The influence of age, schooling, literacy, and socioeconomic status on serial-order memory

We aimed at investigating whether formal schooling and literacy favor progress in verbal serial-order short-term memory (STM). In Experiment 1, we presented children varying on age, school level, and socioeconomic background with a serial-order reconstruction task and observed differences related to both age and school level. Two subsequent experiments aimed at separating schooling- and literacy-related effects from age-related ones. In Experiment 2 we compared, on the one hand, performance of children of similar age but different school levels and, on the other hand, performance of children of same school level but different ages. We observed a schooling effect but no age effect on serial-order reconstruction: the youngest first-graders outperformed age-matched kindergartners but performed similarly as older first-graders of the same literacy level. Furthermore, children’s literacy abilities were strongly correlated to their serial-order reconstruction performance, even after controlling for the effects of non-verbal reasoning and vocabulary. In Experiment 3 we examined low socio-economic background adults presenting varying (correlated) levels of schooling and literacy: some had attended school in childhood for only a few years and were either illiterate or very poor readers, whereas others had attended school for at least 12 years. In addition to serial-order memory, item STM was assessed by a delayed single nonword repetition task. The groups differed on both STM tasks, which both correlated with their literacy abilities. Thus, literacy and schooling do not impact only order memory, but more generally verbal STM. Moreover, comparison between the adults’ and children’s data strongly suggests that it is schooling and/or literacy rather than age per se that matters for serial-order memory.