| Evidence suggests that executive functioning (EF), an umbrella terms that encompasses a group of higher-order cognitive processes that mediate one's intrinsic ability to respond in an adaptive manner to novel situations, is linearly related to intelligence (IQ) but moreso for individuals with Full-Scale IQ below 110 (Average to Below Average ranges). However, many early studies looked at this relationship using EF as a unitary construct rather than a multi-dimensional collection of related but distinct cognitive processes. It was not until recently that studies IQ and how it relates to the domains of EF; however, until now no study had yet to look at how the multiple facets of EF relate to IQ amongst varying levels of IQ. To examine this issue, we used a non-clinical, neurologically intact sample of 158 young adults using a comprehensive batter of EF and IQ measures. Confirmatory factor analysis found a three factor solution of EF best fit the data: Inhibition, Set-Shifting, and Planning. These findings also confirmed that IQ predicts EF functioning across the spectrum of varying IQs, with more strong relationships happening on the middle-to-lower end of the spectrum. Set-shifting and Inhibition were found to be most closely related to IQ across all cases; however, both were more strongly related to individuals of Below Average and Average IQ. The strength and nature of the associations between IQ and the different domains of EF has practical and conceptual significance for clinical practice, as well be discussed. |
