Heritability lost; intelligence found

Probably nothing makes human beings more different from other species—and from one another— than their intelligence. The subject is of profound general interest—what the brain is for and how it works, the distinctiveness of the human mind, what makes us individual and human—yet delivers so little. Human intelligence remains poorly defined and characterized, even among those who most study it. Rather, it is described through metaphors such as processing strength, capacity or power— referred to as ‘g’—or intuitively meaningful attributes such as “‘catching on’, ‘making sense’ of things, or ‘figuring out’ what to do” [1]. James Flynn, Emeritus Professor in the Department of Politics at the University of Otago, New Zealand, has noted how attempts to define ‘general intelligence’ or g have lacked precision and have attracted little scientific consensus [2]. According to Ian Deary, Professor of Differential Psychology at the University of Edinburgh, UK, “There is no such thing as a theory of human intelligence differences—not in the way that grown-up sciences like physics or chemistry have theories” [3].