The genetic fallacy is a logical fallacy based on the irrelevant appraisal of something based on its origin.
It occurs when one attempts to reduce the significance of an idea, person, practice, or institution merely to an account of its origin (genesis) or earlier form. This overlooks any difference to be found in the present situation, typically transferring the positive or negative esteem from the earlier context.
A Genetic Fallacy is a line of "reasoning" in which a perceived defect in the origin of a claim or thing is taken to be evidence that discredits the claim or thing itself. It is also a line of reasoning in which the origin of a claim or thing is taken to be evidence for the claim or thing. This sort of "reasoning" has the following form:
The origin of a claim or thing is presented.
The claim is true (or false) or the thing is supported (or discredited).
It is clear that sort of "reasoning" is fallacious. For example: "Bill claims that 1+1=2. However, my parents brought me up to believe that 1+1=254, so Bill must be wrong."
It should be noted that there are some cases in which the origin of a claim
is relevant to the truth or falsity of the claim. For example, a claim that
comes from a reliable expert is likely to be true (provided it is in her area of
"The current Chancellor of Germany was in the Hitler Youth at age 3. With that sort of background, his so called 'reform' plan must be a fascists program.""I was brought up to believe in God, and my parents told me God exists, so He must." "Sure, the media claims that Senator Bedfellow was taking kickbacks. But we all know about the media's credibility, don't we."