Perhaps Bush's I.Q. was taken before he killed all those brain cells with booze and coke?
I also took several self scoring I.Q. tests with my twin brother, as we thought they were fun and we were competitive. After taking several, and getting higher and higher scores I am of the school of thought that education will increase your scores, e.g., some of the questions can be quickly and easily answered if you've learned how to use venn diagrams -- and one could actually study for an i.Q. test, as all have similar groups of questions. Don't even get me started on the advantages of growing up white and affluent the cultural advantage they afford.