 What's the difference between skepticism and denial? They can look similar because denial arguments are often presented as if they're real skepticism. But when you look under the surface, they're actually polar opposites. Skepticism is at the heart of the scientific method. A genuine skeptic doesn't come to a conclusion until they've considered the evidence. That's why it took many years for the scientific community to accept the fact that the earth is warming because of human greenhouse gas emissions. Scientists were skeptical until the evidence became overwhelming. In contrast, someone who denies well-established science comes to a conclusion first and then rejects any evidence that conflicts with their beliefs. So what you really want to know is how to tell the difference between skepticism and denial. Are there any telltale characteristics of science denial? Over the years, there have been many different occasions when groups of people denied a scientific consensus, for example the link between smoking and cancer, or that humans evolved from lower life forms, and more recently human cause global warming. All these forms of denial focus on different areas of science, but a scientific paper by Pascal Diethelm and Martin McKee found that regardless of which science is being targeted, all denial shares five characteristics. Diethelm and McKee identify them as fake experts, logical fallacies, impossible expectations, cherry picking, and conspiracy theories. I've found that an easy way to remember them is using the acronym FLIC. Let's have a closer look at each one. Firstly, fake experts are used to create the impression of an ongoing scientific debate. The general public rely on expert opinion as a guide for their own beliefs about science. For this reason, casting doubt on a scientific consensus is a key strategy for those looking to manufacture doubt about the science. Fake experts appear to be highly qualified, but don't have actual expertise in a relevant scientific field. An alternative way to portray the impression of an ongoing scientific debate is to magnify those few remaining scientists who continue to disagree with the consensus position. There are still a handful of apparently credentialed scientists who deny that HIV causes AIDS. While their views have lost respectability in the scientific community, they still continue to create doubt in the public's mind. Number two is logical fallacies. These are logically false arguments that lead to an invalid conclusion. For example, a red herring is a logical fallacy that distracts people with an irrelevant piece of information. Someone might argue that carbon dioxide is a colorless invisible gas, so therefore it's not a problem. But the fact that carbon dioxide is invisible is irrelevant to whether greenhouse gases affect climate. The argument is a red herring. A number of logical fallacies fall under this umbrella. These include misrepresenting or oversimplifying the science. Making faulty leaps of logic is called jumping to conclusions. And presenting only two choices when other options are available is called a false dichotomy. These all appear in myths that cast doubt on climate science. The third characteristic of science then are involves impossible expectations. This demands unrealistic standards of proof before acting on the science. This strategy was pioneered by the tobacco industry. They'd highlight any uncertainty in order to obscure the scientific consensus linking smoking and cancer. Whenever additional evidence linked smoking to cancer, they'd raise the standard of proof and claim insufficient evidence. Fourth, there's cherry picking, which focuses on specific pieces of data often out of context, while excluding any data that conflicts with the desired conclusion. But how do you tell when someone is cherry picking? When their conclusion from a small piece of data is different from the conclusion supported by the full body of evidence. Fifth and finally, when someone disagrees with an overwhelming scientific consensus, there is always a resort to conspiracy theories. How else would you explain that all the world's experts, scientific organizations and journals agree on something that you disagree with? The only explanation must be that the experts are all conspiring to falsify or exaggerate the science. That's why there were so many people who believe that AIMS was created by the US government. So those are the five characteristics of science then are. But here's an important point. Just because these techniques distort the science, doesn't mean they're deliberately deceptive. So let's go through the five characteristics of Fleck, looking at how they can arise from unconscious biases that operate at a psychological level. Firstly, let's look at fake experts. People tend to attribute more expertise to those who agree with their existing beliefs and values. So if you ask someone what scientists think about an issue, they'll do a mental survey of experts they remember. People are then more likely to recall experts who they agree with. This results in a distorted perception of scientific consensus. The more you disagree with a consensus position, the lower you think that consensus is. Second, logical fallacies can arise from confirmation bias, which is a tendency to favor evidence that confirms our beliefs. For example, people can misrepresent an opponent's position by focusing on their weaker arguments while ignoring their stronger arguments. This is known as a straw man argument. Third, the flip side of confirmation bias is disconfirmation bias, which occurs when threatening evidence is vigorously resisted. This results in demanding higher levels of proof for evidence that conflicts with their beliefs. In other words, impossible expectations can be a result of disconfirmation bias. A fourth example is cherry picking. This can also result from confirmation bias, putting more weight on agreeable information or downplaying disagreeable evidence. We remember the hits, but tend to forget the misses. For example, in one study, people were told about a breakdown at a nuclear power plant. Pro-nuclear participants focused on the fact that the safeguards worked. In contrast, nuclear opponents focused on the fact that the breakdown happened at all. In the end, both groups strengthened their original belief. The fifth characteristic is conspiracy theories. A number of studies have found that people who deny climate science are more likely to show conspiratorial thinking. For example, one study found that for people who denied climate change, the most common response to the mention of climate change was conspiracy theories, or the belief that climate change was a hoax. About 20% of the people in America, and around 15% in the United Kingdom, to varying degrees agree with the proposition that climate change is a hoax. It might be easy to accuse someone of intentionally trying to deceive us when they present arguments that oppose the scientific consensus. But the science of science denial tells us that these same arguments can arise from unconscious psychological processes. To the outside eye, genuinely held but false beliefs or misinformation can be indistinguishable from intentional deception or disinformation. That means you're on more solid ground addressing the techniques of denial rather than trying to discern the motives of an individual. In fact, focusing on motive can be counterproductive as it can provide opportunity to evade the scientific arguments. By understanding the techniques of denial and the psychology underlying it, you're better equipped to respond to expressions of science denial.