"I'm My Own Grandpa" (sometimes rendered as "I'm My Own Grandpaw") is a novelty song written by Dwight Latham and Moe Jaffe, performed by Lonzo and Oscar in 1947, about a man who, through an unlikely (but legal) combination of marriages, becomes stepfather to his own stepmother — that is, tacitly dropping the "step-" modifiers, he becomes his own grandfather.
In the 1930s, Latham had a group, the Jesters, on network radio; their specialties were bits of spoken humor and novelty songs. While reading a book of Mark Twain anecdotes, he once found a paragraph in which Twain proved it would be possible for a man to become his own grandfather. In 1947, Latham and Jaffe expanded the idea into a song, which became a hit for Lonzo and Oscar.
In the song, the narrator marries a widow with an adult daughter. Subsequently, his father marries the widow's daughter. This creates a comic tangle of relationships by a mixture of blood and marriage; for example, the narrator's father is now also his stepson-in-law. The situation is complicated further when both couples have children.
Although the song continues to mention that both the narrator's wife and stepdaughter had children by the narrator and his father, respectively, the narrator actually becomes "his own grandpa" once his father marries the woman's daughter.The narrator marries the older woman.
This results in the woman's daughter becoming his stepdaughter.
Subsequently, the narrator's father marries the older woman's daughter.
The woman's daughter, being the new wife of the narrator's father, is now both his stepdaughter and his stepmother. Concurrently, the narrator's father, being his stepdaughter's husband, is also his own stepson-in-law.
The narrator's wife, being the mother of his stepmother, makes her both spouse and step-grandmother.
The husband of the narrator's wife would then be the narrator's step-grandfather. Since the narrator is that person, he has managed to become his own (step-step)grandfather. The "step-step" concept applies because the step-father of your step-mother would be your step-step-grandfather, making a "double step" event possible.
The song continues withThe narrator and his wife having a son.
The narrator's son immediately becomes the half-brother of his stepdaughter, as the narrator's wife is the mother of both.
Since his stepdaughter is also his stepmother, then the narrator's son is also his own step-and/or half-uncle because he is the (half-)brother of his (step-)mother.
The Narrator's son would then become a brother-in-law to the narrator's father, because he is the (half-)brother of the father's wife.
The narrator's father and his wife (the narrator's stepdaughter) then had a son of their own.
The child would then become the narrator's grandson because he is the son of his (step-)daughter.
The son would also become the (half-)brother of the narrator because his father is also the narrator's.
According to a 2007 article, the song was inspired by an anecdote that has been published periodically by newspapers for well over 150 years. The earliest citation was from the Republican Chronicle of Ithaca, New York on April 24, 1822 and that was copied from the London Literary Gazette:
A proof that a man may be his own Grandfather.—There was a widow and her daughter-in-law, and a man and his son. The widow married the son, and the daughter the old man; the widow was, therefore, mother to her husband's father, consequently grandmother to her own husband. They had a son, to whom she was great-grandmother; now, as the son of a great-grandmother must be either a grandfather or great-uncle, this boy was therefore his own grandfather. N. B. This was actually the case with a boy at a school in Norwich.
An 1884 book, The World of Wonders, attributed the original "remarkable genealogical curiosity" to Hood's Magazine.
The cover version by Lonzo and Oscar was recorded in 1947, the same year that Latham and Jaffe released The Jesters original. A version by Guy Lombardo and The Guy Lombardo Trio became a hit in 1948. The song was also recorded by Phil Harris (as "He's His Own Grandpa"), Jo Stafford (as "I'm My Own Grandmaw"), Kimball Coburn, Homer and Jethro and "Jon & Alun" (Jon Mark and Alun Davies) on their record "Relax Your Mind" (1963).
A 1976 episode of The Muppet Show includes a skit in which the song is performed by the all-Muppet Gogolala Jubilee Jugband. In the movie The Stupids, Stanley Stupid, portrayed by Tom Arnold, sings "I'm My Own Grandpa" while on a talk show about strange families. The song was performed by American country music singer Ray Stevens, and can be heard on his 1987 album Crackin' Up! Willie Nelson performed the song on his 2001 album The Rainbow Connection. This song was also performed by Grandpa Jones, who sang it both at the Grand Ole Opry and on the TV show Hee Haw. It was also later recorded on the album Home is Where the Heart Is by David Grisman and on Michael Cooney's album of songs for children. Folk singer Steve Goodman included it in his live shows, and recorded it on his album "Somebody Else's Troubles". This song has also been recorded by an Australian Comedy Country Artist Chad Morgan and appears on an album "Sheilas, Drongos, Dills and Other Geezers" and also Australian Country Artist, Melinda Schneider with the Schneider Sisters. It has also been covered by the Asylum Street Spankers and released on the 2002 Bloodshot Records compilation "The Bottle Let Me Down." The humorous folk singer, Anthony John Clarke, frequently covers it in his gigs and has recorded it on his 2004 album Just Bring Yourself.
Professor Philip Johnson-Laird used the song to illustrate issues in formal logic as contrasted with psychology of reasoning, noting that the transitive property of identity relationships expressed in natural language was highly sensitive to variations in grammar, while reasoning by models, such as the one constructed in the song, avoided this sensitivity.
The situation is included in a set of problems written attributed to Alcuin of York, and also in the final story in Baital Pachisi; the question asks to describe the relationship of the children to each other. Alcuin's solution is that the children are simultaneously uncle and nephew to each other; he does not draw attention to the relationships of the other characters.
In the Baital Pachisi this is the only riddle that the wise King Vikrama cannot answer.
The song is referred to in Robert Heinlein's 1959 time travel paradox short story "—All You Zombies—", and a snippet is played on a jukebox in the 2014 movie Predestination, which is based on that story.
The comedic television series Futurama includes the episode, "Roswell That Ends Well", which alludes to the song. In this episode, Fry accidentally time-travels back to the 1940s and gets his original grandfather killed. Since he remains alive, he falsely concludes that neither of his grandparents are really his grandparents. He then succumbs to his grandmother's seduction, thereby conceiving his father. Later, Professor Farnsworth derides Fry as "Mr. I'm-My-Own-Grandpa."
In the 1996 film The Stupids, Stanley Stupid sings the song in front of a talk show studio audience.
In "Synchrony", an episode in the fourth season of the science fiction television show "The X-Files", Agent Dana Scully quotes the song to express her incredulity at Agent Fox Mulder's reasoning regarding a series of interconnected events.