I think Introversion and Extraversion does play a part in 'crankiness', 'whininess', 'outbursts', and 'volatility' but it's more in combination with other cognitive functions.
FWIW, I've always been considered 'easy going' to the point parents of the most problem/unpopular children in the neighborhood would make play dates with my mom because I was the only kid who could stand their kid or vice versa. Whether they were bullies or extremely shy, they would actually find a play mate in me (you're welcome!!!!)
I don't think ENFX would be considered 'cranky' but INFP? ...
I don't think XNTJ would be considered 'cranky' either, but perhaps 'demanding' and not as keen on social niceties which could illicit many 'cranky' and short seeming responses when it comes to getting something done.
The most volatile/surprising outburst folks I've seen in my circle of friends are IT females. INTP/ISTJ This is purely observational.
In these cases, the 'I' makes their internal tolerance of things and responses to things very hidden. You don't know what they are thinking until !BAM! They also don't have the same coping resources (threshold for stimuli, extraverted communication, looking at it from others' POV, 'talking it out')
The funny (to me) thing is that the IT females often get into misunderstandings and spats with one another (look ma, no Es and no NFs!)
So it's not so much an 'I' think as a very rigid J or extremely introverted Fi/Ti IT thing that's not supported by other functions or bolstered by some kind of learned skills or valve or bridge to other people so that situations are curbed and nipped in the bud
before crankiness and outbursts set in.
Basically coping skills.
For chatty 'Es' we have some coping mechanisms built-in -- namely 'talking it out' and being more likley to express ourselves
before the point past frustration. This helps immensely curb any volatile outbursts before it gets to that point. 'Is' built in coping mechanism is having internal frameworks to 'process', but honestly in the realm of human relations the 'E' attempt at communication goes a lot further to dealing with the issue directly.
But, maybe I'm totally off here.
As for whininess, I guess that depends on how it's defined. I think Extroverts are more likely to verbalize their feelings and grumble but it's just words -- at least for me it is. I complain quite easily about things but it doesn't mean much. I have no problem with E's winning the 'whiny' award.
