A new study published in the journal Computers in Human Behavior say that people who end their text messages with periods are jerks. Also, they are perceived as less sincere. The researchers studied 126 undergraduate participants exchanging a series of 16 texts in either text or handwritten form.

“Text messaging is one of the most frequently used computer-mediated communication (CMC) methods. The rapid pace of texting mimics face-to-face communication, leading to the question of whether the critical non-verbal aspects of conversation, such as tone, are expressed in CMC,” the researchers write in the study.

Each exchange had a version that ended with a period and a version that did not end with any punctuation.

Text messages that ended with periods were seen as less sincere. The use of periods in handwritten notes, however, were not rated any more or less sincere.

“Texting is lacking many of the social cues used in actual face-to-face conversations. When speaking, people easily convey social and emotional information with eye gaze, facial expressions, tone of voice, pauses, and so on,” Klin said in a statement. “People obviously can’t use these mechanisms when they are texting. Thus, it makes sense that texters rely on what they have available to them — emoticons, deliberate misspellings that mimic speech sounds and, according to our data, punctuation.”