Parental criticism and warmth toward unrecognized monozygotic twins

The Interplay Between Genotypes and Family Relationships

Children's genotypes and their social relationships are correlated throughout their development. Heritable characteristics of children evoke strong and specific responses from their parents; frequently, these same heritable characteristics also influence the children's adjustment. Moreover, parental heritable traits that influence their parenting are also transmitted to children and influence their children's adjustment. Thus, genetically influenced evocative processes from children and parental-transmission mechanisms influence the covariances between measures of family relationships and child development. These findings suggest new targets for preventing adverse development: altering parental responses to heritable characteristics of children and influencing the genetically influenced ontogeny of parenting.

Twin Studies of Multiple Myeloma / Research Reviews and News: Critique of Twin Research; Opposite-Sex Twins and Sexual Attraction; Twinning Rates and Assisted Reproductive Technology; Family History of Multiple Implantation / Human Interest: Book Party: Born Together — Reared Apart; Morning Sickness and Twins; Sexuality in Conjoined Twins; Kofi Annan: Opposite-Sex Twin; Switched at Birth

A foundation for studying multiple myeloma, launched by a monozygotic twin, is described. Twin studies of that disease are also examined. A summary of selected research studies and news events follows, with specific reference to a new critique of twin research, sexual attraction in separated opposite-sex twins, twinning rates following assisted reproductive technology and family histories of multiple implantation. Human interest topics cover a gathering of researchers from the Minnesota Study of Twins Reared Apart, morning sickness and twin pregnancy, sexuality in conjoined twins, a famous hidden twin, and a film about switched at birth babies.

Genetic influences on anxiety in children: what we've learned and where we're heading

Anxiety is a common problem, typically beginning early in life. This article explores reasons for individual differences in levels of anxiety among children, by reviewing the genetic literature. The plethora of research to date has demonstrated clearly that both genes and environmental influences play important roles in explaining differences in levels of anxiety of various types among children. This has encouraged researchers to search for specific genes and environmental influences upon anxiety. Despite important progress in identifying links between anxiety and specific genes--including associations between serotonin and dopamine genes and different symptoms of anxiety--overall, progress has been slow because multiple genes of small effect size are likely to influence anxiety. This article explains how the hunt for genes involved in anxiety is likely to benefit from genetically sensitive research, which examines the co-occurrence of symptoms; includes measures of the environment; and examines endophenotypes and risk pathways.

Genetics and children's experiences in the family

Genetic research may have its greatest impact for clinicians and developmental researchers in terms of understanding the environment and how the environment relates to children's development. This review focuses on one example at the interface between nature and nurture. Recent research using diverse genetic designs shows that family environment as it is currently assessed involves a substantial contribution from genetic factors. Genetic factors also contribute to correlations between measures of the family environment and developmental outcomes. Implications of these findings are discussed.

A comparison of twins and singletons with child psychiatric disorders: an Item Sheet study

An important assumption underlying the twin method of comparing MZ and DZ twins is that results from twin samples can be generalized to the larger singleton population. This study uses Item Sheet data on child psychiatric patients to compare twins and singletons on demographic, diagnostic and symptomatic variables. Although little difference was found between the two groups, conduct disorders were significantly over-represented in the twin population. The significance of this finding is discussed. This study lends overall support for the use of the twin method in child psychiatric samples.