We've all seen the Hollywood movies where a smart-mouthed reporter or gangster or Lois Lane or whatever is speaking at 90-miles-an-hour. All of the dialogue on those old comedies is lightning fast. Can any historian definitively answer if this was just a hackneyed acting style from the vaudeville days or were Americans just ripped silly on amphetamines?
hi! not discouraging more/better info on this particular point, but meanwhile check out this previous discussion:
Did people in the 20s-40s normally talk as fast as they did in the movies of that time?
... and take a skim through this section of the FAQ, which, despite it's title includes discussion on several aspects of speaking and mannerisms
(and, will endeavor to track down more.. seems to me there were a few very good related discussions in the last few months)
edit: this is one I was thinking of. not quite on topic, but gives more background re changes in American film acting