In her dissertation, Gu examined how influencers’ emotions—such as positivity or negativity, happiness or neutrality—affect their popularity, promotional effectiveness and influence on societal topics on social media. “Many people think influencers always need to be positive to be successful, but that’s not true,” says Gu. “What matters most is whether their emotion expression is perceived to appropriate, authentic, and similar to the audience’s own feelings.”

In her studies, participants were shown a range of social media posts, profiles and stories with standardized manipulation, some of which adapted from authentic influencers’ content. For example, in one project, participants saw a fitness influencer promoting a product, either with a happy or with a neutral expression, with variation in images, caption, hashtags, and/or emojis.

The results show that happy expressions made little difference. Both versions were seen as equally persuasive. According to Gu, this may be because influencer marketing differs from traditional advertising. “On social media, it is often unclear whether the content is sponsored or a genuine experience. In that context, a neutral appearance may come across as a sign of objectivity, although we did not test this explanation directly,” she says.

As a mirroring insight, negative emotions also do not necessarily have negative consequences. In another project, Gu found that while negative expressions may seem less appropriate than positive ones, they may perceived to be more authentic. This perceived authenticity can, in some cases, offset their potential downsides.

Overall, the dissertation shows that three factors shape how people respond to influencers: Whether the emotion fits the situation, whether it appears genuine, and whether it matches the audiences’ own emotional state. That last factor, in particular, plays an important role in shaping opinions, for example affecting how certain people feel about their attitudes toward societal issues.

According to Gu, communication on social media is more complex than is often assumed. Images, captions, emojis and other elements interact to shape how an emotional message is interpreted. “It’s not as simple as: positive is better,” she says.

The conclusion: influencers do not always have to be cheerful to be successful. What matters is how their emotions are perceived by their audience — whether they are seen as appropriate, authentic and similar by their audience. “Perceptions are more important than the expression itself,” Gu concludes.