Longitudinal predictors of self-derivation through memory integration-A mechanism of knowledge accumulation.

Knowledge accumulates through direct instruction and as a consequence of productive memory processes. We report a longitudinal investigation of correlates of the specific productive process of self-derivation through memory integration, targeted because it is a compelling model of accumulation of semantic information. We sampled 148 children aged 8 to 12 years at enrollment. At each of two waves 1 year apart, children were tested on self-derivation through integration and on a battery of potential predictors thereof: cognitive abilities (recall of directly taught facts, verbal comprehension, visualization, visual-auditory learning, and working memory), educational experiences, and family socioeconomic status. Age-related variability was eclipsed by relatively stable individual variability. In both concurrent and longitudinal models, the only significant predictor of self-derivation was recall of directly taught facts. Together with prior research, the results suggest that self-derivation of new knowledge through integration is an individual trait not subsumed by general verbal and spatial skills.