How Many People Rate Themselves Above Average in Intelligence?

The belief that a majority of people rate their own intelligence as above average is often linked to the Dunning-Kruger effect, a cognitive bias where individuals with lower ability in a task overestimate their proficiency. In modern surveys, approximately 60-70% of respondents tend to rate their intelligence as above average, a statistic that seems statistically improbable given the tenets of normal distribution, where only 50% can be above average.

The Statistical Paradox and Cognitive Bias

Understanding this discrepancy requires delving into the realm of cognitive biases like the Dunning-Kruger effect. This bias causes individuals to overestimate their abilities, leading to misaligned self-assessments. For instance, think of the quote by comedian and philosopher George Carlin: “Think of how stupid the average person is. I mean really think about it. Now remember that half the people are even stupider than that!” This satirical statement humorously reflects the societal tendency to overestimate one's own intelligence.

Normal Distribution and IQ Scores

Assuming a normal distribution of intelligence, a reasonable assumption which would mean 50% are above average, provides a clearer picture. However, this distribution is not perfect. When considering the mean intelligence score of a given nation, defined as IQ 100, the reality is more nuanced.

If we define “average” as the mean intelligence score (IQ 100), then only 50% of the population would be above this benchmark. Yet, a more inclusive definition of “average” taken as the range of scores, particularly the lower end up to the median, places the threshold at 16%, according to Haier R. J. (2017).

Real-World Distribution and Skewness

In the real world, the distribution function of intelligence is actually skewed to the left. This skewness occurs because people with organic retardation or developmental disabilities are not included in the norming group. When they are added, the distribution becomes even more left-skewed, reflecting a larger proportion of individuals at the lower end of the intelligence spectrum.

According to the normal distribution curve, here's a breakdown of the percentages:

50% of people have an IQ above 100 67% fall between IQs of 85 and 115 16% are above an IQ of 115 (considered above average)

Statistically, if 67% of people are in the average range, then 16% are above average, while the remaining 17% are below average. However, in self-assessments, this percentage often appears higher, leading to the observed statistical paradox.

Conclusion

While it might seem logical that a third of the population should rate themselves above average, this is not the case in surveys. The skewed nature of the real-world distribution and the cognitive biases at play explain why self-assessments of intelligence frequently exceed the statistical reality. Understanding these concepts helps us navigate the complexities of self-perception and the nuances of cognitive biases in human behavior.

These insights have implications beyond just the realm of intelligence. They shed light on how we perceive our abilities compared to others, and the importance of recognizing cognitive biases to foster accurate self-assessment.

References:

Haier, R. J. (2017). The Neuroscience of Intelligence. Cambridge University Press.