Yes it is believed it might because they have a high consumption of a type of yam which stimulates eggs to be released from each ovary
Do you happen to know any twins? I do not, do you and would they be fraternal twins? Fraternal twins are those who each got fertilized by a sperm cell. What is the difference between fraternal and identical? Identical twins develop from one zygote, while fraternal develop from two different eggs So I guess then boy/girl twins are always fraternal. I'm not able to say, but each twin would be fertilized by their own sperm cell. It's very interesting how twins seem to run in certain families - is it hereditary? I'm honestly not aware of that, however have you heard of the Yoruba people? They have the highest rate for twins in the world, 90-100 twins for every 1000 live births! Wow - that is amazing - perhaps it also gives them a way to re-populate faster if there is some other kind of environmental reason
The Yoruba peoples have the highest rate of twinning in the world, at 45–50 twin sets (or 90–100 twins) per 1,000 live births, possibly because of high consumption of a specific type of yam containing a natural phytoestrogen which may stimulate the ovaries to release an egg from each side.