The extraordinary status the Marassa hold in Haitian Vodou reflects a much older and wider West African reverence for twins, most extensively documented among the Yoruba people of what is now southwestern Nigeria, who have long recorded one of the highest natural twin-birth rates of any human population and who developed an elaborate set of religious customs around the ibeji, the sacred twins. When a Yoruba twin dies, whether in infancy or later in life, a small carved wooden figure, an ere ibeji, is traditionally commissioned and cared for by the surviving family as a dwelling place for the dead twin's spirit, washed, dressed, fed symbolically and kept close, since twins are considered to share a single soul between two bodies, so that the loss of one endangers the spiritual completeness of both.
Ibeji figures are among the most widely collected and exhibited categories of traditional Yoruba sculpture in museums of African art worldwide, valued both artistically and as a striking material expression of this specific religious worldview. Vodou's veneration of the Marassa as sacred children who precede all the other lwa in ritual honor, and its treatment of twin birth as marking a special, potent connection to the spirit world, descends from this same deep West African religious complex, carried to Haiti primarily through Fon and Yoruba-descended populations and reshaped, like so much else in the tradition, into its own distinctively Haitian form while preserving the core conviction that twins are not simply two children but a single, doubled sacred force requiring particular ritual attention and respect.