This study aimed to investigate the extent to which WM measured in kindergarten predicts
WM measured in second grade (stability of individual WM progress), and the extent to which
WM measured at kindergarten predicts academic performance at second grade (N = 94). The
results showed that WM skills significantly increase during the time span from Finnish
kindergarten to second grade. Verbal (VWM) and visuospatial WM (VSWM) resources seem
to develop quite independently, whereas individual progress showed some stability. WM
resources measured just before the start of formal school predicted later academic
performance, and VWM acted as more powerful predictor than VSWM resources. The results
have two important educational implications: first, individual or group-based intervention
designed to enhance children’s WM skills would be most important even before the start of
school, and second, poor WM skills should be addressed when planning the learning
environment beginning in kindergarten.