The genetic fallacy (also known as the fallacy of origins or fallacy of virtue) is a fallacy of irrelevance where a conclusion is suggested based solely on someone's or something's history, origin, or source rather than its current meaning or context. This overlooks any difference to be found in the present situation, typically transferring the positive or negative esteem from the earlier context.
The fallacy therefore fails to assess the claim on its merit. The first criterion of a good argument is that the premises must have bearing on the truth or falsity of the claim in question. Genetic accounts of an issue may be true, and they may help illuminate the reasons why the issue has assumed its present form, but they are not conclusive in determining its merits.
According to the Oxford Companion to Philosophy (1995), the term originated in Morris Raphael Cohen and Ernest Nagel's book Logic and Scientific Method (1934).
Examples
From Attacking Faulty Reasoning by T. Edward Damer, Third Edition p. 36:
There are numerous motives explaining why people choose to wear wedding rings, but it would be a logical fallacy to presume those who continue the tradition are promoting sexism.
From With Good Reason: An Introduction to Informal Fallacies by S. Morris Engel, Fifth Edition, pg. 196: