The story
Referring to Leo Tolstoy's 1877 novel Anna Karenina, which begins: “All happy families are alike; each unhappy family is unhappy in its own way.” Popularized by American scientist Jared Diamond (born 1937) in his 1997 non-fiction book Guns, Germs, and Steel, in which he uses it to illustrate why so few wild animals have been successfully domesticated throughout history.
Etymology from Wiktionary, CC BY-SA 4.0.