Getting Spearman off the skyhook: One more in a century (since Thomson, 1916) of attempts to vanquish g

We provide seven responses to Kovacs and Conway’s wide-ranging theory of intelligence differences. In the first six, we: reflect on the past theories that can be heard in this new one and how they have fared; discuss whether, in their present state, cognitive processes inferred from mental tests can be considered isomorphic with brain processes and can bear explanatory weight in theories of intelligence; and suggest that the positive manifold might be a formative biological latent trait while probably being a reflective psychological one. In the seventh, we attempt to test some hypotheses from Process Overlap Theory in our own Lothian Birth Cohort 1936 data.