The following is a direct quote from Kahneman’s book:
Framing effects: Different ways of presenting the same information often evoke different emotions.
The statement that “the odds of survival one month after surgery are 90%” is more reassuring than the equivalent statement that “mortality within one month of surgery is 10%.”
Similarly, cold cuts described as “90% fat-free” are more attractive than when they are described as “10% fat.”
The equivalence of the alternative formulations is transparent, but an individual normally sees only one formulation, and what she sees is all there is.
Running Down Vimy 