"Each problem that I solved became a rule, which served afterwards to solve other problems."
INTPs are quiet, unobtrusive individuals who like to observe and theorize. They tend to be systematic thinkers and seek to organize their thoughts and observations according to an internal and impartial model of how things work. INTPs are inclined to think in a very logical, almost robot-like manner and are often adept at defining things abstractly as well as pinpointing how each theory or abstraction is logically different or similar to another theory or abstraction. They also seek to understand what goes on around them in a somewhat detached manner where they are more interested in understanding how things work than in how they could personally stand to gain from the theories and things that are currently under scrutiny.
INTPs tend to have a lot of solitary habits and hobbies. They enjoy learning new things, but typically prefer to do so by themselves and in an eclectic manner where they are free to read and think and explore their fields of interest without a preconceived structure imposed on them from the outside.
While they are primarily analytical, many INTPs are also quite imaginative, with a creativity that is often expressed with regard to intellectual matters. They start off by analyzing abstract ideas but then tend to take those ideas in unexpected or offbeat directions. They often do this by extending the principles governing a given idea to the furthest possible extent, even though their ruminations on a given topic have long since left the plane of anything that has been factually established or actually tried.
Though their default demeanor can often be quite demure, most INTPs also have a humorous side, and many are quick-witted when prompted. Often their humor will revolve around their applying stringent and logically valid extrapolations to suppositions that are obviously outlandish or silly. Likewise, they are often good at seeing the humorous absurdity in how societal processes or the governance of large organizations tends to create over-complex and almost self-defeating solutions to problems that (at least on paper) are quite easy to solve.
As opposed to their ENTP cousins, most INTPs are not naturally rebellious or nonconformist. On the other hand, most INTPs dislike bureaucracy and rules which they perceive as having little logic or purpose behind them. Under such conditions, INTPs may find themselves pushing back against conformity or what they see as silly rules, though typically in a more subdued and quiet fashion than is the case with the ENTP, who tends to be more confrontational and outspoken.
In social settings, INTPs are often quiet at first, tending to enter into group discussions only very slowly. On the other hand, they can quickly become engaged and animated if the topic is one that connects to their interests and can be fruitfully analyzed via their logical and “mechanical” mode of thinking. While they can be demure, there tends to be a warm (if unspoken) character to their demeanor, where they come across as intellectually oriented without being haughty or posh. INTPs are often very knowledgeable about the abstract topics that interest them, and if another person takes an interest in these fields the INTP will happily share their knowledge and discuss the topic with them in a humble and straightforward manner.
Most INTPs are creatures of habit. They tend to value a stable environment where things are taken care of for them, so that they are left free to observe, speculate, and explore as they see fit. In interpersonal affairs, the flip side of this preference sometimes means that many INTPs tend to distance themselves from people who place practical or exacting demands on them – even if such demands are sometimes entirely reasonable. While most INTPs are good-natured, they also tend to find the demands of others taxing and are often prone to missing emotional cues or expressions, which can cause them to come across as uncaring or distant.
INTPs are predominantly oriented towards impersonal logic, and the side of them that processes personal relations and emotions is often harder for them to deploy. For this reason, they can sometimes be slow to make lasting friends, and tend to value loyalty and predictability in their relations. Indeed, many INTPs have a hard time dealing with changing relationships, and may retain friends or partners long beyond the point where they should have moved on.
While the thinking of INTPs is primarily logical, a lot of their social preferences tend to revolve around harmony. This goes for their personal lives, as we have just seen, but also extends to the way they think about society and human relations as a whole. Many INTPs carry an unspoken assumption within them that everyone should ideally make decisions according to logical principles and frameworks in the same way that the INTP does, and that if only people could be brought to see things in this way, a great deal of conflict could be avoided.