Intelligence quotient (IQ) is used to measure a person’s level of intelligence. Scores are gathered by participants completing standardised tests that measure abilities in puzzle-solving, memory, and more.
Based on a median score of what’s typically around 100, your given IQ score is relative to that of the general intelligence of the population. Below 85 is seen as a poor score, 130 and above is smart (in the top 2 per cent of the population).
It is difficult to accurately judge intelligence and it’s always worth taking IQ scores with a pinch of salt due to cultural differences and other factors. As a study in Frontiers In Systems Neuroscience states, “intelligence test scores are often misunderstood and can be misused.”
Another factor to consider: an IQ score is not a unit of measurement. For example, someone with an IQ score of 130 is not 30 per cent smarter than someone with an IQ score of 100. Given the changes to testing across the decades, it is also tricky to compare scores achieved at different times.
Theoretically, there is no limit to IQ scores. 200 is often seen as the theoretical peak score but some people have shot past that number.
Who has the highest IQ in the world?
Pictured above, Terence Tao is said to have the highest IQ score in the world currently, with an impressive score of between 225-230. If the Chinese-American mathematician scored 230 he is definitely out in front.
Effectively tying for the title, though, is Marilyn Vos Savant. Her recorded IQ in the Guinness World Records was 228, awarded between the 1986-1989 editions until the record was discontinued in 1990, with IQ scores deemed too unreliable to document.
Christopher Hirata has the second-highest confirmed IQ, with a staggering score of 225. There have been a few others with scores equal or higher. Again, the same caveat applies that IQ scores are to be taken with a grain of salt, especially for those before the IQ test was invented.
What has had the highest IQ ever?
It's tricky to judge who has had the highest IQ ever. For many great minds, the IQ test simply did not exist during their time on Earth. The validity of others who are said to have taken an intelligence test is in question, too, as official records are tough to locate.
However, this hasn't stopped some humans from being declared to have the highest IQ ever.
William James Sidis
Said to be the smartest person who has ever lived, William James Sidis is the benchmark for child prodigies. He was reportedly able to read the newspaper aged just 18 months and entered Harvard University aged 11, graduating at 16.
He wrote various studies, including creating a constructed language in the Book Of Vendergoord (aged 8) and The Animate And The Inanimate (which covered cosmology and the reversibility of the second law of thermodynamics and predicts the black hole).
In Psychology For The Millions, Abraham Sperling details how he had been told by Helena Sidis (William's sister) that "a few years before his death, her brother Bill took an intelligence test with a psychologist."
Sperling explains that William Sidis' "score was the very highest that had ever been obtained. In terms of IQ, the psychologist related that the figure would be between 250 and 300."
In the years since, however, the claims of Sidis' IQ score have been heavily disputed.
Ada Lovelace
The first computer scientist, Ada Lovelace is often mentioned when it comes to the most intelligent people who ever lived. Through her work on the Analytical Engine, she essentially invented the first computer programme the world had seen.
Christopher Michael Langan
Reported to have an IQ score of 195, Christopher Michael Langan is often considered one of the smartest people alive. The controversial figure has often sided with conspiracy theories and claims that the existence of God can be proven by mathematics.
Albert Einstein
Often regarded as one of the smartest people who ever lived, it is often claimed that Einstein's IQ was actually lower than you might think. Given that the test wasn't around when Einstein walked the Earth, however, it's impossible to know just how intelligent this famous scientist actually was.
Leonardo da Vinci
Another who is often regarded as one of the smartest people ever, Leonardo da Vinci was a mathematician, engineer, botanist, cartographer and much more, so it’s hard to single out one achievement.
Sho Yano
Sho Yano was a college freshman at the tender age of nine and became a medical doctor at just 21. This made him "the youngest student in the University of Chicago's history to receive an MD," according to Chicago Tribune.
Katherine Johnson
You will have come across mathematician Katherine Johnson if you've seen the Oscar-nominated film Hidden Figures. Her work was vital in early NASA space missions and played a role in getting astronauts John Glenn and Alan Shephard into space. Johnson's orbital calculations were even used in the Apollo missions.
Stephen Hawking
What can be said about Stephen Hawking? The Simpsons legend is one of history's most famous theoretical physicists and cosmologists. He famously showed that black holes radiate energy, slowly shrink, and explode in a flash of gamma rays, with Hawking radiation becoming a key cosmological theory.
Read more:
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- Who is the tallest person in the world?
- Does the brain really experience a ‘great restructuring’ after we turn 40?
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