Geary puts forward an appealing argument for the consideration of mitochondrial functioning as a candidate for a formative g Geary (2019); it is also an ambitious argument. After Spearman’s discovery of a psychometric in Spearman (1904) and his speculations about a psychological g in Spearman (1927), researchers have been attracted by the simplicity of a single unifying factor. To date, the identification of this hypothesized factor is still awaited. In fact, various contemporary theories suggest that local complex dynamic mechanisms drive the emergence of the global phenomenon g Dickens and Flynn (2001); van der Maas et al. (2006); Kovacs and Conway (2016); Savi et al. (2019).

In the following, we comment on Geary’s attempt at debunking g and suggest a different—but nonetheless compatible—perspective. We also—not entirely accidentally—suggest the network perspective from van der Maas et al (2019) as a more principled method that enables the study of the influence of potentially powerful factors on intelligence in their biological, psychological, and societal context.