Phase transitions?
Right, it works for a bunch of specific instances of this phenomenon, but how do you construct a model which describes both phase transitions and human learning (and a host of other similar effects in totally dissimilar substrates)?
Related to: What Do We Mean By "Rationality?"
Rationality has many facets, both relatively simple and quite complex. As a result, it can often be hard to determine what aspects of rationality you should or shouldn't stress.
An extremely basic and abstract model of how rationality works might look a little something like this: