Stuart Firestein: The pursuit of ignorance (by TED)

If the government were to redefine normal weight as one that doesn’t increase the risk of death, then about 130 million of the 165 million American adults currently categorized as overweight and obese would be re-categorized as normal weight instead.
Academic Incentives Against Truth | EconTalk Interviews Brian Nosek

Incentives in academic life create a tension between truth-seeking and professional advancement. Nosek argues that these incentives create a subconscious bias toward making research decisions in favor of novel results that may not be true.

Consider the many filters that a study must pass — from approval by one’s advisor, to design, to data collection, to analysis and write-up, to refereeing, to editorial acceptance, to public dissemination. At each step, the sexy study has an advantage over less-sexy competitors. The cumulative advantage in the marketplace of ideas should make us nervous about forming our opinions based on what we see in the news.
Almost all those who have engaged in any form of inquiry have been wrong and misguided. That is our predicament: fallible investigators start from the conclusions of their fallible predecessors. Yet even the dedicated mathematical astronomers of the late Middle Ages who explored the complicated details of the equant point in Ptolemaic theory contributed to the advancement of the science, by supplying standards by which more promising post-Copernican systems might be judged, and by introducing possibilities and options into future debates.
We assume that more information will make it easier to find the cause, that seeing the soft tissue of the back will reveal the source of the pain, or at least some useful correlations. Unfortunately, that often doesn’t happen. Our habits of visual conclusion-jumping take over. All those extra details end up confusing us; the more we know, the less we seem to understand.
[M]uch of what biomedical researchers conclude in published studies—conclusions that doctors keep in mind when they prescribe antibiotics or blood-pressure medication, or when they advise us to consume more fiber or less meat, or when they recommend surgery for heart disease or back pain—is misleading, exaggerated, and often flat-out wrong.