Are inequalities in height narrowing? Comparing effects of social class on height in two generations

Abstract

Objective: To determine whether social inequalities in height change across generations. Methods: The target population was from the 1958 British birth cohort, all born 3rd-9th March 1958, followed to 1991, and the offspring of one third of this population. Main outcomes were height measured at 7, 11, 16, and 33 years (cohort members) and once at 4-18 years (offspring). Multilevel models applied to associations of social class of origin with (a) child-to-adult growth trajectory (cohort members), (b) height (offspring), and (c) generational height increment. Results: Height inequalities were observed among cohort members, with differences .2.0 cm at all ages between classes I and II, and IV and V. By adulthood, the difference in mean height had declined significantly in boys and slightly in girls. A secular trend was seen between the two generations. While male offspring had a similar mean height to their fathers in classes I and II, boys in classes IV and V gained 2.1 cm (p,0.001). Height gains of female offspring were evident in all classes, with a greater gain in classes IV and V (non-significant). The social class effect on height was weaker among offspring, with a difference between classes I and II, and IV and V of less than 1 cm. Conclusions: Social inequalities in height observed among the cohort weakened substantially in the next generation due to a greater height gain among offspring from manual classes. Inequalities in childhood height have narrowed between the two generations in this study.

Relationship between childhood short stature and academic achievement in adolescents and young adults – a longitudinal study

“…Our study findings support the view that the association between height and academic achievement persists, though may be weakening over time 8 . In a study of five successive cohorts of 18‐year‐old Danish men conscripted to the military, 7 overall mean height increased and the positive correlation between height, intelligence, and educational attainment decreased over successive cohorts.…”

Maternal education inequalities in height growth rates in early childhood: 2004 Pelotas birth cohort study

“…Socio‐economic inequalities in height among children have been previously described among high‐income 12,15,28,29 as well as low‐ and middle‐income countries 30–34 . However, this association has not been confirmed everywhere.…”

Socioeconomic inequalities in height, leg length and trunk length among children aged 6.5 years and their parents from the Republic of Belarus: Evidence from the Promotion of Breastfeeding Intervention Trial (PROBIT)

“…Height in childhood is a good predictor of height in adulthood and, although shortfalls in height developed during childhood are reduced by adulthood, differences remain after puberty (Li et al 2004b). Some studies suggest that childhood height inequalities may have diminished in developed countries, mainly due to greater height gain within manual social groups (Mackenbach 1991; Li et al 2004a). For example, differences in height among British children aged 7 years, comparing those from semi/unskilled manual families to those from professional/managerial families, reduced from ~ 2 cm shorter to less than 1 cm shorter over two generations (Li et al 2004a).…”

“…Some studies suggest that childhood height inequalities may have diminished in developed countries, mainly due to greater height gain within manual social groups (Mackenbach 1991; Li et al 2004a). For example, differences in height among British children aged 7 years, comparing those from semi/unskilled manual families to those from professional/managerial families, reduced from ~ 2 cm shorter to less than 1 cm shorter over two generations (Li et al 2004a). However, in some developed countries, disparities in childhood height are still marked (Batty and Leon 2002; Freitas et al 2007).…”