Low Base Rates and a High IQ Selection Threshold Prevented Terman from Identifying Future Nobelists

Abstract

Although the accomplishments of the 1,528 subjects of the Genetic Studies of Genius are impressive, they do not represent the pinnacle of human achievement. Since the early 1990s, commentators have criticized the study because two future Nobelists—William Shockley and Luis Alvarez—were among the candidates screened for the study; but they were rejected because their IQ scores were too low. Critics see this as a flaw of Terman’s methodology and/or intelligence testing. This study simulates the Terman’s sampling procedure to estimate the probability that Terman would have selected one or both future Nobelists from a population of 168,000 candidates. Using simulations, we created a model that reflected the reliability of the IQ scores used to select individuals for the Genetic Studies of Genius and the relationship between IQ and Nobelist status. Results showed that it was unlikely for Terman to identify children who would later earn Nobel prizes, mostly because of the low base rate of earning a Nobel and the high minimum IQ needed to be selected for Terman’s study. Changes to the methodology that would have been required to select one or both Nobelists were not practical. Therefore, future Nobelists’ absence from the Genetic Studies of Genius sample is not a fatal flaw of intelligence testing or Terman’s study. Instead, predicting high levels of eminence requires measuring a variety of relevant cognitive and non-cognitive variables. A preprint version of this paper is available at https://psyarxiv.com/g4x6r/. Simulation code and results and reliability generalization information are available at https://osf.io/3xfe8/.

Locations

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