Hanson seems to suggest that the cultural drift is aimless or unguided. I'd argue the opposite. There are exceptions to this, especially very recently, but almost all cultural shifts in the west of the past 150 years can be traced to one single thing: individualism.

You can trace individualism to various started places, like the Protestant Reformation's assertion that individuals have a direct connection to the divine. But certainly by the time John Stuart Mill took up the cause, it already had a great deal of momentum and it was adopted as an ethos.

Since Mill, almost every cultural shift has been reconciling the baggage of the past with individualism. The civil rights movement, women's suffrage, the decline of organized religion and promotion of "individual spirituality" all have the through-line of individualism. Name for me a single twentieth century cultural shift, in the "western world," that wasn't about the individual's triumph over the collective.

There are some more recent exceptions from this century though, where the pendulum might be swinging away from the individual and toward the collective. Emphasizing group identity over individual identity comes to mind as an example.