Internal and external world and Quadras
This is an argument for Gammas having the greatest distinction between their inner world and the outside, and Alphas making them interact the most.
NF (iNtuition + Feeling) IMEs are the internal ones and ST (Sensation + Thinking) IMEs are the external ones. This can be explained from a subject/object dichotomy. Thoughts and feelings (iNtuition + Feeling) are necessarily generated inside a person's mind, while space and logical laws (Sensation + Thinking) exist in the world itself and would exist even if it wasn't inhabited by humans. It must be kept into account that Intuition in Socionics is more related to thoughts than Thinking (or Logic), which has more to do with understanding systems and processes.
This makes Fi and Ni (internal + introverted) the most internal IMEs out of all, and Te and Se (external + extraverted) the most external ones. Fi creates emotions that stay inside a person's mind and obviously condition their behavior, but are not directly externalized. Ni generates thoughts that stay inside one's mind so they can be further analyzed and are usually not shared, it doesn't foster information exchange. Te understands and manipulates logic and processes without commiting to any of the laws or techniques used. Se acts and moves inside the space, modifying it regardless of what sensations this space brings back to the individual.
Fe, Ne (internal + extraverted), Ti and Si (external + introverted) are in the middle. Fe emotions are generated inside one's mind, but they're externalized and used to create emotions in others, while its effect inside the original person's mind is less permanent than Fi's. Ne ideas are also internally generated, but Ne disposes the individual towards information exchange, and ideas are quickly abandoned in favour of others, unlike the case of Ni. Ti takes a determined set of rules from the outer world and brings them inside to reflect deeply about them and either commit to or manipulate them, while ignoring how other information could be useful in given contexts, unlike Te which can use anything superficially. Si interacts with space to acquire desired sensations, which impact on the individual, and ignores how the individual could impact on reality if there's not an immediate pleasant sensorial feedback, unlike Se.
Alpha is the most open and easy-going, but also passive, Quadra, while Gamma is the most secretive and also the most hard-working and ready-to-act one in general terms. This can obviously be deducted just from looking at valued IMEs, but it's also a consequence of Alpha having the smallest division between the internal and external worlds, and Gamma having the biggest one.
What a Gamma feels and imagines is preferably kept inside if possible due to valued FiNi. Continuity of feelings and lines of thought is sought, with no intention to externalize them. Gammas value stable and deep personal relationships and show little emotional expression (Fi over Fe). They also value foresight and preparation, often do not reveal their intentions and hide information, and are not very curious (Ni over Ne). On the other hand, they desire to modify at their will both objects' movements and shapes due to valued TeSe, which makes them very connected to "the way things work" and show high professionalism and accountability, but these actions are only output. They don't want to commit to any system that they've mastered, because they're considered as tools (Te over Ti), and they don't expect to find peace and inner comfort from the material world (Se over Si). Thus, what is born inside remains inside, and what is born outside remains outside.
Alphas are the opposite: they need to externalize everything they create and internalize everything they receive in order to feel satisfied with it. Freedom of expression is the most important Alpha value, because, due to valued FeNe, they have a need to share their emotions (Fe over Fi) and ideas (Ne over Ni) and make them move as freely as possible. For this reason, Alphas experience a big sense of emptiness if their emotions and proposals (even if just theoretical) are not welcome. Conversely, they bear no desire to change the external world; instead, they want to understand and experience it, which makes them very calm, open and unambitious. Due to valued TiSi, knowledge from the objective world is only valued in relation to other knowledge and as a set of valuable ideas to maintain, never as a situationally useful tool (Ti over Te), while interaction with space and objects must influence the individual positively, not leave a mark on the space or the object (Si over Se). The individual opens their mind and lets the external world influence them simultaneously, and is not interested in anything that is isolated in either the external or the internal realm.
Beta and Delta basically have one axis of each: intuition and sensation are kept in their "natural place" in Betas and inversed in Deltas, while the opposite is true for ethics and logic.