Many studies have assessed the costs of sibling rivalry in systems where offspring always have competitors, but conclusions about sibling rivalry in these species are restricted to interpreting the cost of changes in the relative level of competition and are often complicated by the expression of potentially costly rivalry related traits. Additionally, the majority of studies focus on early-lif...

This article investigates the phenomenon of interindividual rivalry and its consequences for motivation and task performance. Two studies of adults from the general population found that rivalry, as compared to nonrival competition, was associated with increased motivation and performance, controlling for tangible stakes, dislike, and other factors. Then, a large-scale archival study of long-di...

Mammal life history traits relating to growth and reproduction are extremely diverse. Sibling rivalry may contribute to selection pressures influencing this diversity, because individuals that are relatively large at birth typically have an advantage in competition for milk. However, selection for increased growth rate is likely to be constrained by kin selection and physiological costs. Here, ...

We introduce forest straight-line programs (FSLPs) as a compressed representation of unranked ordered node-labelled trees. FSLPs are based on the operations of forest algebra and generalize tree straight-line programs. We compare the succinctness of FSLPs with two other compression schemes for unranked trees: top dags and tree straight-line programs of first-child/next sibling encodings. Effici...

Abstract Objective The great majority of patients with childhood leukemia become long-term survivors. They treated with chemotherapy and prophylactic central nervous system (CNS) irradiation. The aim of this cross-sectional study was to evaluate effect of the long-term toxicity in ALL survivors, and possible effects of this treatment on their intellectual in compare with their sibling. Mater...

CONTEXT While parental cardiovascular disease (CVD) doubles the risk for CVD in offspring, the extent of increased risk associated with sibling CVD is unclear. OBJECTIVE To determine, using validated events, whether sibling CVD predicts outcome in middle-aged adults independent of other risk factors. DESIGN, SETTING, AND PARTICIPANTS The Framingham Offspring Study, an inception cohort of th...

The current investigation examined the long-term prediction of sibling jealousy assessed in a laboratory-based paradigm on sibling relationship quality 2 1/2 years later. This multi-method longitudinal study included mothers, fathers, and two children from 35 families. Younger siblings were 16 months and older siblings were, on average, 4 years at Time 1. Positive longitudinal associations were...

Objectives: Sibling relationships are often among the longest lasting relationships between people, and more than two-thirds of adolescents with siblings introduce their siblings as the most important people in their life. Therefore, the aim of this study was to evaluate the effectiveness of communication skills on sibling relationships among the adolescents with Down syndrome. Methods:  <a c...

This paper examines the impact of sibling rivalry for resources on health outcomes by studying the effect of sibling composition and birth order on the height for age of children below ten years. The paper further tests whether relaxing resource constraints reduces the impact of sibling rivalry. This paper also examines sibling gender effect on the health outcomes for young boys and girls. JEL ...