Do generational curses exist in Hinduism?
Yes, generational curse do exists. They are of 2 types:
Such kind of curse may come from a strong and austere personality like a Brahman or a saintly person. There are couple of references in AnushAsanika Parva as footnotes:
The thin bamboo rod in the hand of the Brahmana is mightier than the thunderbolt of Indra. The thunder scorches all existing objects upon which it falls. The Brahmana's rod which symbolizes the Brahmana's might in the form of his curse blasts even unborn generations. The might of the rod is derived from Mahadeva.
Here is a small instance:
Once Brahma asked Surabhi to bear evidence before Vishnu to the statement that Brahma has seen the foremost part of Siva. Surabhi having given false evidence out of fear for Brahma was cursed by Siva that her offspring will eat unholy substances.
From this answer, a very [in]famous curse was given by GAndhAri to lord Krishna, which was so sharp that, the whole Yadu race met with rather a too quick annihilation to be able to witness further generational curse.
That comes from the ancestors of the same family itself, also known as Pitru runa or Pitru dosha. Usually, our ancestors live in subtle forms with their mental desires still unfulfilled. If such desires are not fulfilled by subsequent generations, then these desires are gradually transformed into curse and create various obstacles for ongoing generations. One reason for such Pitru dosha is shortly discussed in Gita:
BG 1.42 And the hybridisation in the family leads the ruiners of the family into hell only. The forefathers of these fall down (into hell) because of being deprived of the offerings of food and water.
Personally I know a very close friend, whose family was diagnosed with a curse, where no male child was getting born. Even if born, then it won't survive. They visited PrAchi, Gujarat, India for an intense ritual to lower down its effect.
We may wonder, why some misdeed of our forefathers have to be paid by us? That's because, a major [material] part of our father gets born as our own self. There are numerous references in ancient scriptures, which suggest that the father is born as a son/daughter. Hence, in a way we can assume that our great-great forefather's [material] part has born our own selves.
Here is one such reference by Bhishma while discussing fair property distribution among son & daughter:
"Bhishma said, 'The son is even as one's own self, and the daughter is like unto the son. How, therefore, can another take the wealth when one lives in one's own self in the form of one's daughter?
Traditionally in earlier times, the daughters would change the family after marriage. Hence, any forefather effect could be subsidising in their case.
Common people giving curse should be ignored & the receiver of the curse should grant them a pardon. Usually such curses will go in below category:
Note: “The question: Do generational curses exist in Hinduism?” is licensed by Stack Exchange Inc (https://hinduism.stackexchange.com/); user contributions licensed under CC BY-SA.