http://similarminds.com/jung/intj.html

INTJ

loner, more interested in intellectual pursuits than relationships or family, not very altruistic, not very complimentary, would rather be friendless than jobless, observer, values solitude, perfectionist, detached, private, not much fun, hidden, skeptical, does not tend to like most people, socially uncomfortable, not physically affectionate, unhappy, does not talk about feelings, hard to impress, analytical, likes esoteric things, tends to be pessimistic, not spontaneous, prone to discontentment, guarded, does not think they are weird but others do, responsible, can be insensitive or ambivalent to the misfortunes of others, orderly, clean, organized, familiar with darkside, tends not to value organized religion, suspicious of others, can be lonely, rarely shows anger, punctual, finisher, prepared

*the descriptions listed here are made up of personality items. people who scored high on this type scored higher on the above items compared to the average. (more info)
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favored careers:

scientist, dictator, forensic anthropologist, systems analyst, philosopher, nuclear engineer, political analyst, researcher, statistician, scholar, research scientist, computer scientist, software designer, curator, computer programmer, aerospace engineer, electrical engineer, paleontologist, english professor, philosophy professor, chemical engineer, epidemiologist, forensic scientist, museum curator, research assistant, mechanic, astronomer, figher pilot, librarian, systems administrator, neurosurgeon, book editor, biotechnology, archeologist, lab tech, bookstore owner

disfavored careers:

advertising executive, job in entertainment industry, performer, singer, art therapist, childcare worker, bartender, dj, even coordinator, hair dresser, wedding planner

These aren't written in stone - some adjectives may apply - some may not apply.

It's just a generalization of the personality type.

http://similarminds.com/jung/intj.html

*Jung types are based on the Myers-Briggs typology