Across a wide range of taxa, larger mothers produce larger offspring. Theory assumes that larger, more fecund mothers create higher local densities of siblings, and so larger mothers produce larger offspring to offset sibling competition. This assumption has been debated for over 30 yr, but direct empirical tests are surprisingly rare. Here, we test two key assumptions of classic theories that ...

In the central nervous system (CNS) of Drosophila embryos lacking regulator of cyclin A (rca1) or cyclin A, we observe that several ganglion mother cells (GMCs) fail to divide. Whereas GMCs normally produce two sibling neurons that acquire different fates ('A/B'), non-dividing GMCs differentiate exclusively in the manner of one of their progeny ('B'). In zygotic numb mutants, sibling neuron fat...

Purpose of the Study This study examined whether caregiving has a differential effect on the well-being of sibling caregivers relative to other caregiving groups and whether race moderates this effect. Design and Methods Using the National Survey of Midlife Development in the United States, 631 family caregivers (including 61 sibling caregivers) and 4,944 noncaregivers were identified. Hierar...

Foster children are at high risk for perpetrating and for being victims of sibling aggression and violence. This article proposes an integrative, multidimensional model for studying risk and protective factors of sibling violence. In the model, exposure to sibling violence (perpetration and victimization), child mental disorder, and placement characteristics are risk factors for impaired psycho...

This study examined factors influencing involvement of siblings of individuals with developmental disabilities in future planning and their expectation of future caregiving. The sample consisted of 139 adult siblings recruited from an online sibling list and a sibling conference. Results indicated that few families made plans or involved siblings in the planning. Siblings who were most involved...

This study examined communication interaction patterns when one sibling had a developmental disability as well as the role of communication skills in sibling relationship quality. Thirty sibling dyads were categorized into one of three communication status groups: emerging, context-dependent, and independent communicators. Independent communicators and their siblings did not differ in terms of ...

Sibling relationships have a substantial and lasting effect on children's development. Many siblings experience some occasional conflict, however, up to 40% are exposed to sibling bullying every week, a repeated and harmful form of intrafamilial aggression. We review evidence on the precursors, factors relating to peer bullying, and mental health consequences of sibling bullying. Parenting qual...

Sibling sexual offending has received limited empirical attention, despite estimates that approximately half of all adolescent-perpetrated sexual offenses involve a sibling victim. The present study addresses this gap by examining male adolescent sibling (n = 100) and nonsibling offenders (n = 66) with regard to maltreatment histories and scores on two adolescent risk/need assessment instrument...