Semicircular canal size constrains vestibular function in miniaturized frogs.

Miniaturization has evolved repeatedly in frogs in the moist leaf litter environments of rainforests worldwide. Miniaturized frogs are among the world's smallest vertebrates and exhibit an array of enigmatic features. One area where miniaturization has predictable consequences is the vestibular system, which acts as a gyroscope, providing sensory information about movement and orientation.

Current parental depression and offspring perceived self-competence: a quasi-experimental examination.

A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52 %) and female offspring aged 15.7 ± 2.

Higher-order genetic and environmental structure of prevalent forms of child and adolescent psychopathology.

Context: It is necessary to understand the etiologic structure of child and adolescent psychopathology to advance theory and guide future research.

Objective: To test alternative models of the higher-order structure of etiologic effects on 11 dimensions of child and adolescent psychopathology using confirmatory factor analyses of genetic and environmental covariances.

Design: Representative sample of twins.

The etiology of associations between negative emotionality and childhood externalizing disorders.

Despite consistent documentation of associations between childhood negative emotionality and externalizing psychopathology, few genetically informative studies have investigated the etiology of that association. The goal of the current study was to delineate the etiology of the covariation of negative emotionality and childhood externalizing problems (e.g.

Familial confounding of the association between maternal smoking during pregnancy and offspring criminality: a population-based study in Sweden.

Context: The association between maternal smoking during pregnancy (SDP) and offspring disruptive behaviors has been well documented, but it is unclear whether exposure to SDP or the effects of factors correlated with SDP account for the increased risk.

Objective: To test whether the association between SDP and offspring criminal convictions was consistent with a causal connection or due to familial background factors by controlling for measured covariates and using a quasi-experimental approach.

Design: We used a population-based study of children born in Sweden from 1983 to 1989 (N = 609,372) to examine the association between SDP and offspring criminal convictions while controlling for measured traits of both parents.

A quasi-experimental study of maternal smoking during pregnancy and offspring academic achievement.

The current study, based on all births in Sweden from 1983 to 1991 (N = 654,707), explored the processes underlying the association between smoking during pregnancy (SDP) and offspring school grades and mathematic proficiency at age 15. The analyses compared relatives who varied in their exposure to SDP and who varied in their genetic relatedness. Although SDP was statistically associated with academic achievement (AA) when comparing unrelated individuals, the results suggest that SDP does not cause poorer academic performance, as full siblings differentially exposed to SDP did not differ in their academic scores.