Curiously, participants in discussions of all of these subjects seem equally confident, regardless of the field's distance from experimental acquisition of reliable knowledge.

As someone in academic sociology, this conflicts with my experience. Seeming confident is a matter of social skills, temperament, and the conditions of winning arguments with peers in the same area. But as best I can tell, in terms of assigning probabilities, sociologists can be divided into those who think the field (or at least the parts they're engaged in) to be scientific in the same manner as the physical sciences are scientific, but much harder and with greatly reduced ability to assure confidence in its findings, and a minority who think that society is so complex (especially when "meta" epistemological factors are brought in) that confidence in any of its conclusions beyond dumb facts is unwarranted and that science is a bad term for it. Claims people state with great confidence tend to be ones that enjoy broad agreement.