## 14 August 2013

### Spatial Ability Predictive Independent Of SAT Scores

A study of the relationship between SAT scores, a test of spatial ability taken at age 13, and high level performance in related areas such as publishing peer reviewed STEM papers and obtaining patents, shows that IQ differences in excess of the 99.5th percentile and spatial ability independent of SAT scores significantly predict performance even among this elite group measured for very high level and complex professional performances (from here).

The study is drawn from a project called the "Study of Mathematically Precocious Youth", which studied people who are roughly my peers in mathematical ability (I taught myself geometry, pre-calculus, three semesters of college calculus, college linear algebra, and discrete mathematics from textbooks in high school rather than attending math classes and then majored in math in college because I didn't have to take many classes in the field to complete my major).  They are also only modestly older than I am.
[Abstract:] In the late 1970s, 563 intellectually talented 13-year-olds (identified by the SAT as in the top 0.5% of ability) were assessed on spatial ability. More than 30 years later, the present study evaluated whether spatial ability provided incremental validity (beyond the SAT’s mathematical and verbal reasoning subtests) for differentially predicting which of these individuals had patents and three classes of refereed publications. . . .[T]he SAT subtests jointly accounted for 10.8% of the variance among these outcomes (p < .01); when spatial ability was added, an additional 7.6% was accounted for—a statistically significant increase (p < .01). . . .
[Steve Hsu commentary:] SAT composite accounted for 10 percent of variance in research success even within this already gifted subpopulation. This non-zero result, despite the restriction of range, contradicts the Gladwellian claim that IQ above 120 does not provide additional returns. In fact, the higher the IQ score above the 99.5 percentile cutoff for this group, the greater the likelihood that an individual has been awarded a patent or has published a research paper.
Spatial ability was much less relevant to papers on biology and medicine (and outside STEM fields) than it was in the areas of patents and non-biology and medicine STEM papers (even though math SAT scores were about equally relevant to biology and medicine and to patents).

Verbal ability was actually more relevant to STEM publication rates than to non-STEM publications rates, but was largely irrelevant to getting patents, which may in part be an artifact of greater variability in verbal ability in the subpopulation.