Origin 412 to 1546 CE
The doctrine holds that human beings begin damaged, and that the damage is not merely the sum of what each has done. Beyond that the traditions diverge sharply, and the divergence is old.
The Western doctrine, shaped by Augustine and defined at Trent in 1546, holds that the sin of Adam is transmitted to every descendant by propagation, that what is transmitted includes guilt as well as the loss of original holiness, and that baptism remits it. On this account an infant is genuinely in need of remission.
The Eastern churches speak of ancestral sin and mean something perceptibly weaker. What is inherited is mortality and a corrupted condition inclined to sin, not the personal guilt of an ancestor; no one is culpable for another's act. This is not a modern softening but a different reading of the same texts.
There is a philological fact underneath the split that is worth stating carefully. Romans 5:12 says in Greek that death spread to all "eph' ho" all sinned, a phrase whose sense is disputed, plausibly "because" or "inasmuch as". The Latin rendered it "in quo", "in whom", which reads naturally as all having sinned in Adam. Augustine, working from the Latin, built on that reading. It is a genuine overstatement to say the Western doctrine rests on a mistranslation, Augustine had other grounds, and the Greek fathers were not without a doctrine of the fall, but the Latin certainly made the inherited-guilt reading easier, and the Greek text does not require it.
Judaism, reading the same third chapter of Genesis, derives no doctrine of inherited guilt at all, which is a useful check on the assumption that the text compels one.