Spearman's g found in 31 non-Western nations: Strong evidence that g is a universal phenomenon

Psychol Bull. 2019 Mar;145(3):237-272. doi: 10.1037/bul0000184. Epub 2019 Jan 14.

Abstract

Spearman's g is the name for the shared variance across a set of intercorrelating cognitive tasks. For some-but not all-theorists, g is defined as general intelligence. While g is robustly observed in Western populations, it is questionable whether g is manifested in cognitive data from other cultural groups. To test whether g is a cross-cultural phenomenon, we searched for correlation matrices or data files containing cognitive variables collected from individuals in non-Western, nonindustrialized nations. We subjected these data to exploratory factor analysis (EFA) using promax rotation and 2 modern methods of selecting the number of factors. Samples that produced more than 1 factor were then subjected to a second-order EFA using the same procedures and a Schmid-Leiman solution. Across 97 samples from 31 countries totaling 52,340 individuals, we found that a single factor emerged unambiguously from 71 samples (73.2%) and that 23 of the remaining 26 samples (88.5%) produced a single second-order factor. The first factor in the initial EFA explained an average of 45.9% of observed variable variance (SD = 12.9%), which is similar to what is seen in Western samples. One sample that produced multiple second-order factors only did so with 1 method of selecting the number of factors in the initial EFA; the alternate method of selecting the number of factors produced a single higher-order factor. Factor extraction in a higher-order EFA was not possible in 2 samples. These results show that g appears in many cultures and is likely a universal phenomenon in humans. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Cognition*
  • Cross-Cultural Comparison*
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Intelligence*
  • Internationality*
  • Male
  • Middle Aged
  • Psychometrics
  • Research Design
  • Young Adult