In one Nigerian town, seeing twins is far from unusual.
Igbo-Ora, in southwestern Nigeria, has become famous for its exceptionally high number of twin births.
Research has reported a rate of around 45 sets of non-identical twins for every 1,000 live births in the community. That has helped give Igbo-Ora a reputation as one of the world’s great twin hotspots.
But there is still one big question.
Why are so many twins born there?
Nigeria’s famous town of twins
For generations, twins have been a prominent part of life in Igbo-Ora.
The unusually high rate mainly involves dizygotic twins, better known as fraternal or non-identical twins.
These twins develop when two separate eggs are fertilised during the same pregnancy.
Researchers have studied Igbo-Ora for decades. However, they have yet to identify a single cause that explains its unusually high twinning rate.
Is the secret in the food?
One of the most popular explanations comes from the local diet.
Residents have traditionally linked twin births to foods including ilasa, a soup made from okra leaves, and amala, which can be made from cassava or yam flour.
A 2020 study found that residents frequently mentioned ilasa and amala when asked why so many twins were born in their community.
Yams have also frequently been suggested as an explanation.
However, researchers have not proven that eating any particular food causes women in Igbo-Ora to conceive twins.
In fact, similar foods are eaten in neighbouring communities where twinning rates are lower.
Could genetics explain Igbo-Ora’s twins?
Genetics may also play a role.
Some residents believe twin births run in families, while researchers have examined whether inherited biological factors could increase the likelihood of women releasing more than one egg during ovulation.
A 2025 study compared these scientific possibilities with local explanations. It found that genetics, diet, environmental factors and maternal characteristics could all be relevant.
But once again, researchers did not identify one definitive explanation.
A mystery that remains unsolved
For people in Igbo-Ora, the phenomenon is about more than biology.
Local explanations can include family inheritance, food, water and even divine blessing.
Scientists continue to investigate the biological and environmental factors behind the phenomenon.
For now, however, the reason this Nigerian town produces so many twins remains something of a mystery.