Have you ever wondered what it takes to be President? Obviously having some smarts is top of the list, but how smart? Intelligent quotient (IQ) testing was developed in the early 1900s to assess and measure a person’s level of “intelligence”. IQ tests vary on what they measure. Results can also change with age and over a person’s lifetime. However, generally speaking, the higher your IQ is, the more you are deemed capable and competent!
In 2006, Dean Simonton of the University of California published the results of a study estimating the IQs of previous Presidents of the United States. We’ve included some of these here in our list of the most intelligent presidents. We’ve also included the two most recent presidents, along with their educational and professional backgrounds that hint at having high IQs.
1. John Adams
John Adams, 2nd President of the United States, served from 1797-1801. Adams had an estimated IQ of 155. His son, John Quincy Adams, the 6th President of the United States, had an estimated IQ of 175. Both father and son received their education at Harvard and practiced as lawyers. John Quincy Adams became affiliated with various political parties during his career, spoke several languages and was an avid journal keeper.
2. Chester Arthur
Chester Alan Arthur, the 21st President of the United States, held office from 1881-1885. Arthur had an estimated IQ of 152.3. A graduate of Union College, Arthur worked as a teacher and practiced law. He served in the military as a quartermaster during the American Civil War. Following the war, he became Collector of the Port of New York.
3. George H W Bush
George Herbert Walker Bush, the 41st President of the United States, served from 1989-1993. He has an estimated IQ of 143. Bush initially enlisted in the armed forces at aged 18. He later attended Yale University, graduating with a degree in economics. He then entered the oil industry and political arena. Bush has received several honorary degrees and held many high-level appointments.
4. George W Bush
George Walker Bush, the 43rd President of the United States, held office from 2001 to 2009. He has an estimated IQ of 138.5. Bush holds a degree in history from Yale University and an MBA from Harvard Business School. Like his father, Bush Jr. pursued a career in the oil industry alongside politics.
5. Jimmy Carter
James Earl Carter Jr was the 39th President of the United States from 1977-1981. Carter has an estimated IQ of 156.8. Entrepreneurial from a young age, as a teenager Jimmy Carter grew and sold his own peanuts from his own land on the family farm. Carter graduated with a bachelors degree in Science from the United States Naval Academy. He received a Nobel Peace Prize in 2002 for his contribution to international human rights and democracy.
6. Grover Cleveland
Stephen Grover Cleveland was the 22nd and 24th President of the United States. He held office twice, first from 1885-1889 and then again from 1893-1897. Cleveland had an estimated IQ of 144. In Cleveland’s earlier career, he was a mercantile apprentice, a teacher at the New York Institute for the Blind, and a clerk before becoming a lawyer. He entered politics initially as a Sheriff. Cleveland was then an elected Mayor and Governor before becoming president.
7. Bill Clinton
William Jefferson Clinton, the 42nd President of the United States, held the position from 1993-2001. Bill Clinton has an estimated IQ of 159. Clinton attended Georgetown University, Oxford University, and Yale University Law School. He has also received honorary degrees from other academic institutions. A keen saxophone player, Clinton is also said to have considered a career in music. He also contemplated studying medicine before settling on law and politics.
8. Dwight D Eisenhower
Dwight David Eisenhower, aka Ike, the 34th President of the United States, served from 1953-1961. His estimated IQ was 145.1. Eisenhower attended West Point Military Academy and followed a military career, becoming a General of the Army in World War II. After that he held positions as President of Columbia University and was Supreme Commander at NATO before running for president.
9. Millard Fillmore
Millard Fillmore, the 13th President of the United States, held office from 1850-1853. Fillmore had an estimated IQ of 149. Born into a farming family, Fillmore was initially an apprentice cloth dresser in the woolen industry. Fillmore went on to work as a lawyer before entering politics.
10. Gerald Ford
Gerald Rudolph Ford, the 38th President of the United States, held office from 1974-1977. He had an estimated IQ of 140.4. Born Leslie Lynch King, Ford was later called the full name of his mother’s second husband. Ford attended the University of Michigan, graduating with a degree in economics and a reputation as a football player. He then attended Yale Law School. Ford became a Navy officer and educator during World War II. He was a member of the House of Representatives for 25 years before becoming president.
11. James Garfield
James Abram Garfield was the 20th President of the United States in 1881. Garfield had an estimated IQ of 152.3. Garfield’s father died while he was young, and he initially worked in manual jobs before pursuing a formal education. He then worked as a teacher at various education institutions before moving on to law, a military career, and then a political career. Garfield served only around six months before his assassination.
12. Benjamin Harrison
Benjamin Harrison, the 23rd President of the United States, served from 1889-1993. His IQ was estimated at 145.4. Harrison was the grandson of the 9th President, William Henry Harrison, and the son of a US Congressman. Harrison graduated from Miami University and practiced law before entering politics.
13. William Henry Harrison
William Henry Harrison, the 9th President of the United States for a short period in 1841. Harrison had an estimated IQ of 146.3. Harrison received private tutoring as a child, before attending Hampden-Sydney College. He then attended the University of Pennsylvania and studied medicine briefly. Harrison then embarked on a military career. Along with a political career, Harrison also had farming, equestrian, and business interests. He died in office, just 31 days into his presidential term.
14. Rutherford B Hayes
Rutherford Birchard Hayes, the 19th President of the United States, served from 1877 to 1881. Hayes had an IQ estimated at 146.3. Educated in public schools, Hayes then completed degrees at Kenyon College and Harvard Law School. He practiced law before embarking on a military and then political career. His wife Lucy, was the first wife of a President to hold a degree.
15. Herbert Hoover
Herbert Clark Hoover, the 31st President of the United States, held office from 1929-1933. His estimated IQ was 141.6. Hoover initially worked in a clerical role in an uncle’s real estate business. He supported himself through his degree in geology at Stanford University and became a mining engineer and consultant. His entry into the political arena began with humanitarian work during World War I. He ran for president after the war.
16. Thomas Jefferson
Thomas Jefferson, the 3rd President of the United States, held office from 1801-1809. Jefferson had an estimated IQ of 160. Jefferson was a graduate of the College of William and Mary in Virginia. He practiced law and was also a plantation owner. Jefferson was the main author of the Declaration of Independence. He was also a president of the Philosophical Society, able to speak several languages and an inventor and innovator.
17. John Kennedy
John Fitzgerald Kennedy, the 35th President of the United States, held the position from 1961-1963. Kennedy had an estimated IQ of 159.8. JFK graduated from Harvard University with a bachelors degree in government and international affairs. During World War II he commanded patrol boats for the US Navy. Aged 43 when elected as president, JFK was assassinated a couple of years later.
18. Abraham Lincoln
Abraham Lincoln, the 16th President of the United States, served from 1861 to 1865. Lincoln had an estimated IQ of 150. Lincoln was mostly self-educated. He worked in laboring roles, then as a business owner, postmaster, and surveyor, before becoming a lawyer. As the US President during the American Civil War, Lincoln was instrumental in the abolishment of slavery in the southern States of the US. Lincoln’s assassination was during his second term in office.
19. James Madison
James Madison Jr, the 4th President of the United States, held office from 1809-1817. Madison had an estimated IQ of 160. He studied history, science, politics, philosophy, and law at Princeton University. Madison was instrumental in the ratification of the Constitution of the United States and the drafting of the Bill of Rights.
20. William McKinley
William McKinley, the 25th President of the United States, served from 1987 and 1901. His estimated IQ was 143.4. Initially a postal clerk and then a teacher, McKinley enlisted in the Civil War as a soldier, rising to the rank of Brevet Major. He then became a lawyer and entered politics. McKinley’s assassination occurred soon into his second term in office.
21. Richard Nixon
Richard Milhous Nixon, the 37th President of the United States, held office from 1969-1974. His estimated IQ was 142.9. Nixon attended Whittier College and Duke University School of Law under a scholarship. He practiced as a commercial lawyer, before joining the Navy. In the Navy, he was promoted to the rank of Commander. He resigned from office following the Watergate scandal.
22. Barack Obama
Barack Hussein Obama was the 44th President of the United States from 2009-2017. Obama is a graduate of Columbia University and the Harvard Law School, and a former president of the Harvard Law Review. Obama also worked as a civil rights attorney and university professor before entering politics. He received a Nobel Peace Prize in 2009 for his contribution to international diplomacy and cooperation.
23. Franklin Pierce
Franklin Pierce was the 14th President of the United States from 1853-1857. Pierce had an estimated IQ of 147.4. He studied at Bowdoin College and then entered law and politics. During the Mexican-American War, Pierce achieved the rank of Brigadier General. He was also awarded honorary doctorates from two universities.
24. James K Polk
James Knox Polk, the 11th President of the United States, held office from 1845-1849. He had an estimated IQ of 143.4. Born into a plantation-owning political family, Polk attended the University of North Carolina, graduating with honors. He continued into law and a career in politics.
25. Ronald Reagan
Ronald Wilson Regan, the 40th President of the United States, served from 1981-1989. His IQ was estimated to be 141.9. Reagan was a radio sports announcer, actor, and motivational speaker before moving into politics. Governor of California in the 1960s, he won the election for president on his third campaign, winning 46 of 50 States.
26. Franklin D Roosevelt
Franklin Delano Roosevelt, the 32nd President of the United States, held office from 1933 to 1945. Franklin Roosevelt had an estimated IQ of 150.5. Roosevelt studied economics and history at Harvard and law at Columbia Law School. A fifth cousin of the 26th President, Theodore Roosevelt, FDR entered politics in his late 20s. He served four terms as President.
27. Theodore Roosevelt
Theodore Roosevelt, the 26th President of the United States, served from 1901-1909. Teddy Roosevelt had an estimated IQ of 153. Roosevelt was the first person appointed to the position of US president at 43 years of age. A graduate of Harvard University, Roosevelt also spent time as a rancher and writer. He won a Nobel Peace Prize in 1906 for his mediation efforts in the Russo-Japanese War.
28. Donald Trump
Donald John Trump became the 45th President of the United States in 2017. Trump is the first president to have entered the presidency as a billionaire. His wealth being derived from prior business interests. At 70 years of age, he is also the oldest elected president. Trump attended the New York Military Academy, Fordham University and the University of Pennsylvania in the 1960s. He graduated with a bachelors degree in economics.
29. John Tyler
John Tyler, the 10th President of the United States, held office from 1841 to 1845. Tyler had an estimated IQ of 148.1. He attended the College of William and Mary and became admitted to the bar in Virginia at the age of 19. His succession to the presidential role was from that of Vice President following the death of his predecessor.
30. Martin Van Buren
Martin Van Buren, the 8th President of the United States, held office from 1837 to 1841. Van Buren has an estimated IQ of 146. The son of an innkeeper, he received his initial education at the local village school. Van Buren grew up bilingual, speaking both Dutch and English. He received further education at the Kinderhook Academy and Washington Seminary before entering the law profession, and then politics.
31. Woodrow Wilson
Woodrow Wilson, the 28th President of the United States, served from 1913-1921. Wilson had an estimated IQ 155.2. Wilson obtained a Ph.D. in political science from John Hopkins University and initially pursued an academic career, becoming the President of Princeton University.
32. George Washington
George Washington, the 1st President of the United States, held office from 1789-1797. Washington had an estimated IQ of 140. A descendant of the British gentry, Washington was instrumental in America’s fight for independence from Britain. Washington worked as a planter, land surveyor and in the military as a Lieutenant Colonel before becoming the nation’s first president.