Children learn their place in the world at a very early stage
Inequality in the Early Cognitive Development of British Children in the 1970 Cohort Author(s): Leon Feinstein Source: Economica, New Series, Vol. 70, No. 277 (Feb., 2003), pp. 73-97
This graph shows that children from well off parents who score poorly on a range of tests at 22 months old improve their scores as time goes on. The scores of children of poor parents who did well before they were two years old steadily deteriorate.
Deprivation and Education
The influence of deprivation on educational attainment at the age of 16 is shown very clearly here
and of course it is not only educational attainment that is affected by deprivation
This data is from the 1958 birth cohort study