How we change what others think, feel, believe and do
When a little negative information is presented about something after significant positive information, the thing will be considered more attractive than if only the positive information is provided.
We evaluate through comparison and the negative information provides this. This is the contrast effect, with the small negative thing making the larger positive aspects seem even more positive.
Negative information can have a better effect when the person is not thinking carefully and logically, where positive information has more rational weight. This is because the contrast effect that the negative information supports is a heuristic, needing less mental processing.
Imperfection makes things seem more 'real' and slight imperfection is often better than the clinical sterility of absolute perfection. Flawless diamonds can be manufactured, yet natural, flawed diamonds are far more valuable.
Leaders use this effect when they admit to certain vulnerabilities. Of course these are in areas that are unimportant for their job, such as their difficulty in some sports or weakness for chocolate ice-cream.
Shiv and Tormala asked subjects about purchase of one item from hiking boots, chocolate bars, or champagne glasses, presenting them with positive and negative facts about the products. They were given positive and negative information. When the negative information was weak, such as limited choice for the shade of the boots. It was found that those who were deliberately distracted preferred the boots where negative information was added. Those who were not distracted preferred those with only positive information.
A set of reviews of a holiday destination that is all glowing 'five stars' may seem too good to be true. If there are a few slight niggles, then it may be found more attractive.
A similar effect is where a 'beauty spot' on a woman's face is a blemish, but is often considered attractive. Lots of such spots would be thought very unattractive.
When persuading, give positive information, then some minor negative information. Do not give them time to consider all this carefully. Distract them afterwards or ask for a quick decision.
When people offer minor negative information along with overwhelming positive information, watch out for them trying to persuade you.
Ein-Gar, D., Shiv, B., & Tormala, Z.L. (in press, 2011). When blemishing leads to blossoming: The positive effect of negative information. Journal of Consumer Research.
And the big