Is the period really “pissed”? The effect of punctuation and message length on perceptions in digital communication

Including a period at the end of a one-word text message (“yes.”) can elicit perceptions of insincerity and negativity. We assessed whether these negative perceptions would hold in longer messages. Australian undergraduates (N = 200) read 30 fictitious message exchanges; positive, neutral, or negative in valence. Exchanges ended in a short (one word), medium (three to four words), or long (six to eight words) message; half with a final period, half without. Participants rated how they thought the friend felt about their message, on a 7-point scale. Across valences, messages with a period were rated more negatively than those without, as were both short and medium messages. In long messages, the period's presence or absence did not significantly affect ratings. The results imply that this punctuation mark can convey emotional or grammatical information, depending on message length. The findings have implications for the way people compose and interpret digital messages.