Scottish Mental Survey of 1947

Contains correspondence, minutes, reports and coded tabulated statistics relating to the Scottish Mental Survey undertaken in 1947.

c.1947-1975

2 boxes

In 1947 the Population Investigation Committee (PIC) began a survey in collaboration with the Scottish Council for Research in Education (SCRE) to examine the trend of intelligence in Scotland and to test the hypothesis that because of differential fertility, national fertility was likely to fall. The Survey covered approximately 87,000 children born in 1936 who were given the same intelligence test as that administered in the 1932 Scottish Inquiry, and an individual was questionnaire completed. A more detailed questionnaire was completed by a random sample of all children born on the first 3 days of each month in 1936, the '36 day sample', and individual Binet tests were applied to a random sample of all children born on the first day of each alternate month in 1936, the '6 day sample'. A proportion of children were double tested in order to have comparable data to translate the 1947 I.Qs into 1932 units as the Binet tests were different. The mean score of all the children was higher than that of 1932. The result of the survey showed that there had been no fall in measured intelligence since the previous inquiry. The preliminary results were published in The Times in Nov 1948 by Godfrey Thompson.

In 1949 The trend of Scottish intelligence: a comparison of the 1947 and 1932 surveys of the intelligence of eleven-year-old pupils, was published by the SCRE. The work of the Survey falls broadly into three sections. The first part the social survey of 11 year olds in Scotland, with the data used to show the distribution of children among different types of schools, frequency of attendance, the number of schools previously attended, the incidence of physical defects, variation in height and weight, with these characteristics examined against the background of parental occupation and size of family. The second part included an analysis with specific reference to the performance of the children in the intelligence tests of 1947 in relation to the 1932 results. The third part involved a general examination of the relationship between intelligence and social and biological factors. For example the survey yielded the largest collection of data on the intelligence resemblance of twins. An article entitled 'The intelligence of twins. A comparative study of eleven-year-old twins' by J. Maxwell and S.N. Mehrotra was published in Population Studies in 1949.

The Nuffield Foundation provided funds for a follow-up study of the Scottish children with the work carried out by the Joint Mental Survey Committee, which included a representative of the PIC. Another publication appeared in 1953, Social Implications of the 1947 Mental Survey, by James Maxwell. A follow-up sample of 1200 children included in the 6-day sample was begun in 1950 and continued throughout the 1950s. When the follow-up commenced it was decided to give the same intelligence test to the younger siblings when they attained the age at which the child in the sample had been tested, i.e. 11 years old. A third volume, Eleven Year Olds Grow Up, by John Macpherson was published in 1958 to deal with the period 1947-1954.

In 1963, the survey remained in touch with 1037 of the original 1208 members. Data on the higher education of sample members made was also available to the Robbins Committee. In 1963 a report was prepared to cover the age period 18-26 years old. The present activities of the Mental Survey Committee ceased with the publication of this report. A further follow-up survey was suggested to look at the children of members of the sample and measure their intelligence as they reached 11 years old. The final report of the Mental Survey Committee was published in 1967 covering the careers of the 6-day sample members from 1947-1964. Although the follow-up survey had ceased, one aspect continued - an annual search of the records of the Registrar General for the marriages of members and the births of their children.