Small differences between the home lives of children from the “squeezed middle” and those from more affluent families can have a significant impact on their development by the age of five.

A report for the Resolution Foundation thinktank, On Your Marks: measuring the school readiness of children in low to middle income families, found that children from low to middle income families have a vocabulary age that is five months behind their richer peers when they start school.

The authors analysed information about the lives of 15,000 children born in 2000 and found that 75 per cent of children in the high income group were read to daily at the age of three, compared with 62 per cent in the low to middle income group. They say reading to children daily can have a powerful effect on vocabulary.

“Where parents are squeezed for resources of both time and money there is a risk that the resulting stress translates into less conscientious or sensitive parenting,” they conclude.