New York, Dec 5 (IANS): Advertisements that make people laugh are not always in the best interest of brands and can prove to be harmful, warns a study that has cautioned ad makers.

The findings showed that people find humour in "benign violations" -- things that somehow threatens their sense of well-being, personal identity or beliefs -- only if they are harmless or inconsequential.

"Different ads can be equally humorous to consumers but have very different effects on brand attitudes, depending on the type of humour used," said lead author Caleb Warren, Assistant Professor at the University of Arizona in the US.

People's attitudes toward brands are important, as they ultimately influence purchasing decisions.

Thus, advertisers should stay away from ads that feature highly inappropriate humour, humour with a specific target or "butt of the joke," and humour that prompts avoidance by eliciting feelings such as disgust in addition to laughter.

"When there's a more severe violation, even though people find it funny, they like the brand or the retailer selling it less," Warren added.

In one of the experiments conducted, the researchers looked at the effects of humour targeting a single person or group of people.

They created two versions of an insurance company ad showing a car crashed into the side of a house. One had the caption "Everyone drives like an idiot sometimes," while the other said "Everyone drives like a woman,..."

A control ad merely showed a truck with a smashed front end and the words "Accidents happen sometimes."

The "inclusive" ad, which, was shown only to male participants, mocked bad drivers in general, improved brand attitudes relative to the control ad, while the "exclusive" ad, mocking only women drivers, did not.

Testing audience before launching an ad is a good idea to gauge whether something will be perceived as funny, the researchers suggested.

The study was published in the Journal of Marketing Behaviour.