`  The title of this article is misleading. There are many systems of psychological types. The Jungian Myers-Briggs types have been ballyhooed to the point where references to this single (rather unscientific) typology have swamped references to various other interesting typological systems, including the ancient ``planetary``/temperamental types from which were derived words like ``mercurial,`` ``martial,`` ``jovial,`` etc., Sheldon's somatotypes, David Shapiro's ``neurotic styles,`` etc. This would be all right as a subsection of the Jung article but there should be a more general article on psychological types and the search string ``psychological types`` should return a pointer to that article, not this one, as the first hit.  `