The cognitive developmental cascade at different timescales: Relationships among intrasubject variability, processing speed, working memory, and fluid intelligence in children aged 8 to 14 years.

were observed at the level of between-person differences on a long-term timescale alongside no evidence of the expected associations of within-person changes for a time frame of 2.5 years. Thus, associations consistent with the developmental cascade model may reflect stable between-person differences rather than short-term within-person changes. This has important implications for developmental theory and methodology. (PsycInfo Database Record (c) 2026 APA, all rights reserved).