They start off primary school behind in reading and make significantly less progress by the time they move into secondary. That continues to be the reality for many Aberdeen pupils from disadvantaged areas, whose parents claim clothing grants.
The first study of test scores for a full cohort of primary pupils as they moved from P1-P7 shows that deprivation remains the key factor in how well pupils do at primary. It is a much more significant feature than the differences between boys and girls.
Boys are catching up with girls in reading as they move through primary, the study found, which provides further evidence of how teachers are tailoring classroom approaches to narrow the traditional attainment gap.
A paper presented this week to city councillors on the use of Performance Indicators in Primary Schools (PIPS) tests confirms that pupils who live in relative poverty start P1 with lower average reading and maths scores and make much less progress in both by the end of P7.
The study began in 1998-99 and monitored progress of the cohort through to 2004-05. Aberdeen is regarded as the lead Scottish authority on value-added testing.
The report by Anne Horgan, principal statistical officer, also highlights the difficulties of the many children who did not complete seven years of primary schooling in the city.
Many others moved school, sometimes more than once. Previous reports have commented on the negative effect this can have.
In reading, the detrimental effect of clothing grants on progress had its greatest impact between the start of P1 and the end of P3. The gap was not as wide at the end of P7 as it was at the end of P3.
In maths, clothing grant children started with lower scores and finished with lower scores but the gap had not widened. Similarly, children in disadvantaged areas start with lower average scores and make "significantly less progress" by the end of P7.
Deprivation, Ms Horgan says, has a greater impact on reading than on maths.
"The greatest detrimental effect of deprivation on progress was apparent by primary 3 in reading and by primary 5 in mathematics.
"It is very encouraging that the gap in reading attainment due to deprivation which widened between primary 1 and primary 3 did not worsen further by the end of primary 7," she states.
Differences between girls and boys across the ability range are largely negated by the time pupils leave for secondary. In reading, girls start with higher average scores, continue their progress in middle primary but do not maintain their advantage.
"By the end of primary 7, boys had caught up and there was no significant difference in the average reading scores of boys and girls by the end of primary 7," Ms Horgan says.
In maths, girls and boys start with the same average scores and there is no significant difference by the end of P7.