Most of the psychologists across the world consider IQ as the best metric to measure the intelligence of a person.
In present world, more than 50% of people have IQ between 90 to 110, 2.5% individuals who are mentally deficient/impaired have an IQ score under 70, 0.5% of people with IQ score of above 140 are genius and over 2.5% people with IQ score of 130 are intelligent.
Take a look at the 10 smartest people on the earth with great IQ:
Stephen W. Hawking:
Age: 70 years
IQ score: 160
Achievements: Author of 7 best selling books
Kim Ung-Yong:
Age: 50 years
IQ score: 210
Achievements: Worked for NASA at early age and often called as child prodigy.
Garry kasprov:
Age: 49 years
IQ score: 190
Achievements: Founder of United Civil Front and ranked number one as a chess player for several years.
Sir Andrew Wiles:
Age: 70 years
IQ score: 160
Achievements: Has solved 'Fermat's last theorem', a 358 year old mathematic problem and received 15 prizes for his contribution in science and maths.