The articles in this special issue of the "Journal of Cognition and Development" examine the cognitive development of children who are following typical and atypical developmental pathways. The articles offer a mixture of theory-based considerations, reviews of the literature, and new empirical data addressing fundamental aspects of…

Most people have 23 pairs of chromosomes; one set from the mother and one from the father. However, nondisjunction errors during meiosis can lead to a case of trisomy, where there are three rather than two chromosomes. Although such events are not uncommon, they are usually lethal, and account for a high proportion of spontaneous abortions. There…

J. E. Grusec and M. Davidov's article (this issue) about domains of parenting and their links with different aspects of childhood outcome raises both interesting questions and challenges. Four of these concerns are discussed in relation to early childhood. First is the issue of bidirectionality. Recent studies highlight the contribution of…

One of the popular misconceptions about giftedness is that the gifted label is a benefit. It is probably a fixed blessing at best and can bring unexpected problems to children, their families, and their teachers. Children who are labeled gifted often have uncertain feelings about the designation and the whole "gifted" experience, if not…

Developmental exceptionalities span the range of learning abilities and encompass children with both learning disorders and learning gifts. The purpose of this article is to stimulate thinking about these exceptionalities, particularly the complexities and variations within and across people. Investigators tend to view learning disabilities or…

In an intriguing account, the hypothesis is proposed that elevating effects of quantity of childcare on aggression might not, as other research has suggested, be dissipating over time, but instead be diffusing across groups of children. Paradoxically, this diffusion may also affect children with little or no experience with non-maternal care. If…

Provides an introduction to a special section on developmental behavioral genetics (the study of genetic and environmental influences on individual differences in behavioral development), discussing the potentialities of the interdiscipline and presenting an overview of the following articles. (Author/RH)

Argues that developmental significance of friendships cannot be examined without distinguishing between the concepts of having friends, the identity of the child's friends, and friendship quality. Concludes that the identity of the child's friends and friendship quality may be more closely tied to developmental outcomes than merely whether the…

A research study of identical twins, by Thomas J. Bouchard Jr., discloses that genetics exert a stronger influence over personality than we thought. Parents and teachers are advised to be active and alert observers of children's interests and talents to provide appropriate tools and resources to develop these propensities. (MLF)

School readiness encompasses two different terms in Estonia: school maturity and school readiness. School maturity involves stages in growth a child experiences up to a certain level of development. School readiness involves that point in development at which a child is ready to enter school. Because children develop at different rates, ways…

Suggests ways to use dynamic systems analysis to illuminate the pluralistic and multidimensional model described by Larivee, Normandeau, and Parent (2000). Issues discussed include the characteristics of developmental transitions, such as hysteresis; nature of growth processes, such as hierarchical development or predator-prey interactions; and…

Considers areas of consensus from commentaries, including the value of an evolutionary perspective and the utility of exploring variations in physical activity play. Examines areas of debate, including the nonplay-play distinction, functions of rough-and-tumble play, and the opportunities of juveniles for exercise training. Calls for more directed…

This paper addresses the unevenness of the existing knowledge base on development and individual differences, and presents a structural model diagraming organismic and environmental influences on development. The model identifies sets of conditions which can result in gifted performance, the development of giftedness, and the maintenance of…

Examines research on the importance of understanding children's biological timetables for mind and brain development, and forces that can threaten this neurodevelopmental timetable during critical periods. Discusses the brain's adaptability, and focuses on the importance of knowledge derived from the study of special populations for understanding…

The concept of psychosocial stress is reviewed in relation to empirical findings on the effects of different types of life events in childhood and adult life. It is concluded that the concept is too broad and that the events need to be subdivided according to their characteristics and meaning. (Author/DB)