Twins

Rates of identical twins are relatively constant worldwide at about 4 per 1000 births. Fraternal twins, on the other hand, show considerable variation in prevalence. African nations account for the highest number of naturally-conceived fraternal twins, while Asia has the lowest. In one report, twin rates were 1.3 per 1000 births in Japan, 8 per 1000 births in the United States and Europe, and 50 per 1000 births in Nigeria!

The Yoruba community of south-western Nigeria has the highest twinning rate in the world. Twin births have been woven into the fabric of Yoruba culture through a belief system that endows twins with special names and powers. Wooden statuettes, called Ibejis, represent the souls of deceased newborn twins and are involved in elaborate rituals.

According to The Guinness World Records, the oldest twins ever were born in Japan in 1892 (identical twins Kin Narita and Gin Kanie). Kin died in 2000, at the age of 107 years. The oldest male twins both lived to 105 years of age (Glen and Dale Moyer; born in 1895).