Logical Flaws in Reasoning: Flawed Reasoning, Arguments, and Attitudes
Barnum Effect & Gullibility
A common reference point as to why people believe the advice of psychics and astrologers - not to mention many other nice things said about them - is the 'Barnum Effect.' Named after P.T. Barnum, the Barnum Effect is based upon his famous saying 'There's a sucker born every minute.'
Black & White Thinking
Human beings have a need to categorize everything; this is not a fault but rather an asset. Without our ability to take isolated instances, gather them together in groups, and make generalizations, we wouldn't have math, language, or even the ability for coherent thought. Without an ability to generalize from the specific to the abstract, you...
This is less a flaw in the reasoning process than a flaw in the argument or deliberation process. Just because too many words have been expended on explaining an idea or position doesn't mean that there is either anything wrong with the conclusion or with the process which led a person to that conclusion. It is, however, a barrier to communicating these ideas to others.
Unskilled and Unaware: Overconfidence in Self-Assessment
Being mistaken about something is not by itself a flaw in a person's reasoning process, and neither is being unskilled when it comes to constructing and analyzing logical arguments. However, the worse a person is at such tasks, the less likely they are to realize it, the more likely they are to overestimate their abilities, and the less likely...
Bias and Vested Interest: Interpreting Facts Unreasonably
An important thing to watch for in arguments - both our own and those offered by others - is the influence of bias or vested interest. Both are variations on the same sort of problem, although there are differences that require mentioning each separately. Bias occurs any time that facts are interpreted in a way that unreasonably favors one position over another; vested interest is a cause of bias in which one will personally and specifically benefit if people adopt a particular position.
Subjective Validation: Seeing Patterns & Connections That Aren't There
Subjective Validation is also sometimes called the 'personal validation effect' because it refers to a process by which people accept some claim or phenomenon as valid based solely upon a few personal experiences and/or subjective perception.
Propaganda and Persuasion: Misuse of Language and Meaning
When most people think of propaganda, they tend to think of the posters and songs created by or with the aid of a government during wartime, yet the truth of the matter is that propaganda has a much broader application. It refers not only to efforts by a government to get people to adopt certain beliefs or attitudes, but it can also be applied...
Self-Deception: Sometimes We Mislead Even Ourselves
If deception is the process of misleading others in order to get them to accept something as true even when it is false, then self-deception is the process of misleading yourself so that you will accept something as true even when you should acknowledge that it is false.
Economy with the Truth: Selectively Withholding Embarrassing Evidence - Flaws...
Everyone wants to be right - this is a truism which hardly seems to need repeating, but it is a vital motive which does need to be addressed. Our participation in debates and discussions is often predicated upon this motive - we want to learn what is right, we want to convince others that we are right, and/or we we want to get others to believe...
Confirmation Bias: Selective Use of Evidence to Support Our Beliefs
Confirmation bias occurs when we selectively notice or focus upon evidence which tends to support the things we already believe or want to be true while ignoring that evidence which would serve to disconfirm those beliefs or ideas. Confirmation bias plays a stronger role when it comes to those beliefs which are based upon prejudice, faith, or...
Avoiding the Question: Not Answering Challenges to a Claim
When trying to make a case for some idea, we encounter questions which challenge the coherency or validity of that position. When we are able to adequately answer those questions, our position becomes stronger. When we cannot answer the questions, then our position is weaker. If, however, we avoid the question altogether, then our reasoning process is revealed as weak.
Anecdotal Evidence & Testimonials: Lack of Independent Confirmation
Whenever we offer an empirical claim as true, we are expected to support that claim with evidence - pieces of information which, when taken together, tend to point to the truth of our claim. Evidence which proves our claim is best, but not absolutely required.
Wishful Thinking & Rationalization
It seems unlikely that, for anyone alive today, the world is exactly the way they wish it would be in every detail. Because there is discordance between what is the case and what we wish the case would be, we all engage at some point in time in wishful thinking: the desire that our situation be something other than it really is.
Vagueness: Inhibiting Communication Through Lack of Precision
Generally speaking, the best arguments also tend to be the more precise arguments. Precision in arguments is an important step in making them more coherent and more comprehensible. Precision means that both the arguer and the listener are able to develop a better grasp of what the argument says and means. It follows that vagueness in an enemy of...
Sophistry: Deliberately Flawed and Fallacious Arguments
An argument which appears to be quite valid but is in reality invalid is one which suffers from any of a number of fallacies or other flaws. We should expect to see this sort of thing because most people do not reason very well and no one reasons perfectly. Fallacious arguments, then, are natural - but what is not so natural is to offer fallacious and flawed arguments deliberately.
Repetition: Argumentum Ad Nauseam
Sometimes, people seem to think that the more they repeat an idea, the more likely it is that someone else will believe it. In other words, they are trying to convince people of something not based upon reasons or evidence, but instead upon sheer repetition. But why do some think that such a tactic will work?
Pedantry: Details at the Expense of Substance
Very often, debates become embroiled over what appear to be very minor issues. Sometimes this may be appropriate and sometimes it may not - when it is not, there is a strong possibility that no further productivity will occur in the discussion. When someone moves a discussion into an inappropriate and unproductive focus on minor issues, he can be accused of pedantry.
Why People Are Irrational about Politics (and Religion)
How can people agree that rationality is important but ignore rationality when it comes to important beliefs? The answer has to do different types of rationality: epistemic rationality vs. instrumental rationality.