Have Socio-Economic Inequalities in Childhood Cognitive Test Scores Changed? A Secondary Analysis of Three British Birth Cohorts
Research has consistently demonstrated that there is a relationship between parents' social and economic positions and their children's scores on tests which measure cognitive performance. There are marked social inequalities and children from less advantaged social backgrounds generally perform less well on cognitive tests. Theorists have suggested that children born more recently tend to perform better on cognitive tests than children born in earlier generations. The overall aim of the proposed research is to examine the extent to which the relationship between parents' socio-economic positions and their children's performance on cognitive tests has changed.
The UK is unique because it has a long tradition of collecting data on children and following them into adulthood. These studies are known as birth cohort studies and in the proposed research we will undertake advanced statistical analyses of three of these studies. We will be using data from three birth cohort studies, the National Child Development Study (NCDS) which began in 1958, the British Cohort Study (BCS) which began in 1970, and the Millennium Cohort Study (MCS) which began in 2000.
There are two main research challenges associated with the proposed work. The data in these studies was not primarily collected for making comparisons, and over the course of time there have been changes in how the data are collected and how things are measured. The first challenge is the practical one of constructing a set of measures that are suitably consistent, and that allow genuine comparisons to be made. The second challenge is more statistical. The NCDS and the BCS are older studies and they were collected using a relatively straightforward selection technique, which selected all of the babies born in one week of the year. The MCS has a more complex design. Children are selected because they live in different parts of the UK, and because of the type of area that they were born in. At the same time extra children from areas with high levels of ethnic minority families were also selected. More complex statistical methods are required to analyse data from the MCS. At the current time there is no recognised method for undertaking combined statistical analyses using data from the NCDS and the BCS along with data from the MCS. Providing a solution to this problem is the second challenge. Drawing on advanced statistical thinking we will seek to develop an effective and practicable technique to perform combined statistical analyses of the three datasets. We will also develop resources to help researchers who wish to combine data from the MCS with other studies with complex designs (examples include studies such as Growing up in Australia and Growing up in Scotland).