What do you mean by "ignore cognitive functions", and what would motivate someone to play up their type stereotype? I hear that assertion from time to time, and have always wondered what is behind it.
Well franky the only observable evidence is....just that: observable and in fairness it depends upon who is viewing it. I'm afraid I was being far too certain in my pronouncement.
But an example for me would be, (and this isnt directed at you or anyone here), someone does some useless online test, gets INTJ, read's a misleading title like 'mastermind' and goes "Oh that must be me" without any real understanding of what is behind the description and theory.
Ive seen this on other forums where someone feels obligated to be as offensive as possible because; "I am a thinker". When in reality the reason some thinkers, especially Te ones, come off as offensive to feelers is that a thinker often views things from an impersonal, logical angle and when they appear to be criticising something, they are often just analyzing it without bias, they are looking at flaws but usually not for the use of personal insults. This is often perceived by some feeling types as criticism which leads into some generalised opinions that thinking types take pleasure in casual cruelty.
This then leads into some posts ive seen before I joined here, on other forums, where people were going out of their way to be insultive or hyper-critical without any benefit to those they were criticising, but using the fact that they had a T in their letter as the excuse. And this is just one example. I havn't got into those who feel they have to be fluffy and pleasant just because they have an F in their type letters.
Or perhaps opinions such as: N's are more abstract and intelligent than sensors which is complete shite. I suppose im talking about stereotypes and generalisations. But these lead from misappropriations of the theory in the first place. I also remember a forum I used to go on where a member switched their type from INFP to INTP and suddenly, almost without warning, they started being critical of everything they saw, pointing out flaws and problems, often where there weren't any.
They may have truely had the functional lineup of an INTP, or an INFP, but the point was that once they thought they were that type; they felt influenced to play up to what they obviously perceived as being part of it.
As for the motivation to do this, it's simple; it gives people a bit of grounding and confidence, not knowing your MBTI type is a cause for doubt just like any other uncertainty, people have even talked about this themselves, how, once they believe they have ascertained their type, that they notice themselves becoming more like the description of said type. It is for the same reason that some people gain a great deal of pride from being, (or assuming they are), a rare type, the motivation is personal, there isn't anything tangible to be gained except a bit of self-affirmation and confidence.
The descriptions online dont really mean anything...unless you do have some grasp of the functions of each type and how they work. For example, someone reading an INFP description might believe they see some of themselves in it, but like astrology these descriptions often give such generalised traits that most people can identify with several different types at once. So this same person reading this description does not think of an INFP as Fi-Ne-Si-Te, instead they see the type as:
Generally thoughtful and considerate, INFPs are good listeners and put people at ease. Although they may be reserved in expressing emotion, they have a very deep well of caring and are genuinely interested in understanding people. This sincerity is sensed by others, making the INFP a valued friend and confidante. An INFP can be quite warm with people he or she knows well.
This also might reinforce a sense of doubt if that person does not see themselves matching up entirely with everything or seeing something similar in an INFJ description and doubting themselves, doubt being what is behind these little play acts in the first place.
The important point is that while one type might share certain traits because of their functions, no two types will ever be the same as individuals.
So, essentially, one INFP is not the same as another INFP. The idea is that this theory explains people and how they observe and evaluate the world around them, leading into their interaction with it to the furthering or our understanding of each other. It is not so that people can generalise and stereotype by putting others into boxes.
For myself when I first discovered this theory I did some pointless online test and got INTP...the questions were so vague that it was hard to know what answer would be my own reaction or observation, especially since your most dominant function is often automatic in it's usage. Anyhow I read the description and then read some others...many of them seemed to fit all at the same time, I knew that was a problem in itself, then I ended up going onto the cognitive functions themselves and I actually read up on those and the entire theory itself and Jung's work. Then things actually started to make sense and I was able to work out that there was no way that Ti was my dominant function, it was definitely present, but not so strong as to be dominant. So after months and months of research here I am.
The way I typed online and interacted with others in real life and online, never changed, my views and opinions change all the time of course, but the way they change didn't.
I know this is just anecdotal, but if you want I can go on a little search for evidence to try and prove that this is more than just a cognitive bias on my part. Of course im not sure if im allowed to link other forums.