Hossein Jorjani
First publication: 2026 – 06 – 30
Scientific education commonly proceeds by means of simplified models. Because complex systems are difficult to understand in their full generality, instruction often begins with deliberately unrealistic cases that isolate a single principle while suppressing complicating factors. Such models serve an indispensable pedagogical function: they provide the conceptual scaffolding required before more realistic theories can be understood.
The difficulty arises when these introductory models cease to be regarded as didactic approximations and instead become the default conceptual framework through which reality itself is interpreted. What was originally intended as a stepping stone gradually acquires the status of an ontological model. The simplification, initially introduced for the convenience of learning, begins to determine the learner’s intuition long after it has ceased to be scientifically adequate.
Quantitative genetics provides a clear illustration. Most textbooks begin with the genetics of a single locus, proceed to two loci and linkage, and only later introduce the infinitesimal model and the statistical treatment of continuously varying traits. Although this progression is pedagogically natural, many students find the early models considerably more intuitive than the full quantitative theory. As a result, they often continue to interpret quantitative phenomena using intuition developed from single-locus inheritance, even after mastering methods that assume the simultaneous action of thousands of loci. The introductory model remains psychologically dominant despite being biologically exceptional rather than typical.
The same phenomenon appears throughout science. Introductory economics often begins with a representative rational agent before confronting heterogeneous populations and strategic interaction. Elementary mechanics introduces frictionless planes and point masses before addressing dissipative systems and continua. Early atomic theory begins with Bohr’s atom before advancing to quantum mechanics. In each case, the initial model is retained not because it is the most accurate representation of reality, but because it is the easiest to visualize and manipulate.
A comparable concern appears in the social sciences. Georges Gurvitch criticized sociological theories that attempted to explain society by beginning with isolated individuals, arguing that many genuinely social phenomena cannot be reconstructed by simple aggregation. Whether or not one accepts Gurvitch’s conclusions, his criticism illustrates the same methodological principle: the simplest pedagogical unit need not coincide with the most appropriate explanatory unit.
The lesson is therefore methodological rather than disciplinary. Simplified models are essential for learning, but they should not be mistaken for faithful representations of the phenomena they were designed to introduce. Their value lies in facilitating understanding, not in defining reality. Scientific progress often requires recognizing the moment at which conceptual scaffolding must be removed, allowing richer and more complex theoretical structures to replace the simplified models that first made them intelligible.
Hossein Jorjani 