A vast amount of information has been accumulated within the last three decades with respect to scientists’ attempt to understand the etiology of variance contributing to the so-called general cognitive ability factor (or general intelligence, g). Whether this information is going to be valuable in the long run, and whether it will contribute to our understanding of the origin and the development of cognition, is yet to be determined. At this point, we still do not know what the etiology of the general cognitive ability is, but we have impressive amounts of descriptive information about the general ability’s correlates, its links to other cognitive abilities, and its developmental fluctuations.