"Settled science"

nature presents some of "The science myths that will not die." The author observes:

Once a myth is here, it is often here to stay. Psychological studies suggest that the very act of attempting to dispel a myth leads to stronger attachment to it. In one experiment, exposure to pro-vaccination messages reduced parents' intention to vaccinate their children in the United States. In another, correcting misleading claims from politicians increased false beliefs among those who already held them. “Myths are almost impossible to eradicate,” says Kirschner. “The more you disprove it, often the more hard core it becomes.”

The scientific myths addressed:

• Myth 1: Screening saves lives for all types of cancer
  
• Myth 2: Antioxidants are good and free radicals are bad
• Myth 3: Humans have exceptionally large brains
• Myth 4: Individuals learn best when taught in their preferred learning style
• Myth 5: The human population is growing exponentially (and we're doomed)

In-service training indoctrinated us in the "learning style" approach throughout my time as a secondary school teacher. I was particularly interested in what the article had to say about that.

.... One such myth is that individuals learn best when they are taught in the way they prefer to learn. A verbal learner, for example, supposedly learns best through oral instructions, whereas a visual learner absorbs information most effectively through graphics and other diagrams.

There are two truths at the core of this myth: many people have a preference for how they receive information, and evidence suggests that teachers achieve the best educational outcomes when they present information in multiple sensory modes. Couple that with people's desire to learn and be considered unique, and conditions are ripe for myth-making. ....

In 2008, four cognitive neuroscientists reviewed the scientific evidence for and against learning styles. Only a few studies had rigorously put the ideas to the test and most of those that did showed that teaching in a person's preferred style had no beneficial effect on his or her learning. “The contrast between the enormous popularity of the learning-styles approach within education and the lack of credible evidence for its utility is, in our opinion, striking and disturbing,” the authors of one study wrote. ....

In the past few decades, research into educational techniques has started to show that there are interventions that do improve learning, including getting students to summarize or explain concepts to themselves. And it seems almost all individuals, barring those with learning disabilities, learn best from a mixture of words and graphics, rather than either alone.

Yet the learning-styles myth makes it difficult to get these evidence-backed concepts into classrooms. When Howard-Jones speaks to teachers to dispel the learning-styles myth, for example, they often don't like to hear what he has to say. “They have disillusioned faces. Teachers invested hope, time and effort in these ideas,” he says. “After that, they lose interest in the idea that science can support learning and teaching.”

Charles Krauthammer addressed another persistent myth last week:

When the federal government’s 1980 “Dietary Guidelines for Americans” warned about the baleful effects of saturated fats, public interest activists joined the fight and managed to persuade major food companies to switch to the shiny new alternative: trans fats. Thirty-five years later, the Food and Drug Administration finally determined that trans fats are not just useless but unsafe, and ordered them removed from all foods. Oops.

So much for settled science. .... [more]

The science myths that will not die : Nature News & Comment, Food fads: Make mine gluten-full - The Washington Post