Increasingly, says Professor Crystal, whose books include “Making a Point: The Persnickety Story of English Punctuation,” the period is being deployed as a weapon to show irony, syntactic snark, insincerity, even aggression
If the love of your life just canceled the candlelit, six-course, home-cooked dinner you have prepared, you are best advised to include a period when you respond “Fine.” to show annoyance
“Fine” or “Fine!,” in contrast, could denote acquiescence or blithe acceptance
“The period now has an emotional charge and has become an emoticon of sorts,” Professor Crystal said
Researchers at Binghamton University in New York and Rutgers University in New Jersey have also recently noted the period’s new semantic force
They asked 126 undergraduate students to review 16 exchanges, some in text messages, some in handwritten notes, that had one-word affirmative responses (Okay, Sure, Yeah, Yup) Some had periods, while others did not
Those text message with periods were rated as less sincere, the study found, whereas it made no difference in the notes penned by hand
Here is the full Dan Bilefsky story (NYT).