Sibship Size, Height and Cohort Selection: A Methodological Approach

This article deals with the historical relationship between the number of siblings in a family or household and height, a proxy for biological living standards. Ideally, this relationship is better assessed when we have evidence on the exact number of siblings in a family from its constitution onwards. However, this generally requires applying family reconstitution techniques, which, unfortunately, is not always possible. In this latter case, scholars must generally settle for considering only particular benchmark years using population censuses, from which family and household structures are derived. These data are then linked to the height data for the young males of the family or household. Height data are generally obtained from military records. In this matching process, several decisions have to be taken, which, in turn, are determined by source availability and the number of available observations. Using data from late 19th-century Catalonia, we explore whether the methodology used in matching population censuses and military records as described above might affect the relationship between sibship size and biological living standards and, if so, to what extent. We conclude that, while contextual factors cannot be neglected, the methodological decisions made in the initial steps of research also play a role in assessing this relationship.

Sibship size, birth order and risk of asthma and allergy: protocol for a systematic review and meta-analysis

IntroductionThe hygiene hypothesis suggests that reduced exposure to microbes might have contributed to the increase in prevalence and incidence of asthma and allergy observed during the second half of the last century. Following this proposal, several studies have investigated the role of sibship size and birth order in the development of asthma and allergic diseases, but the underlying evidence is conflicting. The objective of the present systematic review will be to identify, critically appraise and synthesise previous primary studies investigating the association of sibship size and birth order with the risk of asthma and allergic diseases.Methods and analysisThe following databases will be searched: AMED, CABI, CINAHL, Embase, Google Scholar, OAIster, Open Access Theses and Dissertations, Open Grey, ProQuest Dissertations & Theses Global, PsycINFO, PubMed, SciELO, Scopus, Web of Science and WHO Global Index Medicus. Studies published up until 31 December 2020 will be eligible. There will be no restrictions by language and geographical location. Risk of bias in the included studies will be assessed using the Effective Public Health Practice Project quality assessment tool. The produced evidence will be synthesised narratively, and studies that present comparable numerical data will be included in meta-analyses using random effects model.Ethics and disseminationOnly data from the published literature will be included in this systematic review. Therefore, no ethical approval is required. The final review paper will be published in a peer-reviewed journal.PROSPERO registration numberCRD42020207905.

New Structure, Traditional Essence: Patterns of Helping Non-Coresident Parents by Own and Sibling(s)’ Gender in China

As Chinese households are becoming smaller with increasing numbers of adult children and older parents living apart, the extent to which patterns of parental support reflect traditional gender dynamics is under debate. Integrating theories of sibling compensation with ceremonial giving, we tested whether helping non-coresident parents in China is affected by sibship size and how these patterns depend on own and sibling(s)’ gender using a sample of 4,359 non-coresident parent-child dyads nesting within 3,285 focal adult children from China Health and Retirement Longitudinal Study 2013. Opposite to patterns in the United States and Europe, we found substitutions of daughters with sons—having more brothers was associated with daughters’ reduced probabilities and hours of helping. Sons’ patterns of helping were independent of number of brothers and sisters in the family, consistent with the theory of ceremonial giving. These findings reflect the dominance of traditional family dynamics despite changes in family structure.

The increasing influence of siblings in social mobility. A long-term historical view (Barcelona area, 16th-19th centuries)

Parental influence over children’s status attainment has historically been argued to be key. However, the cross-sibling influence has been scarcely studied for historical periods and for steam family societies, being the most long-lasting relationship across individuals’ lives once childhood was surpassed. We investigate how intra-generational family relationships determine the social destiny of siblings taking a long-term perspective (16th and the 19th centuries) for Barcelona and its hinterland, using the unique data compiled in the Barcelona Historical Marriage Database. This region was one of the most dynamic economic area in Southern Europe. We found the emergence of the figure of first-married siblings as determinants in the status attainment of other brothers and sisters and a decline in parental influence from the 18th century onwards for all social groups, denying a sibling competing model. This influence worked differently over time depending on sex. First-born sisters with exogamous marriages had a higher influence than first-married brothers on the social mobility of the rest of siblings along the 16th and 17th century. Conversely, from the 18th century onwards, first-married brothers had a higher ascendancy than first-married sisters. Sibship size and the siblings’ marriage order did not contribute to explain these effects. These results can be interpreted in light of an increase in life expectancy of adult population and a change in the occupational structure due to an early industrialization and in affectivity in the18th century.

Analysing Effects of Birth Order on Intelligence, Educational Attainment, Big Five, and Risk Aversion in an Indonesian Sample

Few studies have examined birth order effects on personality in countries that are not Western, educated, industrialized, rich, and democratic (WEIRD). However, theories have generally suggested that interculturally universal family dynamics are the mechanism behind birth order effects, and prominent theories such as resource dilution would predict even stronger linear effects in poorer countries. Here, we examine a subset of up to 11 188 participants in the Indonesian Family Life Survey to investigate whether later–borns differ from earlier–borns in intelligence, educational attainment, Big Five, and risk aversion. Analyses were performed using within–family designs in mixed–effects models. In model comparisons, we tested for linear and non–linear birth order effects as well as for possible interactions of birth order and sibship size. Our estimated effect sizes are consistent with the emerging account of birth order as having relatively little impact on intelligence, Big Five, and risk aversion. We found a non–linear pattern for educational attainment that was not robust to imputation of missing data and not aligned with trends in WEIRD countries. Overall, the small birth order effects reported in other studies appear to be culturally specific. © 2020 The Authors. European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology

Sibship size and educational attainment of Canadian baby boomers

PurposeThe present study assesses how sibship size affects child quality as measured by educational attainment.Design/methodology/approachThe data are from the Canadian General Social Surveys (GSS) of 1986, 1990, 1994 and 1995. The sample is restricted to the individuals born in Canada between 1946 and 1965, that is, the baby-boom generation. In addition to controlling for parental education, the sibship size is instrumented by a non-binary variable created based on the sex composition of the sibship. While most previous studies have pooled both genders, the present paper produces by gender estimatesFindingsThe OLS estimates are statistically significant, negative and moderately large for both male and female baby boomers. When the sibship size is instrumented, the estimates indicate that one additional sibling had reduced the educational attainment of male baby boomers by almost half a year. No causal effect for the sibship size is found for female baby boomers.Originality/valueThis is the first paper on the effects of sibship size on educational attainment, using Canadian data.