Imagine being in a clothing shop and hearing the salesperson tell another customer, “You have fantastic fashion sense”. The other customer can expect to feel flattered, but simply witnessing this exchange has an effect on the observer, too: it elicits complex and conflicting emotions and ultimately could influence their purchase decision.

This was the finding of a study by Elaine Chan and Jaideep Sengupta, who were particularly interested in the effects of observing “sincere flattery” – the kind associated with hearing another customer being flattered after making a purchase rather than before, when it might be assumed the salesperson is motivated by wanting to secure a sale. While other research has suggested observers have a positive reaction to sincere flattery, the authors begged to differ.

“Observers will react negatively even to non-suspicious flattery because observing someone else being flattered automatically evokes an envy-inducing social comparison, which yields a negative response towards the flatterer. Deliberating on the flatterer’s sincerity should lead to a more positive judgment, but the initial negative reaction should stay on as an implicit attitude,” they said.

Implicit (or automatic) attitudes are formed immediately, like a gut reaction, while explicit attitudes kick in after the observer has had time to process what they have seen.

The authors tested these ideas in four experiments that looked at what happens when a customer in a store observes a salesperson flattering another customer on her dress sense. Participants’ reactions towards the flatterer were measured both in terms of their gut reaction (i.e., the implicit attitude – this was assessed by giving participants very little time to provide their responses) and also in terms of their more thought-out response (i.e., the explicit attitude).

The first experiment confirmed that envy was driving the response to observed flattery: observers were more likely to react negatively, especially in their implicit reactions, when the flattered customer was similar to themselves rather than dissimilar – envy has been shown to be stronger when you compare yourself with a similar person.

“This result speaks to our thesis that observers are not objective processors of flattery; rather, they are negative-biased and they react unfavourably towards even sincere flattery. This negative bias is restricted to implicit attitudes,” the authors said.

Next, they found that observers experienced benign envy (which motivates the person to improve themselves) if the flattery was perceived as sincere, but malicious envy (which motivates a desire to harm the envied person) if it was seen as insincere. Both of these types of envy cause frustration, however – because of a feeling that one is not good enough. And that frustration caused the observer, even when witnessing praise that they perceived to be sincere, to end up disliking the flatterer – and also the person being flattered. Again, all of this was observed for implicit reactions, not for the explicit, thought-out attitude.

Finally, the last study showed that a desire to reduce envy can goad the observer to take action over time that may actually benefit the flatterer – in this case, the salesperson who had induced the envy. Participants who observed flattery were more willing to buy a stylish but expensive pair of jeans over a less stylish and less expensive pair –this helped them reduce their feelings of envy by improving their perceptions of themselves as being fashionable and stylish. This was specially likely after a time delay between observing the flattery and making the purchase decision – “when the hostility towards the salesperson has become dissociated from the purchase decision,” the authors said.

The findings have interesting implications for marketers, sales people and other “persuasion agents” who use flattery as a tactic. “Flattery that is targeted at one person may often by overheard by another. The benefits of winning the targeted customer’s appreciation will be significantly undercut if observers react adversely to the salesperson in such situations. Our findings offer room for both caution and optimism in this regard: observers do react negatively in terms of their attitudes, but their subsequent behaviour might be beneficial for the store,” the authors said.