Amidst all of the models and theories of Socionics, and our own evaluations of these models and their merit, there can be a lot of confusion and discord. The one universal constant about Socionics that we can glean from typing threads, for members and celebrities alike, is there is rarely any consensus about a person's type. The inconsistency of the theory results from a lack of empirical evidence for the concepts that are inherent to the foundation of Socionics, and no rigidly defined criteria for determining important typology markers. This, in a nutshell, is why Socionics will probably never be considered for scientific investigation and inquiry. This is not up for debate, it's simply fact.
So I have a challenge I'd like to put to the forum: Define the very idea that is at the core of Socionics. If you had to answer in a single sentence, without making any assumptions or taking anything for granted, what is the basic observation about the natural world that necessitates a theory like Socionics to explain it's underpinnings? Furthermore, how would you conceive an experiment to empirically test that hypothesis? How would you falsify it?
Definitions of terms and relevant concepts: