The Rarity of Super-High IQs: Estimating the Global Population with IQs Over 190
Introduction
Estimating the number of individuals with an IQ over 190 is a complex task due to the rarity of such high scores and the limitations inherent in IQ testing. Traditionally, IQ scores are distributed according to a bell curve with a mean of 100 and a standard deviation of 15. Scores above 190 are exceedingly rare, indicating that these individuals are extremely exceptional in terms of cognitive ability.
Understanding the Distribution of IQ Scores
The distribution of IQ scores can be modeled using the properties of a normal distribution. An IQ score of 190 is approximately 6.67 standard deviations above the mean. In a normally distributed population, the number of individuals scoring above 190 is exceedingly small—often estimated to be less than 1 in several million people.
Mettering the Population with Super-High IQs
Given that the world's population is around 8 billion, the estimated number of individuals with an IQ over 190 is likely to be extremely small. Various estimates suggest that the actual number could range from 10 to 20 people. These figures, however, are rough estimates and should be interpreted with caution due to the variability in IQ testing and definitions of intelligence.
On a scale with a standard deviation of 15 (SD15), an IQ of 190 would be 6 standard deviations away from the mean, suggesting a rarity of about 1 in a billion. This would translate to around 7-8 individuals globally.
For an SD16 scale, which is similar to the Stanford-Binet test, an IQ of 190 would be approximately 6.25 standard deviations above the mean, indicating a similarly rare occurrence, possibly even higher than 1 in a billion. This would suggest the possibility of 5-6 individuals globally.
Interpreting IQ Test Results
It is important to consider that these estimates are based on the assumption that IQ scores follow a perfect normal distribution. However, evidence suggests that IQ tests may exhibit "fat tails," meaning that the distribution of scores may extend further than a standard normal distribution. This could potentially increase the rarity of individuals scoring over 190.
Moreover, it is crucial to understand that scores alone are often misleading. The percentile rank, which indicates how an individual's score compares to a large population, provides a more accurate measure of cognitive ability. For example, if a person scored in the 99th percentile, it means that they performed better than 99% of the population. This percentile can be used to make more precise comparisons between different IQ tests.
It is noteworthy that few IQ tests have been administered that reach scores as high as 190. Most well-recognized tests have a top score around 170, and even fewer go beyond. Therefore, any score claiming to be over 190 should be critically evaluated, as it may not reflect a true super-high IQ but rather a flawed or inaccurate assessment.
Understanding the nuances of IQ testing and the psychological and neurological mechanisms behind very high scores is essential for accurate interpretation and comparison. As research in the field of intelligence continues to evolve, we may gain a better understanding of the true nature and rarity of individuals with such exceptional cognitive abilities.
Conclusion
Estimating the number of individuals with an IQ over 190 is a challenging task due to the rarity of such high scores and the limitations of IQ testing. While rough estimates suggest that the number of such individuals may be in the range of 10 to 20 globally, the variability in test scaling and distribution make these estimates imprecise. A more accurate understanding of this phenomenon requires careful consideration of the test scores and their interpretation within the context of the distribution of IQ scores.