Workers drop a smiley face into their Slack messages every day without thinking twice, and the three-variable rule researchers found among 243 participants that decides whether that emoji makes you look brilliant or incompetent

The researchers asked 243 participants to read IMs varying in sentence valence (positive, negative, neutral), emoji valence (positive, negative, no emoji), and sender gender (man, woman). Their emoji selection was limited to only three options: a positive “grinning face” emoji, a negative “angry face” emoji, or no emoji at all. Positive emojis enhanced competence perceptions when paired with positive or neutral sentences, but had no effect with negative sentences. The gender dimension added another layer: women participants perceived negative emojis sent by women senders more negatively than those sent by men. A negative emoji on any message erodes that perception almost immediately, and a positive emoji on a negative message offers no rescue.