1947 SMS Survey

Administrative / Biographical History

The 1947 SMS survey was a repetition of the 1932 survey, but much more extensive, and a wider range of data was collected. Almost everyone born in 1936 attending a Scottish school was tested. It was thought that the IQ of the nation was in decline, and it was also believed that people in larger families had a lower average IQ than people in smaller families. As data already existed from 1932, it made sense to gather more data. On June 4th 1947, children were given the same test as was used in 1932. 70,805 out of 75,211 born in 1936 were tested. For this group a wide range of data was collected including information on intelligence, school attended, attendance at school and family details. "The SMS 1947 provides arguably the most comprehensive availabe data showing that children from larger families have lower mean IQ scores."