The Skeptics' Guide to the Universe: How to Know What's Really Real in a World Increasingly Full of Fake

by Steven Novella

NAME THAT LOGICAL FALLACY

11.

Skeptics’ Guide Entry: Cognitive Biases and Heuristics

The confidence people have in their beliefs is not a measure of the quality of evidence but of the coherence of the story the mind has managed to construct. —Daniel Kahneman

A cognitive bias is a tendency to think in a certain way, to favor certain kinds of information, and to prefer some conclusions over others. Biases generally deviate your thinking away from reality.

Heuristics are mental shortcuts. They are rules of thumb that allow you to approximate a likely answer quickly, but they’re not strictly true and often result in error.

Cognitive Biases

Heuristics

12.

Skeptics’ Guide Entry: Confirmation Bias

Confirmation bias is the tendency of individuals to seek out or interpret new information as support for previously held notions or beliefs, even when such interpretations don’t hold up to statistical scrutiny.

Confirmation bias is a tendency to notice, accept, and remember information that appears to support an existing belief and to ignore, distort, explain away, or forget information that seems to contradict an existing belief.

Confirmation bias is often subtle and nuanced, and because of this, it’s especially pernicious.

Confirmation bias is a more unconscious bias. This error in our thinking is constantly working in the background to undermine the rational process. It’s lurking within us and we must always be on the lookout.

This is why confirmation bias has such a strong effect. It gives us the confident illusion that we are following the evidence. In reality, our beliefs are manufacturing the evidence. In the end we may be extremely confident in a totally false belief.

Another factor that plays into confirmation bias is the use of open-ended criteria, like ad hoc or post hoc analysis. We often decide after we encounter a bit of information that this information confirms our belief, and we retrofit the new data into our belief as confirmation. We may call this subjective validation—the tendency to use subjective criteria to validate our prior beliefs.

There’s a closely related bias called desirability bias. We are biased toward information that supports what we want to be true, even if we don’t already believe it.

Psychologically, there are different kinds of beliefs—people treat emotionally held beliefs differently from emotionally neutral beliefs. We happily update the latter when we receive new information, but we cling tightly to the former and may even tighten our grip in the face of disconfirming information (a backfire effect).

It’s important to remember that knowing about cognitive biases doesn’t make you immune to them.

13.

Skeptics’ Guide Entry: Appeal to Antiquity

Section: Metac...

See also: Logical ...

The appeal to antiquity is a special form of the appeal-to-authority fallacy. In this case the alleged authority is the assumption of ancient wisdom, or the notion that an ide...

Astrology represents a vision of the universe devoid of any real knowledge of cosmology or the forces of nature. It’s a superstitious belief from a time before modern science existed, when the basics of logic, such as cause and effect, weren’t routinely applied.

Millions of people can believe something for thousands of years, even if that belief has no basis in reality.

Not until the medical profession explicitly adopted scientific methods to test their ideas did the four humors lose favor—time itself was not enough.

The bottom line is that time itself doesn’t establish whether or not an idea is valid or a claim is true. We still need to rely on logic and evidence.

14.

Skeptics’ Guide Entry:

Appeal to...

The appeal to nature is a logical fallacy based upon the unwarranted assumption that things that are natural are inherently superior to things that are manufactured. Additionally, it relies upon a vague definition of “natural.”

The appeal-to-nature fallacy is related to the naturalistic fallacy as a special case—some things that are good are natural, so all things natural must be good.

The flip side of the appeal-to-nature coin is that anything that is “unnatural” is inherently tainted to some degree.

The appeal-to-nature fallacy falls apart quickly upon examination of its two main pillars. The first pillar is that things in nature tend to be good for humans. The second is that we can operationally define “natural.”

Some natural poisons, in purified and carefully measured doses, can be exploited for their physiological effects. We call such poisons “drugs.” But make no mistake: The plants in which we find these substances use them for chemical warfare against anything that would eat them.

How much processing makes something unnatural?

The US Food and Drug Administration (FDA), the agency responsible for the safety and efficacy of our food, medicine, and other consumables, refers to “natural” as follows:

From a food science perspective, it is difficult to define a food product that is “natural” because the food has probably been processed and is no longer the product of the earth. That said, FDA has not developed a definition for use of the term natural or its derivatives. However, the agency has not objected to the use of the term if the food does not contain added color, artificial flavors, or synthetic substances.

In other words, in the US anyway, there is no legal definition of the term “natural” and the FDA has decided to just look the other way if companies decide to market their...

The organic food industry, for example, doesn’t allow the use of synthetic pesticides but does allow the use of so-called “natural” pesticides. In many cases the natural pesticides are less effective and more damaging to the environment than their synthetic alternatives. Some natural pesticides, like copper sulfate and rotenone, can be highly toxic. And yet they’re not viewed with the same caution, simply because they are “natural.”

15.

Skeptics’ Guide Entry: Fundamental Attribution Error

The fundamental attribution error is a cognitive bias in which we ascribe other people’s actions to internal factors such as personality while rationalizing our own actions as being the result of external factors beyond our control.

We are never aware of all the factors that influence someone else’s behavior.

It’s not just other people’s memories that are flawed, it is also our own. Not only are other people guilty of overestimating their knowledge, we overestimate our own too.

While it does take vigilance, this bias is surprisingly simple to correct. First, recognize that you never have all the information. Next, withhold judgment and give other people the benefit of the doubt.

16.

Skeptics’ Guide Entry: Anomaly Hunting

An anomaly is something that sticks out because it doesn’t seem to make sense or it appears to contradict established knowledge or scientific theory. The fallacy of anomaly hunting comes from looking for anything unusual, assuming any apparent anomaly is unexplainable, and then concluding that it is evidence for one’s pet theory.