Children of the 1950s

From infancy to adulthood - a study of health in Aberdeen

Children of the 1950s
Summary of results
February 2005

The ‘Children of the 1950s’ study began in 1962 when researchers surveyed all the primary school children in Aberdeen aged 7-12 years. At the time they were interested in investigating the occurrence and causes of learning disabilities in a distinct population.

Now, over 40 years later, scientists are using the data collected along with current information collected via a postal questionnaire. Their aim is to investigate the factors in infancy and childhood which can shape health and disease in adult life. New research suggests size at birth, growth in childhood and social circumstances can all have an affect. If we can understand some of the causes of ill health, it may help us to produce preventative measures for the future.

1. Tracing the study members
2. Questionnaire response
3. Ensuring the data is valid
4. Heart disease
5. Pregnancy
6. Intelligence
7. Across the generations
8. Schooling
9. Mental health

1. Tracing the study members
We attempted to trace 12,150 of the children in the original school survey in 1962 who were born in Aberdeen. By March 2004 we had found over 97% of the population of whom 477 were deceased and 288 were known to have emigrated from the UK. Of those still found to be living in the UK, 81% still lived in Scotland while 73% were in Grampian region.

By looking at the data collected in the 1960s and comparing who had moved away and who had not, we found that children who were taller, from higher social classes and those who did better at school tests were more likely to have moved away from Grampian.

2. Response to the questionnaire
We mailed more than 11,000 study members of whom over 7,000 (64%) completed and returned the questionnaire. This is a good rate of response compared to other similar postal research surveys. We were keen to have as big a response as possible as if any section of the population are not represented this could affect the way we view our results. Encouragingly for the study researchers, 95% of those who responded to the questionnaire were willing to take part in future surveys.

We found that slightly more women than men responded. Those who had better primary school test results were more likely to return the questionnaire, as were those who had fewer siblings, were taller, heavier and those whose father was in a non-manual occupation at the time of their birth.

3. Ensuring the data is valid
An important part of our work is to ensure the data we are using is valid. We therefore looked at how the answers in the questionnaire relating to father’s occupation matched up with answers given in the original study in 1962. We found a degree of difference between the two that was enough to affect the interpretation of results. We could therefore suggest that in similar studies, data collected where participants recall past events should be used with caution.

4. Heart disease
Coronary heart disease and stroke are amongst the biggest killers in Scotland today. We were therefore keen to look at their prevalence in this population and any possible explanations as to why some people are more likely to suffer than others.

First of all we found that social class at birth was associated with lifestyle behaviours in adult life such as smoking, binge drinking and being overweight. These factors are known to be risk factors for heart disease. Those in the higher social classes were on average less likely to have these ‘risky’ behaviours. There is evidence from the data that levels of education may be an important factor here.

Those study members who had a father in a higher social class according to occupation were less likely to suffer from heart disease than those in the lower classes. Coronary heart disease and stroke were also more prevalent in those with a lower weight at birth. This has been shown in other similar studies of previous generation, but it is interesting that we have found it to be the case in more recent times. Interestingly, we did not find any association between being obese or overweight at primary school age and increased risk of heart disease in adult life. It may be that if weight had been measured later in childhood or in adolescence an increase in risk would have been apparent.

5. Pregnancy
Differences in temperature during the pregnancies of the mothers of the ‘Children of the 1950s’ affected birth weight of their offspring. The explanation for this is unclear as yet, but this is of interest if weather patterns are changing to more extreme conditions as is suspected.

Raised blood pressure in pregnancy is one of the most common complications, but the causes are not known. We examined the links between poor social circumstances in childhood and this condition. Results indicate that women who lived in poorer childhood circumstances as children were at greater risk of a severe from of high blood pressure known as pre-eclampsia. Unfortunately information on smoking in pregnancy was limited. Ideally we would like to have factored this into our results.

6. Intelligence
It is known that intelligence in childhood is an indicator for state of health in later adult life. If we knew what factors determine IQ in early life, it may help us to understand how it is related to health. These factors may be social and biological. In this study we found that height in childhood, growth before birth, characteristics of the mother and, especially, father’s social class could be related to IQ as measured by performance in school tests at age 7,9 and 11 years.

Season of birth also appeared to have a small effect on how children in this study performed in school tests. This effect was found to be due to the differences in the age at school entry as this depends on the time of year you were born.

7. Across the generations
By linking the female members of the study to the birth records of their own children we have shown that the size at birth of the offspring is related to that of their mother. This is separate from the mother’s growth and circumstances throughout her own life.

8. Schooling
One of the questions researchers wanted to ask was ‘Can the school you attend influence your later health’. While there was a difference between the average health of those attending different schools, this seemed to be due to the composition of the school intake of pupils rather than a direct influence by the school.

9. Mental health
Low birth weight not due to prematurity was related to adult psychological health in this study. It may be that this is due to impaired development of the brain during growth in fetal life. More research is required to find a possible mechanism.

We hope to keep you updated on future findings. If you have any further questions please contact the study co-ordinator Heather Clark at the University of Aberdeen on 0800-015-2269