Second-born Siblings Research Articles

Birth order, conscientiousness, and openness to experience: Tests of the family-niche model of personality using a within-family methodology

We investigated differences between firstborn and secondborn siblings on major dimensions of personality, in the context of the proposal of Sulloway [Sulloway, F. J. (1996). Born to rebel: Birth order, family dynamics and creative lies. New York: Pantheon] that personality is influenced by the specialized niches siblings adopt in the quest for access to parental resources. Using a within-family methodology, we tested two predictions from Sulloway's model: that firstborns are more achieving and conscientious than secondborns and that secondborns are more rebellious and open to new experiences than firstborns. To test an alternative prenatal hypomasculinization theory proposed by Beer and Horn [Beer, J. M., & Horn, J. M. (2000). The influence of rearing order on personality development within two adoption cohorts. Journal of Personality, 68, 769–819], we also examined the size of birth-order effects in sister–sister versus brother–brother pairs. The hypothesized effects of birth order on personality were found in both Study 1 ( n=161 sibling pairs) and Study 2 ( n=174 sibling pairs) and provided support for Sulloway's family-niche model. No support was found for Beer and Horn's hypomasculinization model.

P.194 Spread of the natural hepatitis C virus recombinant outside Russia

Autism is predominantly genetically determined. Evidence supports familiality of the main sets of behavioral characteristics that define the syndrome of autism; however, possible non-genetic effects have also been suggested. The present study compared levels of autism symptom domains, as measured by the Autism Diagnostic Interview, and useful phrase speech scores between 106 pairs of first- and second-born siblings from multiply affected families. In addition, the intercorrelations between the measures were compared between siblings. The overall mean repetitive behavior total score was significantly higher (worse) in first-born than in second-born siblings. In contrast, first-born siblings had significantly lower (better) useful phrase speech than their younger siblings. Autism social and non-verbal communication scores were significantly correlated in first- and in second-born siblings. However, there was a significant difference in the coefficients between first- and second-born siblings. Performance on the non-verbal communication domain was also significantly and positively correlated with useful phrase speech score in both first- and second-born siblings. It is unclear at this time whether these results are of biologic origin. Nevertheless, the findings suggest that genetic studies in autism using specific levels of familial autism traits as phenotypes should take into account their intercorrelations and birth order effects embedded in the instrument.

Gerontologic nurse practitioner care guidelines: Assessing and managing hearing deficits in the older adult

This paper studies whether sibling gender affects personality traits. We use the idea that if parents decide to have a second child, it is random whether they will have a boy or a girl. Therefore, the relationship between the second-born sibling's gender and the first sibling's personality traits is causal. We employ longitudinal data from a large British cohort which is followed from birth onwards. The dataset includes personality traits at age 10 and 16. Our main result is that oldest boys in a household are more agreeable if their next-born sibling is a girl. This effect is robust across age (10 and 16), when controlling for among others family size, and when applying corrections for multiple hypothesis tests. Agreeableness is an important trait in life as it has been shown to correlate positively among others with being employed, having a skilled job, savings, and life satisfaction.

Vocabulary competence in first- and secondborn siblings of the same chronological age

We explored vocabulary competence in 55 firstborn and secondborn sibling pairs when each child reached 1;8 using multiple measures of maternal report, child speech, and experimenter assessment. Measures from each of the three sources were interrelated. Firstborns' vocabulary competence exceeded secondborns' only in maternal reports, not in child speech or in experimenter assessments. Firstborn girls outperformed boys on all vocabulary competence measures, and secondborn girls outperformed boys on most measures. Vocabulary competence was independent of the gender composition and, generally, of the age difference in sibling pairs. Vocabulary competence in firstborns and secondborns was only weakly related.

Familial concordance of phenotype and microbial variation among siblings with CF.

The clinical spectrum of cystic fibrosis (CF) is influenced by the cystic fibrosis transmembrane conductance regulator (CFTR) genotype. However, variable courses of the disease were demonstrated among patients with identical genotypes. Since siblings share identical CFTR mutations and environmental factors, they can serve as a model to assess the effect of modifier genes on disease expression, and also to evaluate cross-infection. The aim of this study was to compare disease expression among siblings with CF. All sibling pairs treated at 7 CF centers in Israel were included in the study. Data were collected from patients' medical charts. Fifty families with at least 2 siblings were identified. As expected, the second-born sibling was diagnosed at an earlier age compared to the first-born. The mode of CF presentation at diagnosis showed significant familial concordance. In the families where the first sibling presented with gastrointestinal manifestations, 79% of the second siblings also presented with gastrointestinal manifestations. When gastrointestinal manifestations were absent in the first sibling, only 12% of the second siblings presented with gastrointestinal manifestations (P < 0.0001). Likewise, when the first sibling presented with respiratory symptoms, 60% of the second siblings presented with the similar symptoms. However, when the first sibling presented without respiratory symptoms, only 12% of the second siblings presented with respiratory symptoms (P < 0.001). Meconium ileus (MI) was present in 20 patients (21%). In 10 families where the first-born sibling had MI, 8 (80%) of the subsequent siblings had MI. On the other hand, in the 39 families where the first-born sibling did not have MI, only 2 (5%) subsequent siblings had MI (P < 0.001). Pancreatic insufficiency (PI) also had high familial concordance (P < 0.0001). Percentile growth for weights and heights and lung function (FVC, FEV(1), and FEF(25-75)) at ages 7 and 10 years were similar between siblings. P. aeruginosa grew from sputum in 89% of our study patients. When P. aeruginosa was isolated from the first-born patient, 91% of the second siblings were also positive for P. aeruginosa, whereas when the initial sibling was not a carrier of P. aeruginosa, only 50% of subsequent siblings were positive (P < 0.0001). This familial concordance was not observed for S. aureus. By contrast, the age of first isolation of P. aeruginosa and S. aureus was significantly earlier in the second sibling than in the first for the two bacteria: 10.3 +/- 5.1 vs. 7.3 +/- 5.2 years (P < 0.05) for P. aeruginosa, and 11.5 +/- 5.4 years vs. 6.8 +/- 5.1 years (P < 0.05) for S. aureus. CF siblings tend to share similar phenotypes that are not mutation-dependent. The lack of variability between siblings in mode of initial CF presentation, rates of MI, pulmonary function, and nutritional status supports the role of modifier genes in the determination of these factors.

Association of head circumference at birth among sibling pairs.

The objective of the study was to estimate and compare the correlation coefficients of head circumference and weight at birth among sibling pairs. Pairs of singleton siblings were ascertained among children born in Norway to the same mother between 1978 and 1997. Head circumference, birthweight and other perinatal factors were registered in the Medical Birth Registry of Norway. Head circumference measurements were obtained for first- and second-born in 287 448 sibling pairs. The correlation coefficient of head circumference among first- and second-born siblings was 0.343 (standard error 0.002) compared with 0.477 (standard error 0.002) for birthweight. These results were similar for later-born sibling pairs and only slightly influenced by other factors such as sex, fatherhood and time between pregnancies. Sensitivity analyses showed that substantial measurement error is required to explain the lower correlation for head circumference. In conclusion, the sibling correlation of head circumference was consistently weaker than that of birthweight.

Sibling differentiation: sibling and parent relationship trajectories in adolescence.

Studied here were the links between sibling differences in trajectories of change in the qualities of parent-child relationships and the qualities of sibling relationships across a 2-year period in adolescence. Participants were first- and second-born siblings (M age = 14.94 years for firstborns and M age = 12.46 years for secondborns) from 185 predominantly White, working and middle-class families. In home interviews, siblings reported on their dyadic family relationships. For reports of parent-child warmth but not parent-child conflict, results were consistent with sibling differentiation theory: Increasing differences between siblings over time in parent-child warmth were linked to trajectories of increasing warmth and decreasing conflict in the sibling relationship as reported by firstborns, and increasing warmth in the sibling relationship as reported by secondborns. The findings support the view that sibling differentiation may be a strategy for managing sibling conflict and rivalry.

Birthweight and perinatal mortality: paradoxes, social class, and sibling dependencies.

Birthweight distributions among second-born infants depend on the birthweights of older siblings, with implications for weight-specific perinatal mortality. We wanted to study whether these relations were explained by socioeconomic levels, and to study time trends in a situation with decreasing perinatal mortality rates. Births in the Norwegian Medical Birth Registry from 1967 to 1998 were linked to their mothers through their national identification numbers. The study population was 546 688 mothers with at least two singletons weighing >/==" BORDER="0">500 g at birth. Weight-specific perinatal mortality for second-born siblings in families with first-born siblings in either the highest or the lowest birthweight quartile was analysed. Maternal education and cohabitation status were used as measures of socioeconomic level. For all 500-g categories below 3500 g, mortality rates were significantly higher among second-born infants with an older sibling in the highest rather than the lowest weight quartile. This pattern was the same across three educational levels. The exclusion of preterm births did not change the effect pattern. A comparison of perinatal mortality among second siblings in terms of relative birthweight (z-scores) showed a reversal of the relative risks, although these were only significantly different from unity for the smallest infants. Conclusion The crossover in weight-specific perinatal mortality for second siblings by weight of first sibling is largely independent of socioeconomic level, and is not weakened by the decreasing perinatal mortality rates in the population over time. Family data should be taken into consideration when evaluating the risk of adverse pregnancy outcome relating to weight.

Sibling influences on gender development in middle childhood and early adolescence: A longitudinal study.

The development of gender role qualities (attitudes, personality, leisure activities) from middle childhood to early adolescence was studied to determine whether siblings' gender role qualities predicted those of their sisters and brothers. Participants were 198 firstborn and second-born siblings (Ms = 10 years 9 months and 8 years 3 months, respectively, in Year 1) and their parents. Families were interviewed annually for 3 years. Firstborn siblings' qualities in Year 1 predicted second-born children's qualities in Year 3 when both parent and child qualities in Year 1 were controlled, a pattern consistent with a social learning model of sibling influence. Parental influence was more evident and sibling influence less evident in predicting firstborns' qualities; for firstborns, sibling influences suggested a de-identification process.

When Does Parents’ Differential Treatment Have Negative Implications for Siblings?

We compared the extent of parents’ differential treatment (PDT) and girls’ and boys’ perceptions of parents’ fairness in middle childhood and adolescence as a function of the gender constellation of the sibling dyad. Further, we examined links between PDT in three domains, parental warmth, parents’ temporal involvement, and the allocation of household tasks, and both siblings’ self esteem and positivity in the sibling relationship. Participants were mothers, fathers and both first‐ and secondborn siblings from 385 families. To collect information on siblings’ family experiences and well‐being, family members were interviewed individually in their homes. During the subsequent 2–3 weeks, 7 evening telephone interviews also were conducted; these focused on siblings’ daily activities. Analyses revealed different patterns of PDT for siblings as a function of age and gender constellation, stronger links with self esteem and sibling positivity for perceptions of fairness than for PDT, and different patterns of association with self esteem and sibling relations across domains of PDT. We emphasize the importance of studying the processes through which PDT experiences have implications for siblings.

Attachment concordance among first- & second-born siblings & their mothers

Attachment concordance among first- & second-born siblings & their mothers

The Development of Aggression within Sibling Conflict

Sibling physical aggression and parents' and children's responses to such aggression were observed in 40 families when children were approximately 2% and 4% years of age, and two years later when they were 4% and 6%. Aggression occurred in all families, with first-born siblings being more aggressive than second-borns, and second-born siblings being more likely to cry, especially at the first time period. Parents responded to half of their children's aggression, and were more likely to respond if victims had cried. Only when parents intervened did the conflict resolution indicate to the children that physical aggression was not acceptable. Most responses by both parents and child victims were simple commands to stop aggression, and discussion of issues that gave rise to the aggression. Less frequent parent and child responses, such as physical reactions or approval of aggression by parents, and discussions of feelings or rules, or crying by first-born children were related to only the aggression of second-...

Immunization Status and Birth Order

To determine whether an association exists between immunization status and birth order. Medical record review of immunization dates for matched siblings. Pediatric clinic at a university medical center. A total of 892 children (446 sibling pairs of firstborn and secondborn children) born between 1983 and 1991 who received regular pediatric care at the clinic. Median ages at which firstborn children and their secondborn siblings had been immunized with the initial four doses of diphtheria and tetanus toxoids and pertussis vaccine (DTP1, DTP2, DTP3, and DPT4) and the initial dose of measles-mumps-rubella vaccine; point prevalences of firstborn and secondborn children up-to-date with all immunizations at each month of life to 2 years of age. Between 5 and 12 months of life, the percentage of secondborn children who were fully immunized was significantly lower than the percentage of fully immunized firstborn children (P values ranging from < .0001 to < .05). Firstborn children were much more likely than their secondborn siblings to have been immunized on time with DTP2 (z = 3.80, P = .0001) and DTP3 (z = 3.31, P = .0009). Overall, DTP2 immunizations were given at median ages 10 days later, and DTP3 immunizations, 20 days later to secondborn children than to their firstborn siblings. In addition, late immunization of a firstborn child was found to increase the risk that a secondborn sibling would also be immunized late. Secondborn children are likely to be immunized later than firstborn children. Secondborn children with an older sibling who was immunized late are at particular risk for delayed immunizations.

The Influence of Parents and Siblings on the Development of a Personal Premise System in Middle Childhood

Abstract Children's perceptions of the influence of parental and sibling responsiveness and support were investigated. The sample of 73 Caucasian participants ranging in age from 8 years 0 months to 11 years 2 months (39 first-born children and 34 third-born children) responded to the Piers-Harris Children's Self-Concept Scale (P-H), the Sibling Relationship Questionnaire (SRQ), and the Parent Perception Inventory (PPI). Each P-H was analyzed with a stepwise multiple regression, with gender, PPI, and SRQ as independent variables. Separate analyses were completed for first-born and third-born children. Children's perceptions of the influence of parental and sibling responsiveness and support differed by birth order. For first-born children, second-born sibling warmth was a stronger predictor of self-perceptions than maternal warmth and responsiveness. Mothers' influence on first-born children's self-perceptions was mainly indirect but positive; fathers' influence was direct but negative. On the other hand,...

Maternal Labeling of Gifted Children: Effects on the Sibling Relationship

The present study examined the impact of maternal labeling of children as gifted on the sibling relationship. Subjects were 144 pairs of firstborn and secondborn siblings classified according to maternal perceptions into one of four groups: both gifted, firstborn gifted, secondborn gifted, or neither gifted. Five aspects of the sibling relationship were examined: Warmth/Closeness, Status/Power, Conflict, Maternal Partiality, and Paternal Partiality. Results indicated that unlabeled children generally did not view the sibling relationship more negatively than their labeled siblings. However, there was consistent evidence of labeling effects which interacted with birth order. Maternal labeling of firstborn children was associated with greater Warmth/Closeness in the sibling relationship, but maternal labeling of secondborn children appeared to have the opposite effect of reduced Warmth/Closeness.

Deidentification in Two-Child Families

This study investigated deidentification in relationship to self-ratings, achievement test performance, and grade point average offirst-born and second-born siblings. A sample of 47 adolescent sibling pairs from two-child families rated self and sibling on 13 semantic differential concepts. Results indicated that both first-born and second-born adolescents who judged themselves to be higher achieving that their siblings had higher self-definitions on evaluative and activity scales than did those who judged themselves equally or lower achieving. On achievement measures, however, first-borns who rated themselves as higher achieving than their sibling tended to have significantly higher achievement test scores and higher grade point averages than did other groups, but second-borns tended to have higher scores on these measures when they judged themselves to be equally achieving. These findings were interpreted as support for social comparison theory and as suggesting that intellectual performance may be more salient to first-borns than to second-borns.

Siblings' Reactions to Parental Divorce

Because previous studies of children and divorce have typically included only one child per family, little is known about how siblings in the same family experience their parents' divorce. Three samples, totalling 49 pairs of white middle-class adolescent and preadolescent first-born and second-born siblings whose parents were separated no more than 24 months, were studied to assess the relation between siblings' divorce adjustment and the relation between siblings' general behavioral adjustment. Siblings' self-reports and custodial mothers' ratings of each sibling were obtained. For both sets of data, siblings' scores were positively related; when differences were found, older siblings were better adjusted than younger siblings. Based on siblings' self-report scores, relative to younger siblings, older siblings had a better understanding of the divorce, fewer problematic beliefs regarding the divorce, a better understanding of conflict resolution, and a more internal locus of control. Relative to boy/boy...

Social-emotional adaptation and infant-mother attachment in siblings: role of the mother in cross-sibling consistency.

We investigated concordance in social-emotional behavior and attachment of first- and secondborn siblings from 65 families. Both children were seen at 24 months in a problem-solving procedure and at 12 months in the Strange Situation. Maternal behavior at 24 months also was examined. Child behaviors at 24 months showed trends toward concordance across siblings. Maternal behavior was significantly stable across siblings and correlated significantly with child competence. In post-hoc analyses, the sample was split into 2 groups: maternal behavior stable (N = 36) and maternal behavior unstable. In the first group, cross-sibling correlations were significant and larger than for the whole sample; in the second group, cross-sibling correlations were low and nonsignificant. There also was significant concordance across siblings in attachment classification. These data suggest that it is essential to consider the care received by different children in investigating similarities in siblings' behavior.

Social-Emotional Adaptation and Infant-Mother Attachment in Siblings: Role of the Mother in Cross-Sibling Consistency

We investigated concordance in social-emotional behavior and attachment of first- and secondborn siblings from 65 families. Both children were seen at 24 months in a problem-solving procedure and at 12 months in the Strange Situation. Maternal behavior at 24 months also was examined. Child behaviors at 24 months showed trends toward concordance across siblings. Maternal behavior was significantly stable across siblings and correlated significantly with child competence. In post-hoc analyses, the sample was split into 2 groups: maternal behavior stable (N = 36) and maternal behavior unstable. In the first group, cross-sibling correlations were significant and larger than for the whole sample; in the second group, cross-sibling correlations were low and nonsignificant. There also was significant concordance across siblings in attachment classification. These data suggest that it is essential to consider the care received by different children in investigating similarities in siblings' behavior.

Similarity in the quality of attachment between first- and second-born siblings and their mothers

This study explores the associations between electronic media exposure, age, and socioeconomic status (SES) in a longitudinal sample of 24 infants from English-speaking families. Leveraging Language ENvironment Analysis (LENA) technology, the study seeks to characterize the relation between electronic media exposure and parental and child vocal activity. We analyzed ecologically valid, daylong audio recordings collected in infants’ homes when they were 6, 10, 14, 18, and 24 months old. SES was measured with the Hollingshead Index, and exposure to electronic media and adult and infant vocal activity were measured automatically with LENA. On average, the children in the sample were exposed to 58 min of electronic media daily. We found that electronic media exposure was negatively associated with SES and decreased with child age, but only amongst high-SES families. We also found that electronic media exposure negatively impacted concurrent adult and child vocal activity, irrespective of SES and infant age. The present findings are an important step forward in examining the role of demographic factors in exposure to electronic media and enhance our understanding of the mechanisms through which exposure to electronic media may impact linguistic development in infancy and beyond.