"Simply denying mainstream science based on flimsy, invalid and too-often agenda-driven critiques of science is not skepticism at all. It is contrarianism ... or denial," Mann told LiveScience.
Instead, true skeptics are open to scientific evidence and are willing to evenly assess it.
"All scientists should be skeptics. True skepticism is, as [Carl] Sagan described it, the 'self-correcting machinery' of science," Mann said.
5. Nature vs. nurture
The phrase "nature versus nurture" also gives scientists a headache, because it radically simplifies a very complicated process, said Dan Kruger, an evolutionary biologist at the University of Michigan.
"This is something that modern evolutionists cringe at," Kruger told LiveScience.
Genes may influence human beings, but so, too, do epigenetic changes. These modifications alter which genes get turned on, and are both heritable and easily influenced by the environment. The environment that shapes human behavior can be anything from the chemicals a fetus is exposed to in the womb to the block a person grew up on to the type of food they ate as a child, Kruger said. All these factors interact in a messy, unpredictable way.
Another word that sets scientists' teeth on edge is "significant."
"That's a huge weasel word. Does it mean statistically significant, or does it mean important?" said Michael O'Brien, the dean of the College of Arts and Science at the University of Missouri.
In statistics, something is significant if a difference is unlikely to be due to random chance. But that may not translate into a meaningful difference, in, say, headache symptoms or IQ.
"Natural" is another bugaboo for scientists. The term has become synonymous with being virtuous, healthy or good. But not everything artificial is unhealthy, and not everything that's natural is good for you.
"Uranium is natural, and if you inject enough of it, you're going to die," Kruger said.
Natural's sibling "organic" also has a problematic meaning, he said. While organic simply means "carbon-based" to scientists, the term is now used to describe pesticide-free peaches and high-end cotton sheets, as well.
But though these words may be routinely misunderstood, the real problem, scientists say, is that people don't get rigorous science education in middle school and high school. As a result, the public doesn't understand how scientific explanations are formed, tested and accepted.
What's more, the human brain may not have evolved to intuitively understand key scientific concepts such as hypotheses or theories, Kruger said.
Most people tend to use mental shortcuts to make sense of the cacophony of information they're presented with every day.
One of those tendencies is to make a "binary distinction between something that is true in an absolute sense and something that's false or a lie," Kruger said. "With science, it's more of a continuum. We're continually building our understanding."
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