| IQ | PRESIDENT | PARTY |
| 182 | William Jefferson Clinton | [D] |
| 175 | James Earle Carter | [D] |
| 174 | John Fitzgerald Kennedy | [D] |
| 155 | Richard Milhous Nixon | [R] |
| 147 | Franklin Delano Roosevelt | [D] |
| 132 | Harry S Truman | [D] |
| 126 | Lyndon Baines Johnson | [D] |
| 122 | Dwight David Eisenhower | [R] |
| 121 | Gerald R. Ford | [R] |
| 105 | Ronald Wilson Reagan | [R] |
| 098 | George Herbert Walker Bush | [R] |
| 091 | George Walker Bush | [R] |
The six Republican presidents of the past 50 years had an average IQ of 115.5, with President Nixon having the highest at 155. President George W. Bush rated the lowest of all the Republicans with an IQ of 91.
The six Democratic presidents of the past 50 years had an average IQ of 156, with President Clinton having the highest IQ, at 182. President Lyndon B. Johnson was rated the lowest of all the Democrats with an IQ of 126. No president other than Carter [D] has released his actual IQ (176). Note the institute measured him at 175. LINK