Growing up with multiple siblings might negatively affect language development. This study examined the associations between birth order, sibling characteristics and parent-reported vocabulary size in 6163 Norwegian 8- to 36-month-old children (51.4% female). Results confirmed that birth order was negatively associated with vocabulary, yet…

Emotion understanding develops rapidly in early childhood. Firstborn children (N = 231, 55% girls/45% boys, 86% White, 5% Black, 3% Asian, 4% Latinx, Mage = 29.92 months) were recruited into a longitudinal study from 2004 to 2008 in the United States and administered a series of tasks assessing eight components of young children's emotion…

Issues of equality and fairness and invasion of the personal domain, 2 previously identified topic areas of adolescent sibling conflict (N. Campione-Barr & J. G. Smetana, 2010), were examined in 145 dyads ("M" [subscript first-born] = 14.97, "SD" = 1.69 years; "M" [subscript second-born] = 12.20,…

Longitudinal data were obtained from 157 children aged 3 years 3 months to 5 years 6 months at Time 1. At Time 2 these children had aged an average of 12 months. Theory of mind (ToM) and executive functioning (EF) were measured at both time points. Results suggest that Time 1 ToM scores predict Time 2 EF scores. Detailed examination of sibling…

Research suggests that sibling--peer connections are important for understanding adolescent problem behaviors. Using a novel behavioral genetic design, the current study investigated peer network overlap in 300 child--child pairs (aged 7-13 years) in 5 dyad types: monozygotic (MZ), dizygotic twins, full siblings (FSs), friend pairs, and virtual…

Longitudinal patterns in parents' reports of youth decision-making autonomy from ages 9 to 20 were examined in a study of 201 European American families with 2 offspring. Multilevel modeling analyses revealed that decision-making autonomy increased gradually across middle childhood and adolescence before rising sharply in late adolescence. Social…

The current study examined whether parental and contextual risk factors contribute to mothers' and fathers' differential treatment (MDT/FDT) when accounting for sibling dyad characteristics. Also explored was whether family type (single mothers vs. 2 parents) moderated the links between the parental and contextual correlates and MDT. One hundred…

Sixty-four sibling dyads (4-12 years old; 61% males; 83% European-American) were asked to resolve an ongoing conflict. Older siblings provided leadership by suggesting, modifying, justifying, and requesting assent to plans for conflict resolution. Younger siblings countered and disagreed, but also contributed to planning and agreed to their…

This study charted the development of gendered personality qualities and activity interests from age 7 to age 19 in 364 first- and second-born siblings from 185 White, middle/working-class families, assessed links between time in gendered social contexts (with mother, father, female peers, and male peers) and gender development, and tested whether…

Observed in a laboratory setting how dyads, ages 4 and 6 years or 6 and 8 years, negotiated division of toys. Found that children used a preponderance of constructive problem-solving strategies rather than contentious tactics. Degree of conflict of interests and quality of sibling relationships predicted use of problem-solving and contentious…

Examined associations between the activity level and adaptability of same-sex siblings and qualitative aspects of their relationship. Found high levels of conflict when both siblings were high in activity and the older sibling was rated more active than the younger. Conflict was lowest when siblings were low in activity. Warmth was greatest when…

Examined association of three maternal regulating behaviors with children's positive and negative behaviors toward siblings in 40 Japanese families. Observed maternal regulating behaviors more frequently when younger sibling was still in early developmental stage. Older siblings' negative behaviors toward younger positively correlated with…

Mothers' and fathers' responses to their children's spontaneous sibling conflicts were observed. Findings indicated that associations between parents' conflict management strategy and sibling interaction quality varied according to children's ages, gender of the monitoring parent, and type of strategy. Passive nonintervention was highly associated…

Five experiments examined children's understanding of logical consistency. Findings indicated that only by 6 years of age were logically inconsistent claims understood despite good memory for claims, varying question forms, ability to identity other types of statements as not sensical or to compare/contrast claims in other ways, and attempts made…

Changes in sibling intimacy and conflict were charted from middle childhood through adolescence, and family structure and relationship correlates of change were examined. Participants were mothers, fathers, and firstborn (M=11.82 years at Time 1) and secondborn (M=9.22 years) siblings from 200 White, working/middle class, 2-parent families.…