Example: there are some persons who start from a subject and evolve in a rather chaotic way to other subjects so that the main subject is sometimes forgotten. Another parameter of a personality is associated with the fact that, although the structure of models has to be stable, the structure must be compatible with some models imposed from outside, by education. Without some main models imposed from outside (by education), a human being will be not compatible with the external reality. By education, some models must be present in any brain (some of them must be in the PSM). Any human being is able to integrate into society, based on them. There are now very big problems associated with education, in the present human society. The main problem is the fact that the society (including in most advanced countries) is evolving very fast based on symbolic models and the education is not able to keep the pace with this fast evolution. E.g. the usual method of education is to impose some story-type model (i.e. some models of "how to do"-type). This method has increased too much the number of models that must be stored by the brain and the brain is not capable anymore to store and use all of them. Based on MDT, the normal solution should be to store some normal models that can be tailored by each person to any specific situation. Another parameter is associated with the tendency to think and act based on long-range models or short-range models. Some persons behave based on a number of long-range concept models (principles) which are used in any situation. Other persons have specific short-range models for any specific external reality. The personality parameter is typically situated between the two limits mentioned above. From the general theory, we know that some models generate knowledge and others are used to modify the external reality. Thus, there are personalities oriented mostly to knowledge and others are oriented mostly to change the external reality. There are persons who assimilate easily external models and others who prefer to make their own models. Also, there are image models and symbolic models. We can make a partial matrix associated with a personality based on the capacity to make/assimilate image/symbolic models, for instance.