Can resource dilution explain differences in height by birth order and family size? A study of 389,287 male recruits in twentieth-century Netherlands

Relationship between Birth Order and Postnatal Growth until 4 Years of Age: The Japan Environment and Children’s Study

Later-borns tend to be shorter than first-borns in childhood and adulthood. However, large-scale prospective studies examining growth during infancy according to birth order are limited. We aimed to investigate the relationship between birth order and growth during the first 4 years of life in a Japanese prospective birth cohort study. A total of 26,249 full-term singleton births were targeted. General linear and multivariable logistic regression models were performed and adjusted for birth weight, parents’ heights, maternal age at delivery, gestational weight gain, maternal smoking and alcohol drinking status during pregnancy, household income, breastfeeding status, and Study Areas. The multivariate adjusted mean length Z-scores in “first-borns having no sibling”, “first-borns having siblings”, “second-borns”, and “third-borns or more” were −0.026, −0.013, 0.136, and 0.120 at birth and −0.324, −0.330, −0.466, and −0.569 at 10 months, respectively. Results similar to those at 10 months were observed at 1.5, 3, and 4 years. The adjusted odds ratios (95% confidence intervals) of short stature at 4 years in “first-borns having siblings”, “second-borns”, and “third-borns or more” were 1.08 (0.84–1.39), 1.36 (1.13–1.62), and 1.50 (1.20–1.88), respectively, versus “first-borns having no sibling”. Birth order was significantly associated with postnatal growth and may be a factor predisposing to short stature in early childhood.

Health outcomes of only children across the life course: An investigation using Swedish register data

Only children (with no full biological siblings) are a growing subgroup in many high-income settings. Previous studies have largely focused on the short-term developmental outcomes of only children, but there is limited evidence on their health outcomes. Using Swedish population register data for cohorts born 1940-75, we compare the health of only children with that of children from multi-child sibling groups, taking into account birth order, family size, and presence of half-siblings. Only children showed lower height and fitness scores, were more likely to be overweight/obese in late adolescence, and experienced higher later-life mortality than those with one or two siblings. However, only children without half-siblings were consistently healthier than those with half-siblings, suggesting that parental disruption confers additional disadvantages. The health disadvantage was attenuated but not fully explained by adjustment for parental characteristics and after using within-family maternal cousin comparison designs.

Socioeconomic factors and intergenerational differences in height of Portuguese adults born in 1990: results from the EPITeen cohort

Average adult height is an indicator of population health and a marker of socioeconomic inequalities. This study aimed to assess how socioeconomic differences affect intergenerational height increase between adults born in 1990 and their parents. Data from a population-based cohort of subjects born in 1990 (EPITeen) were analysed. Participants' adult height was objectively measured. Parental height, education, and occupation were reported by the parents. The height difference between daughters and their mothers (n=707), and sons and their fathers (n=647) was calculated. A generalised linear model was used to assess the association between parental education and occupation, separately, and the intergenerational height difference, adjusted for maternal age at birth, smoking during pregnancy, birthweight adjusted for gestational age, and birth order. Females were on average 1.46cm (SD=6.62) taller than their mothers, and males 3.00cm (SD=7.26) taller than their fathers. The highest height gain was shown in those with less advantaged socioeconomic background. In the adjusted model, sons whose mothers had 0-6 years of education grew 3.9cm taller (β=3.894; 95%CI:2.345;5.443) and daughters 1.5cm taller (β=1.529; 95%CI:0.180;2.878) (compared to >12y maternal education); for paternal education, sons and daughters grew 3.5cm (β=3.480; 95%CI:1.913;5.047) and 1.9cm taller (β=1.895; 95%CI:0.526;3.265), respectively. A higher height increase was found in participants with less advantaged maternal and paternal occupational level. Adults born in 1990 are taller than their parents, and height gain was higher in males than females. Adults from a lower socioeconomic status experienced the highest height gain, suggesting a reduction in height inequality.

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.

Homemakers and heights. Intra-household resource allocation and male stature in the Netherlands, 1860-1930

In this article we test the hypothesis that the secular increase in heights in the course of the second half of the nineteenth century was associated with the rise of the breadwinner-homemaker household. In these 'modern' households, women raised the living standards (quality and quantity of food, hygiene and care) for all members, especially the children. We model the assumed contributions to the family budget by age and gender of household members, and find that a strong imbalance between consumers and producers in the household put severe strains on effective resource allocation, leading to lower net nutrition and lower young adult heights. We suggest a carefully calibrated consumer/producer ratio as an indicator to capture these effects. The ratio is not meant to replace others, and we show that sibling rank order as well as gender preferences also played a role in intra-household resource allocation. For our research, we have used a database with reconstructed life histories (including co-residence) of 3003 Dutch army recruits. Our results indicate that the consumer/producer ratio as experienced by recruits in their early life indeed had a strong impact (-1,8 cm) on their heights. However, this effect differed by social class, which can be explained by differences in acceptance of the income pooling model.

WOMEN’S EMPOWERMENT AND GENDER INEQUALITY IN ADOLESCENT NUTRITIONAL STATUS: EVIDENCE FROM THE INDONESIAN FAMILY LIFE SURVEY

In contrast to the extensive knowledge on the association between women’s empowerment and the nutritional status of children under the age of five, relatively little is known about the influence of women’s empowerment on adolescents’ nutritional status. This study aimed to assess the association between women’s empowerment and gender inequalities in adolescent nutritional status. Data were from the Indonesian Family Life Survey (IFLS) covering the period 1997 to 2015, and consisted of 16,683 observations from 13,396 adolescents between the ages of 10 and 19 years born in 6781 families. Three indicators of women’s empowerment were used: mother’s education, mother’s bargaining power and mother’s working status. Multivariate linear regression with robust standard errors was used to examine whether and how these indicators of women’s empowerment influenced adolescent nutritional status. Interaction terms were added to analyse how the association between women’s empowerment and adolescent nutritional status differed by gender. The results showed that mother’s education and mother’s working status were significantly associated with adolescent nutritional status, particularly with height-for-age. Adolescents of well-educated mothers had a higher height-for-age while those who were raised by mothers with a blue-collar job had a lower height-for-age. Although no gender differences were found for height-for-age, gender differences for BMI-for-age were obvious, with boys having a lower BMI-for-age than girls. Interactions between indicators of mother’s empowerment and gender showed that the gender gap in BMI-for-age was smaller for adolescents of more educated mothers. However, further analyses of food consumption patterns showed that boys whose mothers were more educated consumed more fast food and had higher instant noodle consumption than girls, thus suggesting gender bias in new disguise.