The Yoruba peoples of Nigeria have one of the highest rates of twin births in the world. Such births indicate good fortune, as twins (ibeji) are considered to be spirited, unpredictable and fearless. Mothers of twins honour their special children by singing their praises and dancing in public places; people who give them gifts are blessed.

The death of a twin requires a unique ritual. Parents consult a diviner, who determines what must be done to appease the spirit of the deceased twin, lest it lure the living one to its realm. Usually, the diviner counsels that they should commission an ere ibeji (sacred image of a twin) for the deceased. He names the artist who is to carve the sculpture, and also determines the weekly and annual rituals that must be performed by the mother. The artist will receive specified gifts from the parents. When he has carved the ere ibeji, he will perform a ritual washing of the figure and rub it with special ointment. He will perform a sacrifice, bless the ere ibeji and present it to the mother, who will carry it on her back or in her wrapper as she would a living child.

The Lang collection holds several examples of ere ibeji. The figures are always shown in the prime of life, standing in a symmetrical pose. The two examples shown here display the typical adornments that the mother may add to the ere ibeji: indigo dye on the head, beads at neck and hip, strings of cowrie shells symbolizing wealth and status. The left-hand sculpture bears a silver-coloured nail in one eye; holes in the other eye areas indicate that such decoration may have once existed there, too.