Table 1

 Correlation coefficients for the relationship of IQ at 7, 9 and 11 years with social and physical characteristics of study participants

IQ at 7 yearsIQ at 9 yearsIQ at 11 years
*Point biserial correlation coefficient.
†Higher scores on these variables indicates greater socioeconomic adversity.
For all correlation coefficients, p<0.001.
Birth weight
Father’s social class in childhood†
Family size in childhood†
Housing tenure in childhood
Car ownership in childhood
Educational attainment
Income in adulthood
Social class in adulthood†
Housing tenure in adulthood
Car ownership in adulthood