The futility of trying to change opinion through information is demonstrated yet again by a recent study by Nylan, et al. (http://www.dartmouth.edu/~nyhan/vaccine-misinformation.pdf or PEDIATRICS Vol. 133 April 1, 2014 pp. e835-e842 (doi:10.1542/peds.2013-23652014)). They studied the ability of information to change parents’ opinion about having their children vaccinated.
Nylan, Reifler, Exeter, Richey, and Freed communicated with 759 parents of children under 17. The parents were sent one of four messages: (1) information from the Center of Disease Control (CDC) explaining there is no evidence that the measles, mumps, rubella (MMR) vaccine causes autism, (2) information about the dangers of the diseases prevented by the MMR vaccine, (3) pictures of children with the diseases that the MMR vaccine prevents, and (4) a story from a CDC fact sheet about a baby who almost died from measles. These are messages commonly used by public health agencies to promote vaccination.
They found that none of the messages increased parents’ intention to vaccinate a future child.
Parents’ opinions on vaccinating their children are not based on careful consideration of the facts. Parents’ opinions are based on feelings, associations, the opinions of other parents, and dramatic stories about problems reportedly caused by vaccines.
Factual information won’t change an opinion that isn’t based on facts.