I came across this advert after I searched ‘bad advertisement’ on Google. As you can see, Dettol tried to link an extreme situation with an outcome of not using their product. However, this scenario is too dramatic, unusual, and even unethical, which may mislead the youth and the advert itself is not so effective. One improvement would be to use credible source to stress the importance and effectiveness by using this product.
Chaiken and Maheswaran (1994) conducted an experiment on the effect of source credibility on attitude judgment with reference to the heuristic-systematic theoretical framework. Participants were told that they would read and give their opinions about a new telephone answering machine, and then they read a booklet that conveyed the task importance, source credibility, and message type manipulations. Finally, they completed a questionnaire on their attitudes towards this telephone machine. As shown in the figure below, under low task importance, heuristic processing of the credibility cue was the sole determinant of participants’ attitudes, regardless of argument ambiguity or strength. When task importance was high and message content was unambiguous, systematic processing alone determined attitudes when this content contradicted the validity of the credibility heuristic; when message content did not contradict this heuristic, systematic and heuristic processing determined attitudes independently. Finally, when task importance was high and message content was ambiguous, heuristic and systematic processing again both influenced attitudes. These findings suggest that source credibility affected persuasion partly through its impact on the valence of systematic processing, confirming that heuristic processing can bias systematic processing when evidence is ambiguous. Therefore, the effect of credible source is considerable in heuristic processing on which most commercials aim to exert an impact.
In the case of Dettol, a statement by a biological professional or a leader of health campaign (maybe accompanying with a statistical figure) would be a more effective way to promote their products.
Chaiken, S., & Maheswaran, D. (1994). Heuristic processing can bias systematic processing: effects of source credibility, argument ambiguity, and task importance on attitude judgment. Journal of personality and social psychology, 66(3), 460.