Post hoc, ergo, propter hoc, “after this, therefore, because of this,”… mistaken belief that temporal succession implies a causal relation
In Branding on March 1, 2010 at 12:23 amFrom Roy H. Williams’ Monday Morning Memo:
Violent crime in America declined each year from 1993 to 2004. Then just about the time the iPod became popular in 2005, violent crime began trending upward.
CONCLUSION: iPods cause violent crime. Or at least that was the conclusion of a 2007 report published by The Urban Institute, a research organization based in Washington. (I swear I’m not making this up.)
Bad advertising strategies stem from just such logic: “Since one event precedes another, the first event must be the cause of the second.” This fallacy of logic is so common it has a Latin name: Post hoc, ergo, propter hoc, “after this, therefore, because of this,” referring to the mistaken belief that temporal succession implies a causal relation.
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