1. An intelligence quotient, or IQ, is a score derived from one of several standardized tests designed to assess intelligence. The abbreviation "IQ" comes from the German term Intelligenz - Quotient, originally coined by psychologist William Stern. When modern IQ tests are devised, the mean (average) score within an age group is set to 100 and the standard deviation (SD) almost always to 15. Thus, the intention is that approximately 95% of the population scores within two SDs of the mean, i.e. has an IQ between 70 and 130. What is IQ ???

2. IQ scores have been shown to be associated with such factors as morbidity and mortality, parental social status and, to a substantial degree, biological parental IQ. While the heritability of IQ has been investigated for nearly a century, there is still debate about the significance of heritability estimates and the mechanisms of inheritance. IQ scores are used as predictors of educational achievement, special needs, job performance and income. They are also used to study IQ distributions in populations and the correlations between IQ and other variables. The average IQ scores for many populations have been rising at an average rate of three points per decade since the early 20th century, a phenomenon called the Flynn effect. It is disputed whether these changes in scores reflect real changes in intellectual abilities. Factors indicating on IQ 3. Well-known modern IQ tests include Raven's Progressive Matrices, Wechsler Adult Intelligence Scale, Wechsler Intelligence Scale for Children, Stanford- Binet, Woodcock-Johnson Tests of Cognitive Abilities, and Kaufman Assessment Battery for Children. Approximately 95% of the population have scores within two standard deviations (SD) of the mean. If one SD is 15 points, as is common in almost all modern tests, then 95% of the population are within a range of 70 to 130, and 98% are below 131. Alternatively, two-thirds of the population have IQ scores within one SD of the mean, i.e. within the range 85-115. IQ scales are ordinally scaled.While one standard deviation is 15 points, and two SDs are 30 points, and so on, this does not imply that mental ability is linearly related to IQ, such that IQ 50 means half the cognitive ability of IQ 100. In particular, IQ points are not percentage points. The correlation between IQ test results and achievement test results is about 0.7. Modern IQ tests 4. IQ can change to some degree over the course of childhood.However, in one longitudinal study, the mean IQ scores of tests at ages 17 and 18 were correlated at r=.86 with the mean scores of tests at ages five, six and seven and at r=.96 with the mean scores of tests at ages 11, 12 and 13. IQ scores for children are relative to children of a similar age. That is, a child of a certain age does not do as well on the tests as an older child or an adult with the same IQ. But relative to persons of a similar age, or other adults in the case of adults, they do equally well if the IQ scores are the same. To convert a child's IQ score into an adult score the following calculation should be made: child IQ score * age/16=adults IQ score The number 16 is used to indicate the age at which supposedly the IQ reaches its peak. IQ and age 5. Name Score Details Abdesselam Jelloul 198 Scored in a 2012 test including 13 dimensions of intelligence. William J. Sidis 197 Child prodigy with exceptional mathematical & linguistic abilities. Christopher Langan 195 Called "the smartest man in America". Garry Kasparov 190 Chess grandmaster, writer and political activist. Leonardo da Vinci ~190 A genius polymath: painter, sculptor, architect, scientist... Ludwig Wittgenstein 190 Philosopher primarily in logic, the philosophy of mathematics... Sir Isaac Newton ~190 Physicist, mathematician, astronomer, natural philosopher, alchemist... Bobby Fischer 187 A chess Grandmaster and a child prodigy. Marilyn vos Savant 185 Magazine columnist, author, lecturer, and playwright. Kim Ung-Yong 170 Korean civil engineer and former child prodigy. Albert Einstein 160 Theoretical physicist (the general theory of relativity). Akrit Jaswal 146 Child prodigy who performed his first surgery at the age of 7. The highest IQ score There are a lot of people who say that the highest IQ ever is 228 by Marilyn vos Savant but theoretically it is impossible to have an IQ over 200. here are some of the highest IQs known till nowadays 6. lowest IQ in the world Usually an IQ under 70 is categorized as "Definite feeble- mindedness", 5% of people have an IQ under 70 and this is generally considered as the benchmark for "mental retardation", a condition of limited mental ability in that it produces difficulty in adapting to the demands of life. However, people with smooth brains or lissencaphaly tend to get the lowest IQ's, which is around 20. Adaptive behavior ratings scales can go lower, but there's really no point, because once you get to IQ's that low, there's virtually no real difference in performance.. 7. A MODEL OF IQ TESTS 8. THE END