In lower trust countries people justify their various forms of lying just as we high trust people justify the externalities caused by our combination of linguistic conveniences, methodological habits, variations in morality and ethics, and of course political correctness
That does not mean that just as we live considerably better than all these lower trust societies, that we world not yet again live better than we do now if we spoke more truthfully than we do now.
The reasons are not terribly hard to understand. And in simple terms the people you associate with are more important in determining your prosperity and safety than your own abilities.
So just as the Flynn effect is the product of reducing the bottom and saturating everyone else in scientific general rules, we can likewise expect the same increase by saturating everyone in testimonial speech and reducing the bottom.
We are not yet at the end of history. There is a long way to go. And perhaps the reson we seem stalled in physics is because we aren’t producing enough patterns in our own behavior to deduce the construction of the rest of the universe.