Objective: Secondary education has lifelong implications for well-being. We evaluated associations between the timing and duration of low socioeconomic status (SES) during childhood and academic achievement in secondary school.
Methods: Cohort design. The structured modeling approach was used to evaluate life-course models for associations between the duration and timing of low SES (across ages 4–5, 6–7, 8–9, 10–11 years) and Grade 7 (median age 12.5 years) reading and numeracy achievement. Linear regressions were fitted for 4 critical period models (each including low SES at 1 age), 1 sensitive period model (including low SES at all ages), and 2 strict accumulation models (including low SES duration in linear/categorical form).
Results: Of 3734 children, 1718 (46.1%), 1749 (48.6%), 1797 (49.3%), and 1779 (49.8%) experienced low SES at 4 to 5, 6 to 7, 8 to 9, and 10 to 11 years, respectively. For reading, the sensitive period model fitted best. Reading z-score coefficients for low SES (reference: high SES) at 4 to 5, 6 to 7, 8 to 9, and 10 to 11 years were: −0.20, −0.18, −0.02, and −0.22. For numeracy, the categorical strict accumulation model, with SES-by-sex interaction, fitted best. Numeracy z-score coefficients for 1, 2, 3, and 4 periods of low SES (reference: 0 periods) were: −0.38, −0.42, −0.54, and −0.77 for boys, and −0.23, −0.34, −0.42, and −0.54 for girls.
Conclusions: Low SES at all ages studied except 8 to 9 years has cumulative associations with poorer Grade 7 reading. Longer duration of low SES from 4 to 11 years is associated with poorer Grade 7 numeracy, with stronger associations for boys than girls. Academic interventions should be targeted toward children with persistently low SES.