On Psychometrics, Cognitive Ability, and Achievement in the STEM Fields

Yesterday, I stumbled across an article that on the surface (based on the title, at least) appears to be an article for parents wanting to encourage genius in their children, but is in actuality a nice history of psychometrics, the measurement of cognitive ability, and evolution of gifted programs. The article focuses on the research of psychometrician Julian Stanley, who conducted the Study of Mathematically Precocious Youth (SMPY):

As the longest-running current longitudinal survey of intellectually talented children, SMPY has for 45 years tracked the careers and accomplishments of some 5,000 individuals, many of whom have gone on to become high-achieving scientists. The study's ever-growing data set has generated more than 400 papers and several books, and provided key insights into how to spot and develop talent in science, technology, engineering, mathematics (STEM) and beyond.

The study was inspired in part by Lewis Terman's famous study of genetics and genius; what made this study so interesting is that it limited inclusion in the study to people with IQs in the genius range, but found low levels of success in the sample, and also missed by only a few points including two Nobel Prize laureates. This resulted in the conclusion that IQ, once you get to a certain level, does not necessarily correlate with greater success and achievement, a conclusion Malcolm Gladwell echoed in his book Outliers.

But Stanley saw some problems with these results, the most important of which was that Terman was using overall IQ score, which is a measure of general intelligence, to attempt to identify people gifted in science and math, which are specific intelligences. So Stanley skipped using cognitive ability tests and opted to use the quantitative portion of the SAT. Later on, they used an even more specific indicator of mathematical ability - spatial reasoning:

A 2013 analysis found a correlation between the number of patents and peer-refereed publications that people had produced and their earlier scores on SATs and spatial-ability tests. The SAT tests jointly accounted for about 11% of the variance; spatial ability accounted for an additional 7.6%.

Evidence from Stanley's work has resulted in changes in how gifted individuals are identified and educated, including the notion of skipping grades or allowing students to complete materials at their own pace and/or take advanced coursework while remaining in the same grade level (something I did during my time in school). What it comes down to is the importance of proper measurement - knowing what to measure to understand and predict certain outcomes.