ISTJ - The Duty Fulfiller - Serious and quiet, interested in security and peaceful living. Extremely thorough, responsible, and dependable. Well-developed powers of concentration. Usually interested in supporting and promoting traditions and establishments. Well-organized and hard working, they work steadily towards identified goals. They can usually accomplish any task once they have set their mind to it.
ISTP - The Mechanic - Quiet and reserved, interested in how and why things work. Excellent skills with mechanical things. Risk-takers who they live for the moment. Usually interested in and talented at extreme sports. Uncomplicated in their desires. Loyal to their peers and to their internal value systems, but not overly concerned with respecting laws and rules if they get in the way of getting something done. Detached and analytical, they excel at finding solutions to practical problems.
ISFJ - The Nurturer - Quiet, kind, and conscientious. Can be depended on to follow through. Usually puts the needs of others above their own needs. Stable and practical, they value security and traditions. Well-developed sense of space and function. Rich inner world of observations about people. Extremely perceptive of other’s feelings. Interested in serving others.