Child Growth: The Long View

http://www.esrc.ac.uk/

The Project in a Nutshell

I was principal investigator (PI) on a three-year project made possible by generous funding from the Economic and Social Research Council (ESRC). We reconstructed the growth pattern of British children between 1850 and 1990 to determine how improvements in nutrition, sanitation and medical knowledge influenced children's growth during this period. I also explored factors influencing change in the growth pattern in Japan.

As a part of the grant I also organised the conference 'Stunting: Past, Present, Future' which brought 45 researchers and development professionals to LSE in September 2017. The conference website is available here and you can read a report summarising the conference's findings here.

You can visit the project website here.


Key Research Findings

The Growth Pattern of British Children

Using a new dataset of individual-level, longitudinal measures of growth for boys enrolled in training ships, Pei Gao and I looked at how boys’ heights at a particular age and their velocity of growth changed from those born in the 1850s to those born in the 1970s. There are two important findings. First, the fastest growth in height took place during the interwar period, mirroring results for adults found by Hatton (2014). Second, looking at the boys’ velocity of growth, we find that boys born before 1910 did not experience a strong pubertal growth spurt. However, from the 1910s onward, boys began to experience the rapid pubertal growth that is observed in most developed countries today. These results contradict earlier conclusions on historical children’s growth and give economic historians a better understanding of how the secular increase in mean adult height has been achieved in the past 150 years.

Sample-Selection Bias in Historical Sources of Children’s Growth

Recent scholarship (Bodenhorn et al., 2017), has highlighted that sample-selection bias can be important in historical sources of adult stature. However, no one had looked at the potential for sample-selection bias in historical sources of children’s growth. Using data collected as a part of the grant and other historical data, I found that there is evidence of sample-selection bias in many sources of children’s growth which needs to be taken into account when trying to understand how the growth pattern of children has changed.

Understanding Changes in the Growth Pattern of Japanese Children

In seeking to compare the results for Britain with other countries around the world, I became aware of rich data on children’s growth in Japan. Working with Kota Ogasawara (Chiba University), we used prefecture-level data of mean heights of boys and girls in the interwar period to answer two questions: (1) how important was the disease environment in infancy in shaping the growth pattern of children? and (2) were shocks to child health more salient in the first thousand days of life, often held as a critical window to prevent stunting, or at later ages? We find that infant mortality in early life did not have a strong influence on the growth pattern of children, but there were meaningful effects of infant mortality on child height at ages 6–11. This suggests that interventions outside of the thousand-day critical window can be effective and that the secular increase in height in interwar Japan was more strongly influenced by cumulative responses to the health environment across child development rather than simply improvements in early life health.

We have also extended the data to the post-war period to understand how food shortages during the Second World War influenced children’s growth. Again, we find that children who experienced the war in late childhood and adolescence were more strongly affected by the nutritional shortage than children exposed to the war in infancy and early childhood.

Training Ships

Two of the datasets were based on the extensive records from two training ships, the Exmouth based in London (1876-1925) and the Indefatigable based in Liverpool (1865-1995).

  • The Boys’ Record Books and Admission and Discharge Register of the training ship Exmouth, held at the London Metropolitan Archives, contain 14,000 boys.
  • The Cadet Records for the training ship Indefatigable, held at the Maritime Archives and Library (MAL) in Liverpool, contain 10,450 boys.

Both training ships were founded to prepare working class and pauper boys for careers in the Navy or the merchant marine, but unlike the earlier Marine Society data, there were no minimum height requirements on the Indefatigable. The boys generally entered the ships at age 10 to 14 and were discharged by the age of 15 to 18. Critically, their height and weight were recorded at entry onto and at discharge from the ship, providing a longitudinal measure of their growth. In addition, the ships’ records were incredibly consistent over the 50-150 year period.

Research Outputs

Research Papers

Policy Documents

Datasets