McNamara fallacy - Deepstash





8 logical fallacies that are hard to spot

McNamara fallacy

This fallacy occurs when decisions are made based on observations or quantitative criteria while ignoring other factors.
Common phrase: "You can't measure that, so it's not important."




Logical Fallacies
Logical Fallacies

Logic is fundamental to most of humanity’s knowledge, but there are common fallacies in logic and reasoning, errors of judgement which happen due to:

  1. Our assumptions based on what we...
Correlation And Causation

If two incidents or things happen at around the same time does not mean that one thing is the result of the other. Often many things occur at the same time yet are completely unrelated.

A correlation of data, like:

1) Increase in social media usage, and

2) Increase in anxiety and depression

does not mean that one set of data is caused by the other.

The Slippery Slope

The Slippery Slope fallacy is a mistaken belief that one relatively mild unaddressed problem or allowance will automatically lead to other negative consequences.

The mind races on to the next negative consequence like a downward spiral, creating fear and anxiety.

False equivalence

It is a logical fallacy and it occurs when someone incorrectly asserts that two or more things are equal because they share some characteristics, regardless of the notable differences...

The problem with false equivalence
  • The equivalence exaggerates the degree of similarity. I.e, stating that two people share a specific personality trait, but ignoring that they differ in other aspects of this trait.
  • The equivalence exaggerates the importance of the similarity. I.e, focusing on a personality trait that two people share while ignoring that many other people also share this trait.
  • The equivalence ignores important differences.
  • The equivalence ignores differences in orders of magnitude. 
Responding to a false equivalence
  • Show that the similarities between the things being equated are exaggerated, overemphasized, or oversimplified.
  • Highlight the differences between the things being equated. 
  • Explain why these differences are more significant than related similarities.
  • Provide counterexamples.
  • Ask your opponent to justify why they believe that their equivalence is valid, and then demonstrate the issues with the reasoning they provide.
Convince Them With Confidence
  • Speak confidently, be concise, and try not to repeat yourself. 
  • Give the appearance that you truly know what’s right from the beginning, even if you don’t have all o...
Avoid Common Argument Fallacies

Winning an argument often comes down to who can go the longest without contradicting themselves and keeping sound logic, not direct persuasion of the other party.

Anecdotal Fallacy

Using a single personal experience as the foundation of your argument or your big piece of evidence. 

For example, your phone may have broken right after you bought it, but you can’t use that to argue that those phones are not worth the purchase for others.