NAPLAN: IQ versus poverty

THE release of NAPLAN data ­always brings some sort of controversy. This year it was about a ­decline in writing performance, but a longer running controversy is the persistent gap in literacy and numeracy associated with socioeconomic status.

New research by Gary Marks, published in the Australian Journal of Education, finds that student achievement in the National Assessment Program — Literacy and Numeracy had a very weak relationship with SES, once prior achievement and school differences are taken into account. By far the strongest predictor of Year 5 and Year 7 NAPLAN scores was Year 3 ­NAPLAN scores; SES and school factors were relatively weak predictors. Student achievement in all of the NAPLAN domains was also highly correlated suggesting tests measure general ability.

This research supports other extensive research by Marks showing that cognitive ability (or IQ) is the single biggest influence on student achievement. It trumps socioeconomic status and school factors, including teacher quality. But this does not mean that socioeconomic status is irrelevant. It is clear to even casual observers that children from low SES backgrounds are at a higher risk of educational disadvantage than their higher SES peers. The question is when this disadvantage emerges and how. Marks suggests the impact of ­social inequalities on student achievement may have its roots earlier in the education and child development cycle than Year 3.

SES may not be the strongest predictor of achievement but, unlike cognitive ability, it is a factor that policy affects. To reduce the influence of SES on student achievement, we have to understand the relationship. Persistent poverty is implicated, and low parental education plays a part, but an important set of research findings on SES and literacy shows the relationship between socioeconomic disadvantage and low achievement is most strongly predicted by non-financial characteristics associated with low SES families.

Early language and literacy ­acquisition make a major contribution to later school achievement, and are influenced by genetic and environmental risk factors. Children in low-SES families are at higher risk of cognitive deficits from preterm birth and low birth weight. Children growing up in low-SES families are less likely to have homes that instil alphabetic and print knowledge and cultivate oral language skills such as vocabulary. Low-SES children are less likely to attend good preschools.

The effects of these characteristics and experiences are cumulative and interactive, creating wide language and literacy disparities as early as 18 months and evident on the first day of school.

The bad news is that these gaps usually persist and even grow throughout children’s school lives. At the individual level, low SES is associated with low parental expectations and poor school attendance. At the school level, SES effects are associated with school practices, the quality of teaching, and the school’s academic culture. These effects show up in ways not necessarily measured by NAPLAN or tertiary entrance scores, such as lower rates of school completion.

The good news is that effective initial and remedial literacy instruction and high-quality secondary schooling can mitigate the effect of SES. Children from low-SES backgrounds are the most adversely affected by low-quality instruction, but they benefit most from excellent instruction.

It is true that the correlation between SES and educational outcomes does not prove causation. It is also manifestly true that low SES does not destine a child to poor achievement. Yet the research in this area is building up good evidence of the predictive pathways, showing how these factors accumulate and interact across time to multiply the impact of disadvantage on some children.

Acknowledging that the relationship between SES and educational outcomes is attributable, in part, to other variables, does not negate its effect. Rather, identifying the factors that translate socioeconomic disadvantage into educational disadvantage, and understanding the processes by which they work, is the key to reducing its impact.

Jennifer Buckingham is a research fellow at the Centre for Independent Studies.