Sad face: emoji are not appropriate for expressing intense negativity online

Emoji are graphical representations, for example of facial expressions of emotion, but also of other non-facial and non-emotional concepts, that function as non-verbal cues in digital text-based communication. Previous work has shown that while emotional face emoji effectively clarify the affective meaning of any text message, their effects are stronger for positive contents. The present study tested whether this can be explained by the valence intensity of text messages. N = 126 participants recruited on Prolific Academic were asked to read either mildly or highly positive or negative text messages that either included a valence-congruent emoji or not. They were asked to rate the perceived valence of the messages, how appropriately they thought the messages were composed, and to indicate how they themselves felt after reading the messages as a measure of emotional contagion. We found that for positive messages of all valence intensities, messages including emoji were seen as more positive and appropriately composed and induced stronger emotional contagion. While we found comparable effects for mildly negative messages, emoji did not affect the perception of highly negative messages in any way. Thus, our findings qualify the previously observed asymmetry: emoji are generally effective to clarify any positive content in text messages. However, for negative messages, their effectiveness is limited to mildly negative content. These findings are embedded in the context of social theories of emotion, and we discuss their significance for digital text-based communication of emotional content, and emoji design more generally.