Decision-making and behavioral biases Many of these biases are studied for how they affect belief formation and business decisions and scientific research. Bandwagon effect — the tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink, crowd psychology, herd behaviour, and manias. Bias blind spot — the […]
Monthly Archives: September 2015
Tu Quoque Fallacy
The tu quoque fallacy is committed when it is assumed that because someone else has done a thing there is nothing wrong with doing it. This fallacy is classically committed by children who, when told off, respond with “So and so did it too”, with the implied conclusion that there is nothing wrong with doing […]
Subjectivist Fallacy
There are two types of claim: objective and subjective. Objective claims have the same truth-value for everyone. For example, the claim that the Earth is cuboid is an objective claim; it’s either true for everyone or false for everyone. It isn’t possible for the Earth to be cuboid for me, spherical for you, but flat […]
Sweeping Generalization Fallacy
A sweeping generalization applies a general statement too broadly. If one takes a general rule, and applies it to a case to which, due to the specific features of the case, the rule does not apply, then one commits the sweeping generalization fallacy. This fallacy is the reverse of a hasty generalization, which infers a […]
Slippery Slope Fallacy
Slippery slope arguments falsely assume that one thing must lead to another. They begin by suggesting that if we do one thing then that will lead to another, and before we know it we’ll be doing something that we don’t want to do. They conclude that we therefore shouldn’t do the first thing. The problem […]
Post Hoc Fallacy
The Latin phrase “post hoc ergo propter hoc” means, literally, “after this therefore because of this.” The post hoc fallacy is committed when it is assumed that because one thing occurred after another, it must have occurred as a result of it. Mere temporal succession, however, does not entail causal succession. Just because one thing […]
No True Scotsman Fallacy
The no true scotsman fallacy is a way of reinterpreting evidence in order to prevent the refutation of one’s position. Proposed counter-examples to a theory are dismissed as irrelevant solely because they are counter-examples, but purportedly because they are not what the theory is about. Example The No True Scotsman fallacy involves discounting evidence that […]
Hasty Generalization Fallacy
A hasty generalisation draws a general rule from a single, perhaps atypical, case. It is the reverse of a sweeping generalisation. Example (1) My Christian / atheist neighbour is a real grouch. Therefore: (2) Christians / atheists are grouches. This argument takes an individual case of a Christian or atheist, and draws a general rule […]
False Dilemma / Bifurcation Fallacy
The bifurcation fallacy is committed when a false dilemma is presented, i.e. when someone is asked to choose between two options when there is at least one other option available. Of course, arguments that restrict the options to more than two but less than there really are are similarly fallacious. Examples (1) Either a Creator […]
Cum Hoc Fallacy
The cum hoc fallacy is committed when it is assumed that because two things occur together, they must be causally related. This, however, does not follow; correlation is possible without causation. This fallacy is closely related to the post hoc fallacy. Example As the graph below (taken from the Church of the Flying Spaghetti Monster […]