@lecter has touched on another facet a little - assuming that the Reinin dichotomies are reliable. But even not thinking about the Reinin dichotomies, it is clear that someone who is primarily a short-term positivist can be a long-term negativist and that someone who is a positivist in relation to people may be a negativist in other areas. Someone may be upbeat about the people around them but be overwhelmingly negative about the future of humanity etc.