In the city of Igbo-Ora in southwestern Nigeria, twins seem to be extremely common.
According to the local chief Jimoh Titiloye, almost every family in this area has twins or other multiple births.
The neighborhood has held an annual event to honor twins for the past 12 years. According to organizers, this year’s event, which took place earlier this month, attracted participants from as far away as France and featured more than 1,000 pairs of twins.
The high twin rate in Igbo-Ora, a population of at least 200,000 people located 135 kilometers (83 miles) south of Lagos, the largest city in Nigeria, has no known scientific reason.
However, a lot of Igbo-Ora people think it’s related to the diets of women.
Possibly there are items they consume there that have a high level of particular hormones that now result in what we call multiple ovulation
Igbo-Ora has a higher-than-average rate of fraternal twins, which may account for it, but there are also a lot of identical twins there. Instead of hyperovulation, those come from a single fertilized egg that splits into two.