltreatment and environmental pollutants suggest interventions that might alleviate the problems sometimes attributed to genetic deficiencies. (SLD)

Considers biodiversity a controversial issue in the education of students 11-18 years of age in schools, particularly as it relates to science education. Features a study of teachers' attitudes and approaches to biodiversity in the United Kingdom which was undertaken using participatory appraisal methods with focus groups of teachers. (Author/SAH)

Examines the biological factors underlying autism, focusing on research in four areas: (1) neurological abnormalities; (2) biochemical abnormalities; (3) genetic problems; and (4) problems during pregnancy or birth. Maintains that autism is a heterogeneous disorder and that there is no unified model that explains its etiology. (Author/KB)

Replies to Beatty and McCroskey's response to this author's response and challenges to their articles in this issue and elsewhere on communibiology. Explains why taking biology seriously in human communication does not entail either the belief that biology is genetically determined or that human biological systems are immutable. (SR)

Used steady-state probe topography to investigate the cortical activity of 12 average and 12 high IQ Australian college students during a spatial working memory task. Results, in terms of changes in visual evoked potentials, suggest that the areas of the brain involved in working memory are influenced by individual differences in intelligence.…

This study investigated fluctuations in anxiety and menstrual distress across the menstrual cycle. Female college students (N = 318) completed self-report measures of symptoms across the menstrual cycle and measures of general psychological adjustment. A subgroup (n = 56) of Anxious participants who reported high levels of anxiety was identified.…

This chapter discusses biological contributions to adolescent female sexual development and, based on a developmental systems framework, suggests future research directions.

It has been clearly established that there is an increased incidence of early onset dementia of the Alzheimer type (DAT) in people who have Down syndrome. There are variations in the age of onset of the clinical signs of DAT, which may be accounted for by different risk factors. In this review we examined the evidence that different biological and…

Lev Vygotsky argues that natural properties as well as social relations, constrain--and therefore make possible--the social construction of a child's higher psychological processes. Most social constructivists in the cultural-historical tradition focus on three Vygotskian tenets: (1) the internalization of auxiliary cultural means or signs…

This book provides the basic knowledge and guides for the construction and operation of a small-scale, family-size biogas unit. The first chapter discusses the benefits of biogas production and the Chinese biogas model. The second chapter shows the components, design formulas, and sizing units of the biogas model. Chapter 3 describes actual…