I don't know if there has already been a thread on this but i thought it'd be fun to think of who would be the most compassionate thinker of all T types. And when I say 'compassionate' I mean most likely to take in consideration the feelings of others.
First of all I would say the **TJ function because they make very good managers, being very descisive and managers have to take into account the feelings of their workers. I would narrow it down to *STJ's because they are more personable then I would say, due to ESTJ's having a slightly hostile attitude at times the ISTJ would be most considerate of others. Especially their friends. They are also quite naive about the darkness out there.
Special mention also goes to the ESTP who, although they are forward, blunt and assertive alot of the time they only like to have a good time and be socialable and do not set out to hurt people in any way. Not unless they are given reason to.
Most inconsiderate of even 'ruthless' feeling type would have to be an **FP type. Because although they are feeling types, they are more concentrated on their own happiness and enjoyment alot of the time.
After that I am torn between the ESFP and the ENFP. I feel introverted types are somewhat more compassionate because they have more time to process other people and feelings rather than being set to 'GO' at all times like more extraverted types. I feel the ESFP is more focused on having fun while the ENFP is more focused on hyping/motivating causes. I would think the ESFP would be the least compassionate. Although I wouldn't call them 'ruthless'. Perhaps they are ruthless in their pursuit of fun however and become rude if they cannot have it.