Right after Bill Clinton’s first scandal the media pushed all court cases where “and the accused didn’t even say he was sorry.” Dozens of them. The tears to the jury became a trend.
Now the rule is: Watch to see if the cameras are on, then start the phony tears.
I read that in the golden age of films they brought little droppers of glycerine to soundstages to put into the eyes of actors to get them “crying.”
Margaret O'Brien was a great child star ( she could REALLY act! ) and she was very valued because she COULD and DID cry easily on cue; for but one example.
Another stage trick was to pull out a nose hair.