Monika Krzyżanowska

Biosocial correlates of age at menarche in a British cohort

Abstract Background: A large number of biosocial variables have been shown to associate with age at menarche, but the results are inconsistent and differentiate not only between countries but within countries as well. Aim: This study examined age at menarche in a British national cohort in relation to 21 biosocial and anthropometric variables. Subjects and methods: The analyses were based on 4483 girls from the British National Child Development Study (NCDS). Results: The majority of girls reached menarche between 12–14 years of age. Girls from smaller families, those living in the East and South East, South West, West Midlands and Wales regions, in tied housing and uncrowded conditions, not sharing a bedroom, not having free school meals, whose families lived in households without financial problems had started menstruating earlier than their peers from families with lower socioeconomic status. However, when all the significant variables were analysed together significant associations remained only for mother’s age at menarche, height and weight at 7 years, family size and tenure. Conclusions: The results of this study support the hypotheses that intra-uterine growth and conditions in early life as well as socio-economic background are associated with the timing of menarche and that greater childhood growth and better SES are related to earlier menarche.

Impact of social mobility and geographical migration on variation in male height, weight and body mass index in a british cohort

Using a sample of 2090 British father and son pairs the relationships between social and geographical intra- and inter-generational mobility were examined in relation to height, weight and body mass index (BMI). There was much more social mobility than geographical (regional) migration. Social mobility and geographical migration were not independent: socially non-mobile fathers and sons were more likely to be geographical non-migrants, and upwardly socially mobile fathers and sons were more likely to be regional migrants. Upwardly socially mobile fathers and sons were, on average, taller and had a lower BMI than non-mobile and downwardly mobile fathers and sons. In general, no significant associations were found between geographical migration and height or weight. Migrating fathers had a lower BMI than sedentes, as did their sons who migrated between 1965 and 1991. There was no significant interaction that indicated that social mobility and geographical migration were acting in a simple additive way on height, weight and BMI.

Educational and social class assortative mating in fertile British couples

Abstract Background: Positive assortative mating for education and social position has been widely reported in a number of countries, but very few studies have tested whether or not educational or social class homogamy is related to differential fertility. Aim: This study examined the relationship between educational and social class assortative mating and fertility in a British national cohort. Subjects and methods: The analyses were based on 7452 husband–wife pairs from the British National Child Development Study (NCDS). Results: The mean fertility was 3.22 children per couple; the number of children significantly increased from higher to lower social classes and from the more educated to the less educated. The extent of assortative mating for social class and educational level was related to fertility; as educational assortative mating decreased so did the average number of children, whereas the opposite trend was observed for social class. When assortative mating for education and social class were considered together, educational assortative mating was the more significant predictor of the number of children and educationally homogamous couples had higher fertility independent of their social class assortative mating. Conclusions: The relationship between assortative mating and fertility for education and social class appeared to be acting in the opposite direction.

Biosocial correlates of inter-generational social mobility in a British cohort.

The relationship between inter-generational social mobility of sons and daughters between 1958 and 1991 and biosocial variables, i.e. birth order, number of children in family, fathers social class, region, educational attainment of child and father, educational and cognitive test scores (reading, mathematics, verbal and non-verbal IQ tests), was studied in a large British cohort study. The data used were collected as part of the British National Child Development Study (NCDS). The extent of social class mobility was determined inter-generationally and was categorized as none (no change in social class between the fathers and index childs social class), upwardly mobile (where the index child moved up one or more social classes compared with their father) or downwardly mobile (where the index child moved down one or more social classes compared with their father). All of the biosocial variables were associated with social mobility when analysed separately. Multivariate analyses revealed that the most significant predictor of mobility categories in both sexes was education of the cohort member, followed by social class of the father. In both sexes mathematics score was a significant predicator, while in sons reading and non-verbal IQ scores were also important predictors. In the light of these results, it appears that social mobility in Britain takes place largely on meritocratic principles.

Biological aspects of human migration and mobility

Abstract This paper reviews how migration, both geographical and social, impacts on variation in some human biological traits. Migration and mobility are considered in relation to anthropometric traits and indices, psychometric traits, health, disease and nutrition, temperature regulation and metabolism, mental health and gene flow. It is well known that migration is important in disease transmission but, as this paper demonstrates, migration can have both positive and negative impacts on both donor and recipient populations for a wide range of human traits.

Is Human Mating for Height Associated with Fertility? Results from a British National Cohort Study

Very few studies have investigated whether spousal similarity for height is related to fertility. This study examined the relationship between mating for height and fertility after correction for spousal age, social class, education, and region.