The human brain is a mysterious thing.
A new study has revealed that when there's a delay between seeing an ad and buying a product, consumers tend to buy more of a product that advertises potentially harmful side effects, like weight gain and heart disease, than products that do not.
Researchers predicted that such warnings end up having the paradoxical effect of making customers trust a product that includes negative information about itself.
To test their hypothesis, researchers at New York University, Israel University and INSEAD, a business school in Singapore, performed four similar studies on men and women of various age groups between 2010 and 2012.
In one case, researchers showed a cigarette ad to a group of smokers. Half the participants saw a version of the ad with a health warning, while the other saw the same ad but without any mention of potential side effects.
The participants were then asked how many packs of the cigarettes they wanted to buy. Half the group was told the smokes would arrive within 24 hours, and the other half was told the cigarettes wouldn't arrive for three months.
What happened? Among those who were told they'd have to wait three months for the cigarettes to arrive, participants who had seen the ad with health warning ordered significantly more cigarettes than those who hadn't.
Researchers note that it is counterintuitive that warnings about sometimes dire health issues actually end up making consumers have higher confidence in a product that can harm them. They also note the consequences of such a tendency.
"This effect may fly under the radar since people who try to protect the public — regulatory agencies, for example — tend to test the impact of a warning shortly after consumers are exposed to it," psychological scientist and study co-author Ziv Carmon said in a statement. "By doing so, they miss out on this worrisome delayed outcome."
Interestingly, the idea to perform the study sprouted after researchers noticed that ads had become increasingly detailed and scary in listing potential side effects. "It then occurred to us that such warnings might perversely boost rather than detract from the appeal of the risky product," Carmon said.
While the U.S. Food and Drug Administration requires that prescription drug advertisements "present a 'fair balance' of information relating to the drug's risks and benefits," it does not review all ads before they are televised. In addition, the FDA does not require drug companies to say what percentage of people who take a drug will benefit from it.
The findings were published in the September 2013 issue of the journal Psychological Science.