The way to reality-check someone's impression of how the world works is to gather more data. In human intelligence research, James R. Flynn (a co-author of the paper under review here) has enjoyed particular success in making claims that run against the "everyone knows" bias of individual differences psychologists, and then being backed up by other psychologistics (and getting published in the top journals in psychology) when data are found to back him up.
Here is what Arthur Jensen said about Flynn quite a few years ago, and he hasn't retracted this statment: "Now and then I am asked . . . who, in my opinion, are the most respectable critics of my position on the race-IQ issue? The name James R. Flynn is by far the first that comes to mind." Modgil, Sohan & Modgil, Celia (Eds.) (1987) Arthur Jensen: Concensus and Controversy New York: Falmer. Here's what Charles Murray (all right, neither a psychologist nor a geneticist, but, as the review points out, an author who has written about these issues) says in his back cover blurb for Flynn's book What Is Intelligence?: "This book is a gold mine of pointers to interesting work, much of which was new to me. All of us who wrestle with the extraordinarily difficult questions about intelligence that Flynn discusses are in his debt." As N. J. Mackintosh writes about the data Flynn found in his book IQ and Human Intelligence: "the data are surprising, demolish some long-cherished beliefs, and raise a number of other interesting issues along the way." Flynn has earned the respect and praise of any honest researcher who takes time to read the primary source literature. Robert Sternberg, Ian Deary, Stephen Pinker, Stephen Ceci, Sir Michael Rutter, and plenty of other eminent psychologists recommend Flynn's research.