Cognitive capacity, expression, and compensability
Cognitive Capacity, Expression, and Compensability
This page explains the distinction between cognitive capacity and cognitive expression, and how this distinction becomes visible within structured domain-based assessment such as WAIS.
Cognitive capacity refers to underlying reasoning ability — abstraction, conceptual integration, and problem-solving. Within WAIS, this is most strongly reflected in reasoning-dominant domains such as Verbal Comprehension (VCI) and Perceptual Reasoning (PRI).
Cognitive expression refers to the conditions under which capacity can be accessed and demonstrated. Within WAIS, efficiency-dominant domains such as Working Memory (WMI) and Processing Speed (PSI) strongly influence access to capacity under load.
Where these domains diverge significantly, performance may reflect limits of access rather than limits of capacity.
Capacity versus expression
Capacity describes what an individual is able to reason or understand in principle.
Expression describes how effectively that reasoning can be deployed under specific conditions — such as time pressure, memory load, sequencing demands, or format constraints.
A limitation in expression does not imply absence of capacity.
Compensability in principle
A cognitive difference is compensable in principle where underlying capacity is present but access to that capacity is constrained by working memory, processing speed, or other efficiency demands.
A cognitive difference is not compensable where intrinsic reasoning capacity itself is limited.
This distinction is structural and does not depend on effort or motivation.
Relationship to WAIS domain structure
WAIS domain separation makes this distinction measurable. Significant discrepancy between reasoning-dominant and efficiency-dominant indices provides empirical indication of uneven cognitive architecture.
The broader framework described in this section derives from that observable structure.
Related pages
WAIS Domain Structure and Internal Discrepancy
Uneven Cognitive Profiles Explained
Why Generic Assessment Fails with Uneven Cognitive Profiles
