By: Dr. Fabiano de Abreu Agrela Rodrigues, PhD in Neuroscience, President of the ISI Society, and Coordinator of Intertel Brazil
The measurement of intelligence quotient (IQ) is a globally relevant topic, particularly in countries where a significant portion of the population has undergone intelligence testing. Nations such as the United States, Israel, South Korea, Singapore, and England stand out in this scenario. Other countries, including Sweden, Russia, Germany, and China, also exhibit a widespread culture of cognitive assessment, especially in educational and military contexts.
The rationale behind this practice lies in public and cultural policies that value early identification and utilization of intellectual talents. In the United States, the use of tests like the SAT (Scholastic Assessment Test) and the ACT (American College Testing) is common for university selection, which indirectly provides an estimate of the cognitive potential of the nation’s youth. In Israel, all mandatory military service recruits undergo cognitive assessments, a practice similar to that adopted by Sweden until 2010. In South Korea and Singapore, high academic competitiveness encourages the use of standardized tests that also correlate with intellectual performance. In the United Kingdom, in addition to school evaluations, there is a strong tradition of psychometric testing in corporate and academic selection processes, and it is also the birthplace of pioneering high-IQ societies like Mensa.
It is noteworthy how the United States hosts most of the world’s high-IQ societies, highlighting American culture’s strong interest in identifying and cultivating exceptional intelligence. The Triple Nine Society, founded in 1978, brings together individuals with an IQ above 146 points. Intertel, also American, was founded in 1966 and is aimed at individuals in the 99th percentile of intelligence, with an IQ starting at 135. The ISI Society accepts members with IQ scores above 148 and notable creative achievements. Additionally, the IIS Society focuses on individuals with IQs above 140, accepting children as young as six years old.
This concentration of societies in the U.S. suggests a cultural interest in promoting intellectual development and interaction among individuals with high cognitive capacity.
In these countries, it is likely that prominent figures—academics, business leaders, and public figures—know their own IQ. However, many choose not to disclose this information, whether for privacy reasons or to avoid social stigma. It is important to note that while some view IQ as a symbol of intellectual prestige, others prefer not to be labeled by a number.
The main tests applied globally include the SAT and ACT in the United States, the GAT (General Ability Test) in South Korea, the Gaokao in China, the Matrigma in Sweden, the 11-Plus in the United Kingdom, and the Wonderlic in international corporate environments. These tests vary in complexity and purpose but all provide a measure of cognitive abilities, often with scores ranging from 200 to 1600 points (in the case of the SAT) or in specific scales, such as the Chinese Gaokao.
When compared to classic IQ tests such as the WAIS (Wechsler Adult Intelligence Scale), WISC (Wechsler Intelligence Scale for Children), Cattell, and Binet, these standardized tests present significant differences. Traditional IQ tests assess a broader spectrum of cognitive skills, including working memory, verbal, spatial, and information processing abilities. Meanwhile, tests like the SAT and ACT more directly measure academic skills and logical reasoning, being less comprehensive in terms of global intelligence assessment.
Among all these methods, the WAIS and WISC are widely considered the most complete and reliable for assessing human intelligence, as they were specifically developed to measure IQ, unlike academic tests that indirectly reflect aspects of cognition. Estimates suggest that a perfect score on the SAT (1600 points) could correspond to an IQ of approximately 145-155 on the WAIS, depending on the correlation and conversion model used. However, this equivalence is neither direct nor precise, as the SAT was designed to assess academic aptitude, not global intelligence.
An interesting question is why a person who takes a test in the United States might not maintain the same score when taking it in Germany, for example. This occurs due to cultural, linguistic, and educational differences. The cultural context directly influences performance on IQ tests, as many items require specific knowledge and cultural references. Additionally, the test format itself can vary, affecting the consistency of scores.
The science behind IQ assessment involves understanding that intelligence is a multidimensional construct. While standardized tests offer a limited view, traditional IQ tests, especially those that include assessments of emotional, social, and creative intelligence, provide a more holistic perspective. Considering these factors reinforces the importance of contextualizing cognitive test results within individual and cultural particularities, avoiding premature generalizations.
For these reasons, IQ scores between individuals cannot be directly compared unless all are subjected to the same test, such as the WAIS, which is considered the most scientifically accepted for this parameter. Only this standardization would allow a fair and reliable comparison between individuals from different cultural and educational backgrounds.