I tend to take charge in group situations, too. I really think it's Fe that does this, believe it or not. I care passionately about the issue at hand, and I read group dynamics really well, so it's very easy for me to take over in a group -- so easy, in fact that I have to tell myself to put the brakes on and give other people a chance. I'll also point out that while Keirsey is quite fixated, if you will, on the gap between F and T, regular Myers-Briggs places much less emphasis on it. There's a comparison in Gifts Differing of two naval officers (if I recall correctly) an INFJ and an INTJ, and the only significant difference seems to be that INFJ is more personable and relates more easily to those under his command, but the emphasis in the comparison is clearly on how similar the two types are.