Equilibriation is a mechanism in the cognitive development theory of Jean Piaget. Basically, the idea behind equilibriation is that a child or adolescent constantly imports new information, and often reaches a point where two pieces of information are in direct conflict within a schema. However, the child will eventually resolve this conflict through assimilation of new information in place of faulty information, or through the accommodation of both pieces of information in an adjusted form.

To give you an example of how this works, a fairly recent survey of Harvard University graduates and faculty revealed that the vast majority did not know what caused the earth's seasons. Very few respondents answered "axial tilt," and even fewer could correctly explain why axial tilt caused the seasons. Most of the respondents said that seasons were caused by the Earth's elliptical orbit: strange, considering that the Earth's orbit is almost perfectly circular. It was later postulated that they had this belief because of perspective drawings in earth science textbooks, which show the Earth's orbit as oblong: these pictures melded with factual information to create an inaccurate conception of reality. In short, the students equilibriated the images with their textbook knowledge.

Children experience equilibriation as early as infancy. In the pre-concrete operational stage, for instance, a child often believes that the amount of a liquid changes when it is poured into a differently-shaped container (a test tube versus a beaker, for instance). If the child begins to wonder where the extra liquid comes from (or goes), they re-evaluate their understanding by postulating their own answers or finding external answers, which will also be continuously re-equilibriated over time.

For the counterpoint, see Lev Vygotsky's theory of social constructivism.