Two scenes from twenty-first-century America.

Mid-20th C. America (source)
Young friends cycle to church for Sunday services. They stash their bicycles by the side of the building, walk in sporting their aerodynamic spandex, and take their places in the pews.
Later that day a waitress at a nearby restaurant approaches a silver-haired couple squinting at their menus. “So, what can I get you guys?” she asks the pair.
Across a range of behaviors, from dress to forms of address, Americans have become strikingly informal: we deviate from convention more than we used to, and the conventions we do observe entail less deference to institutions such as churches and statuses such as advanced age.
Read the rest of this column at the Boston Review here.
Update (Nov. 19, 2017):
For a much fuller discussion (and criticism of) changes in men’s fashions, see this essay by G. Bruce Boyer.