Attempts to show how genes and environments cooperate in the construction of organisms, focusing on how genes require environmental and behavioral inputs to function appropriately during the normal course of human development. The discussion is related to a model of probabilistic epigenesis. (SLD)

This paper examines the validity of Asperger syndrome as a condition apart from high-functioning autism. Potential differences between Asperger syndrome and autism is possible if both are strictly defined. The importance of genetic factors in Asperger syndrome is stressed. Research on the nosological validity of this condition and its relationship…

The biometrical school of scientists who fit models to IQ data traces their intellectual ancestry to R. Fisher (1918), but their genetic models have no predictive value. Fisher himself was critical of the concept of heritability, because assortative mating, such as for IQ, introduces complexities into the study of a genetic trait. (SLD)

Discusses a model that describes how knowledge is obtained in environmental microbiology. Suggests that constraints on knowledge will yield to relationships between methodological innovations and their iterative application. Contains 132 references. (DDR)

Points out the difficulties students have in making connections from the DNA molecule to a phenotype. Presents an activity in which students imitate the actions of functional and nonfunctional enzymes and examine the phenotype of organisms of different genotypes. (YDS)

Examines the empirical evidence cited in favor of the operation of genetic factors in attention-deficit hyperactivity disorder and argues that the evidence does not support a role for genetic factors in the disorder. Discusses problems compromising family, twin, and adoption studies. (JPB)

Describes an approach that provides mathematical tips and helpful suggestions for presenting the Hardy-Weinberg equilibrium to predict allele frequencies, phenotypes, and genotypes in populations. (ASK)

This article presents a case report of a male child with Fragile X syndrome, typical autistic behavior, and cerebellar hypoplasia. Questions are raised concerning the possible role and importance of cerebellar abnormalities in relation to autistic symptoms. (DB)

Reports a study that investigated knowledge level about sickle cell disease among students at a predominantly black university. Survey results indicated the students most directly concerned did not well understand the basic facts about sickle cell disease. Most students could not recall whether they had ever been tested. (SM)

This article notes a current de-emphasis on genetic syndromes in published articles concerning mental retardation despite major deoxyribonucleic acid (DNA) advances in determining mental retardation causes. The article calls for incorporation of these genetic advances into behavioral research of mental retardation, especially as reflected in the…

Presents an exercise that demonstrates the chromosome-gene-protein connection using sickle-cell anemia, a genetic disease with a well-characterized molecular basis. Involves connecting changes in DNA to protein outcomes and tying them into the next generation by meiosis and gamete formation with genetic crosses. Motivates students to integrate…

Introduces a special section of five articles that highlight new collaborative research opportunities for developmental psychologists and other biomedical researchers. Such research has focused on the transition from fetus to newborn, evaluation of early toxin exposure, and the behavioral phenotype associated with genetic syndromes. (MDM)

Discusses the Human Genome Project and the identification of Fragile X Syndrome, the most common inherited cause of mental retardation. Fragile X Syndrome is caused by an abnormal gene on the bottom of the X chromosome. Examined the phenotype of Fragile X Syndrome in males and females and the spectrum of learning difficulties caused by the…

Provides laboratory exercises that demonstrate two genetic concepts: the difference between a genetic selection and a genetic screening experiment, and the relationship between phenotype and genotype. (SAH)

Discussion of Williams syndrome, a genetic disorder with a variety of medical and developmental features, focuses on frequent outward expression of happiness. Analysis of the unique expression of happiness in individuals with Williams syndrome is followed by discussion of this happiness in the context of other dimensions of the syndrome,…