The fear among many Americans to fully embrace vaccines arises not from a distrust in science, misinformation, or failures of understanding, but from divisive forces that turn scientific findings into uninformed politically charged controversies, a new report argues.

Published in this week’s edition of Science magazine, the study comes from Dan M. Kahan, law and psychology professor and director of the Cultural Cognition Project at Yale Law School. Kahan’s report tackles an ongoing topic of research, one that paints science communication as operating in an environment where “cultural cognition,” the tendency for groups to fit assessments of risk into ideological compartments, maintains a stranglehold on public perception of vaccines.

Kahan uses the examples of HPV (human papillomavirus) and HBV (hepatitis B), two sexually transmitted diseases that can each lead to cancer, as his point of departure. Health officials recommended that certain age groups get each vaccine, but because of how the public learned about them through the information channels, HPV now faces alarmingly low rates of vaccination, while HBV tells a more hopeful story.

"It was likely inevitable," Kahan wrote, "that people of opposing cultural orientations would react divergently to a high-profile campaign to enact legislation mandating vaccination of 11- to 12- year-old girls for a sexually transmitted disease. Yet there was nothing inevitable about the HPV vaccine being publicly introduced in a manner so likely to generate cultural conflict."

The campaign that Kahan refers to is a 2006 proposal from the Centers for Disease Control and Prevention (CDC), which recommended the universal immunization against the disease among adolescent girls. Every state but one shot down legislative action for the mandate. Kahan believes that it was a communication breakdown.

"The unusual conditions under which the HPV vaccine was introduced explains the difference," he said.

When the U.S. Food and Drug Administration (FDA) first started the approval process for the HPV vaccine, called Gardasil, the company producing it, Merck, was granted fast-track approval process of the “girls-only” version of the drug. Merck then encouraged state lawmakers to make Gardasil mandatory to begin school enrollment, a move widely viewed as a preemptive attempt to gain control of the market.

The problem, as Kahan views it, is that parents subsequently found out about the drug because of the brewing “mandatory girls-only STD shot,” rather than from their pediatrician — the way the HBV vaccine was first introduced — inspiring fear and arousing cultural cognition dynamics.

"Parents do trust their pediatricians on the HBV vaccine," wrote Kahan, arguing that HPV first surfaced in a bad light, making it harder for parents to trust their doctors.

HBV "retained coverage of 90% of adolescents during the period when HPV mandates were being debated in state legislatures," he continued. “The rate for completing the HPV immunization series now stands at an anemic 33% for adolescent girls, and 7% for boys."

Parents who first heard about the HPV vaccine being just for adolescent girls immediately feared the worst. Skeptical right-wingers learned to believe that vaccination would increase their daughters’ sexual promiscuity, prompting widespread rejection.

Meanwhile, the HBV vaccine saw a far less high-profile introduction, as states gradually began to adopt legislation when the CDC recommended both boys and girls get the shot.

"Many public health experts warned that the HPV vaccine was being introduced in a manner that risked provoking needless and disorienting controversy," Kahan said in a statement.

But the problem is not media sensationalism, he argues. The media may only fall prey to cultural cognition, too. When vaccine opponents become vocal, the natural tendency is to link the groups who appear to be in solidarity on the anti-science bandwagon. This creates the communication environment, Kahan says, that draws false controversies, lumping anti-vaccine people in with the folks who are anti-climate change and anti-evolution.

"Filling popular discourse with the claim that childhood vaccination is part of the same package of partisan stances as these issues," his article notes, "needlessly risks provoking the same cultural-cognition dynamics that impeded reasoned public engagement with the HPV vaccine."

Unfortunately, no mechanisms exist that allow the FDA or the federal government more generally to anticipate or avoid these recurring threats. The media, as a mouthpiece for the state of the science communication environment, merely operates within these faulty parameters.

"The problem isn't media sensationalism," Kahan concluded. "Uniformed and counterproductive risk communication is the inevitable byproduct of the absence of a systematic, evidence-based alternative."