Michael Commons

The Model of Hierarchical Complexity and Postformal Thought

Michael Lamport Commons (1950 - ) is a pivotal figure in the field of cognitive development, renowned for developing the Model of Hierarchical Complexity (MHC). This model provides a formal, quantitative, and mathematical framework for understanding and measuring developmental stages, extending beyond Piaget’s formal operations into what he terms “postformal” thought. Commons’s contribution offers a rigorous way to assess the complexity of thinking, reasoning, and problem-solving in any domain, arguing that the difficulty of tasks can be objectively measured based on their inherent hierarchical structure.

The core of the MHC is the idea that higher-order actions (or tasks) are defined by the non-arbitrary organization and transformation of actions at the next lower order of hierarchical complexity. This means that to successfully complete a task at a given stage, an individual must first be able to perform and coordinate all the necessary sub-tasks at the immediately preceding stage. This principle allows for a precise, objective measurement of developmental stage, independent of content.

Key aspects of Commons’s contributions include:

The Model of Hierarchical Complexity (MHC): This is his primary contribution. The MHC specifies a sequence of 16 orders of hierarchical complexity (and corresponding stages), ranging from very basic automatic and sensory-motor actions (which can even apply to non-human organisms) to highly advanced forms of human cognition. This model distinguishes itself by:
Quantifying Complexity: It assigns a numerical “order” to tasks based on their mathematical complexity, providing a universal, cross-cultural, and cross-species measure of development.
Task-Based Assessment: It separates the complexity of the task from the complexity of an individual’s performance, allowing for a more objective assessment of developmental stage.
Addressing Postformal Thought: Crucially, the MHC extends well beyond Piaget’s formal operational stage, providing detailed descriptions of four distinct postformal stages:
Systematic: Integrating and coordinating multiple formal systems.
Metasystematic: Reflecting on and comparing multiple systems, identifying their underlying assumptions.
Paradigmatic: Creating new, overarching frameworks (paradigms) that integrate and transcend existing metasystems.
Cross-Paradigmatic: Operating with a unitive understanding that integrates and synthesizes multiple paradigms.
Emphasis on Task Analysis: Commons’s approach is rooted in detailed task analysis, breaking down complex behaviors into their constituent parts and identifying how these parts are hierarchically organized.
A Non-Mentalistic Model: Unlike some other stage theories that focus on internal mental structures or schemas, the MHC primarily characterizes developmental stages in terms of the complexity of the tasks that individuals can successfully perform, observable behavior.

In essence, Michael Commons’s Model of Hierarchical Complexity offers a rigorous, quantitative, and empirically testable framework for understanding the full spectrum of cognitive development, from basic actions to the most advanced forms of thinking, reasoning, and problem-solving seen in profound innovation and wisdom. His work provides a powerful tool for precisely mapping the hierarchical stages of intellectual growth and the mental structures required to navigate increasing complexity.