The idea of teaching rationality to kids was behind my posts http://lesswrong.com/r/discussion/lw/iha/raising_numerate_children/ and http://lesswrong.com/lw/ihs/bed_time_stories_with_clear_concepts/ and I plan some more (see also my LW home).

You teach rationality by always answering inquisitive questions truthfully, at their zone of proximal development (http://en.wikipedia.org/wiki/Zone_of_proximal_development ) and no further than they are interested. By providing experiences that trigger such questions (experiments, trips) and by providing lots of books lying around everywhere (hey, even my two year old 'reads' more (picture) books than playing with bricks and he starts getting interested into letters asking for their sound).