Principle 2: Skills are hierarchical, interactive, and dynamic.
Skilled activity is the result of multiple skills collaborating with each other.
Note: Unconstrained Kids unpacks, translates, and integrates academic research and data about constrained and unconstrained skills for people that run, fund, and assist organizations that teach and serve kids. This post is part of a series that describes 14 key principles of skill building I identified from the Science of Learning and Development. (Especially Dynamic Skill Theory.) Like everything on this Substack, this post is a work-in-progress. I will make updates as needed. Citations are included at the end. Questions, comments, and suggestions are welcome.
Last updated: June 4, 2025
Key Takeaway
Skill is the ability to think and act in an organized way in a specific context (Immordino-Yang and Fischer, 2010). Skilled activity is the result of multiple skills collaborating with each other. Skills are organized hierarchically. Lower-level skills support higher, more complex skills. Skills collaborate within and across levels. Skills build together, though some take longer to fully develop than others. The relative contributions of individual skills and groups of skills are not static and change over time.
“As skills become integrated and differentiated at later levels, the component skills subordinate themselves to new forms of organization and mutual regulation. The very process of creating new skills through self-organizing coordination leads to a multileveled hierarchical structuring of living skills.” (Fischer & Bidell, 2006)
Skills organize themselves into multilevel hierarchies. New skills at higher, more complex levels are built from lower-level skills. Skills integrate with each other to create newer, more complex skills. Nonetheless, the component skills within this hierarchy of skills continue to operate as subsystems that can function as standalone skills (Fischer & Bidell, 2006).
For example, the early basic skill of recognizing letters combines with other skills to support more complex skills of phonics, decoding, spelling, word-reading, reading fluency, and reading comprehension. But when needed the basic skill of letter identification can be used on its own.
Skills are highly interactive. They operate in a sort of continuous feedback loop. Skills interrelate and collaborate with each other to support goal-oriented activity. Individual skills and networks of skills directly and indirectly support reading and math achievement (LeFevre et al., 2010; Rittle-Johnson et al., 2017; Hjetland et al., 2019; Kim, 2023).
Some skills contribute by supporting the development and integration of other skills. What we call “executive function” is a group of highly interactive component skills: attention control, attention shifting, inhibition control, and working memory (Dawson & Guare, 2018; Cantor et al., 2019). These skills make key contributions to math- and reading-specific skills such as problem solving, word-reading, and comprehension.
Skills are highly dynamic. Their individual contributions to skilled action change over time. For example, in the early phases of learning to read, word-reading subskills such as letter identification, phonics, and decoding are major drivers of reading achievement.
As children improve reading fluency, the contribution of word-reading skills to reading comprehension decreases relative to other skills (LAARC, 2015; Kim & Wagner, 2015). Researchers find that by fourth grade, other skills such as attention control, working memory, vocabulary, grammar, perspective taking, and listening comprehension support reading comprehension of average readers at a level equal to (or greater) than word-reading skills (Kim, 2020).
But wait, there’s more
Works Cited
Fischer, K. W., & Bidell, T. R. (2006). Dynamic development of action and thought. In R. M. Lerner & W. Damon (Eds.), Handbook of child psychology: Theoretical models of human development (6th ed., pp. 313–399). John Wiley & Sons, Inc.
Hjetland, H. N., Lervåg, A., Lyster, S. A. H., Hagtvet, B. E., Hulme, C., & Melby-Lervåg, M. (2019). Pathways to reading comprehension: A longitudinal study from 4 to 9 years of age. Journal of Educational Psychology, 111(5), 751.
Immordino-Yang, M. H., & Fischer, K. W. (2010). Neuroscience bases of learning. In V. G. Aukrust (Ed.), International encyclopedia of education (3rd Edition, pp. 310–316). Elsevier.
Kim, Y. S. G. (2020). Hierarchical and dynamic relations of language and cognitive skills to reading comprehension: Testing the direct and indirect effects model of reading (DIER). Journal of Educational Psychology, 112(4), 667.
Kim, Y. S. G. (2023). Simplicity meets complexity: Expanding the simple view of reading with the direct and indirect effects model of reading. In S. Q. Cabell, S. B. Neuman, & N. Patton Terry (Eds.), Handbook on the science of early literacy (pp. 9–22). The Guilford Press.
Kim, Y.-S. G., & Wagner, R. K. (2015). Text (Oral) Reading Fluency as a Construct in Reading Development: An Investigation of Its Mediating Role for Children From Grades 1 to 4. Scientific Studies of Reading, 19(3), 224–242.
Language and Reading Research Consortium. (2015). Learning to Read: Should We Keep Things Simple? Reading Research Quarterly, 50(2), 151–169.
LeFevre, J. A., Fast, L., Skwarchuk, S. L., Smith‐Chant, B. L., Bisanz, J., Kamawar, D., & Penner‐Wilger, M. (2010). Pathways to mathematics: Longitudinal predictors of performance. Child Development, 81(6), 1753–1767.
Rittle‐Johnson, B., Fyfe, E. R., Hofer, K. G., & Farran, D. C. (2017). Early math trajectories: Low‐income children’s mathematics knowledge from ages 4 to 11. Child Development, 88(5), 1727–1742.