It's predictive to an extant. Many people who have taken up the mantel of IQ have taken it too far. And their (largely political) detractors have dismissed them merely because they have taken it too far. But much of it is still true from a more measured perspective.

Which has some very inconvenient / awkward implications for many people who are seeking to dismiss it outright, rather than dismiss particular proponents of it...

But taking any idea to the extremes, bulldozing over context and constraints of the data, and making grand generalizations from very simple base ideas is the bread and butter of politics, economics, and any bestselling non-fiction.

Popular discourse may be a tribal battle between extremes, but real life isn't...